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[proxmark3-svn] / armsrc / lfops.c
index 14cc33a4ab297396515200a1e2d0f0cc711f8481..995a8810ad6f856772e87a56111c475de9c29473 100644 (file)
 //-----------------------------------------------------------------------------
+// This code is licensed to you under the terms of the GNU GPL, version 2 or,
+// at your option, any later version. See the LICENSE.txt file for the text of
+// the license.
+//-----------------------------------------------------------------------------
 // Miscellaneous routines for low frequency tag operations.
-// Tags supported here so far are Texas Instruments (TI), HID
+// Tags supported here so far are Texas Instruments (TI), HID, EM4x05, EM410x
 // Also routines for raw mode reading/simulating of LF waveform
-//
 //-----------------------------------------------------------------------------
-#include <proxmark3.h>
+
+#include "proxmark3.h"
 #include "apps.h"
+#include "util.h"
 #include "hitag2.h"
 #include "crc16.h"
-
-void AcquireRawAdcSamples125k(BOOL at134khz)
-{
-       if (at134khz)
-               FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz
-       else
-               FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
-
-       FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);
-
-       // Connect the A/D to the peak-detected low-frequency path.
-       SetAdcMuxFor(GPIO_MUXSEL_LOPKD);
-
-       // Give it a bit of time for the resonant antenna to settle.
-       SpinDelay(50);
-
-       // Now set up the SSC to get the ADC samples that are now streaming at us.
-       FpgaSetupSsc();
-
-       // Now call the acquisition routine
-       DoAcquisition125k();
-}
-
-// split into two routines so we can avoid timing issues after sending commands //
-void DoAcquisition125k(void)
+#include "string.h"
+#include "lfdemod.h"
+#include "lfsampling.h"
+#include "protocols.h"
+#include "usb_cdc.h"
+#include "fpgaloader.h"
+
+/**
+ * Function to do a modulation and then get samples.
+ * @param delay_off
+ * @param period_0
+ * @param period_1
+ * @param command
+ */
+void ModThenAcquireRawAdcSamples125k(uint32_t delay_off, uint32_t period_0, uint32_t period_1, uint8_t *command)
 {
-       BYTE *dest = (BYTE *)BigBuf;
-       int n = sizeof(BigBuf);
-       int i;
-       
-       memset(dest, 0, n);
-       i = 0;
-       for(;;) {
-               if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXRDY) {
-                       AT91C_BASE_SSC->SSC_THR = 0x43;
-                       LED_D_ON();
-               }
-               if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY) {
-                       dest[i] = (BYTE)AT91C_BASE_SSC->SSC_RHR;
-                       i++;
-                       LED_D_OFF();
-                       if (i >= n) break;
-               }
-       }
-       Dbprintf("buffer samples: %02x %02x %02x %02x %02x %02x %02x %02x ...",
-                       dest[0], dest[1], dest[2], dest[3], dest[4], dest[5], dest[6], dest[7]);
-}
+       // start timer
+       StartTicks();
 
-void ModThenAcquireRawAdcSamples125k(int delay_off, int period_0, int period_1, BYTE *command)
-{
-       BOOL at134khz;
+       // use lf config settings
+       sample_config *sc = getSamplingConfig();
 
-       /* Make sure the tag is reset */
+       // Make sure the tag is reset
+       FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
        FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
-       SpinDelay(2500);
-       
-       // see if 'h' was specified
-       if (command[strlen((char *) command) - 1] == 'h')
-               at134khz = TRUE;
-       else
-               at134khz = FALSE;
+       WaitMS(2500);
 
-       if (at134khz)
-               FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz
-       else
-               FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
+       // clear read buffer (after fpga bitstream loaded...)
+       BigBuf_Clear_keep_EM();
 
-       FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);
+       // power on
+       LFSetupFPGAForADC(sc->divisor, 1);
 
-       // Give it a bit of time for the resonant antenna to settle.
-       SpinDelay(50);
        // And a little more time for the tag to fully power up
-       SpinDelay(2000);
+       WaitMS(2000);
+       // if delay_off = 0 then just bitbang 1 = antenna on 0 = off for respective periods.
+       bool bitbang = delay_off == 0;
+       // now modulate the reader field
 
-       // Now set up the SSC to get the ADC samples that are now streaming at us.
-       FpgaSetupSsc();
+       if (bitbang) {
+               // HACK it appears the loop and if statements take up about 7us so adjust waits accordingly...
+               uint8_t hack_cnt = 7;
+               if (period_0 < hack_cnt || period_1 < hack_cnt) {
+                       DbpString("Warning periods cannot be less than 7us in bit bang mode");
+                       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+                       LED_D_OFF();
+                       return;
+               }
 
-       // now modulate the reader field
-       while(*command != '\0' && *command != ' ') {
+               // hack2 needed---  it appears to take about 8-16us to turn the antenna back on 
+               // leading to ~ 1 to 2 125khz samples extra in every off period 
+               // so we should test for last 0 before next 1 and reduce period_0 by this extra amount...
+               // but is this time different for every antenna or other hw builds???  more testing needed
+
+               // prime cmd_len to save time comparing strings while modulating
+               int cmd_len = 0;
+               while(command[cmd_len] != '\0' && command[cmd_len] != ' ')
+                       cmd_len++;
+
+               int counter = 0;
+               bool off = false;
+               for (counter = 0; counter < cmd_len; counter++) {
+                       // if cmd = 0 then turn field off
+                       if (command[counter] == '0') {
+                               // if field already off leave alone (affects timing otherwise)
+                               if (off == false) {
+                                       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+                                       LED_D_OFF();
+                                       off = true;
+                               }
+                               // note we appear to take about 7us to switch over (or run the if statements/loop...)
+                               WaitUS(period_0-hack_cnt);
+                       // else if cmd = 1 then turn field on
+                       } else {
+                               // if field already on leave alone (affects timing otherwise)
+                               if (off) {
+                                       FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
+                                       LED_D_ON();
+                                       off = false;
+                               }
+                               // note we appear to take about 7us to switch over (or run the if statements/loop...)
+                               WaitUS(period_1-hack_cnt);
+                       }
+               }
+       } else { // old mode of cmd read using delay as off period
+               while(*command != '\0' && *command != ' ') {
+                       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+                       LED_D_OFF();
+                       WaitUS(delay_off);
+                       FpgaSendCommand(FPGA_CMD_SET_DIVISOR, sc->divisor);
+                       FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
+                       LED_D_ON();
+                       if(*(command++) == '0') {
+                               WaitUS(period_0);
+                       } else {
+                               WaitUS(period_1);
+                       }
+               }
                FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
                LED_D_OFF();
-               SpinDelayUs(delay_off);
-               if (at134khz)
-                       FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz
-               else
-                       FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
-
-               FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);
-               LED_D_ON();
-               if(*(command++) == '0')
-                       SpinDelayUs(period_0);
-               else
-                       SpinDelayUs(period_1);
+               WaitUS(delay_off);
+               FpgaSendCommand(FPGA_CMD_SET_DIVISOR, sc->divisor);
        }
-       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
-       LED_D_OFF();
-       SpinDelayUs(delay_off);
-       if (at134khz)
-               FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz
-       else
-               FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
 
-       FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
 
        // now do the read
-       DoAcquisition125k();
+       DoAcquisition_config(false, 0);
+
+       // Turn off antenna
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+       // tell client we are done
+       cmd_send(CMD_ACK,0,0,0,0,0);
 }
 
 /* blank r/w tag data stream
@@ -131,25 +143,23 @@ void ReadTItag(void)
        // when we read a TI tag we sample the zerocross line at 2Mhz
        // TI tags modulate a 1 as 16 cycles of 123.2Khz
        // TI tags modulate a 0 as 16 cycles of 134.2Khz
-       #define FSAMPLE 2000000
-       #define FREQLO 123200
-       #define FREQHI 134200
-
-       signed char *dest = (signed char *)BigBuf;
-       int n = sizeof(BigBuf);
-//     int *dest = GraphBuffer;
-//     int n = GraphTraceLen;
+ #define FSAMPLE 2000000
+ #define FREQLO 123200
+ #define FREQHI 134200
 
+       signed char *dest = (signed char *)BigBuf_get_addr();
+       uint16_t n = BigBuf_max_traceLen();
        // 128 bit shift register [shift3:shift2:shift1:shift0]
-       DWORD shift3 = 0, shift2 = 0, shift1 = 0, shift0 = 0;
+       uint32_t shift3 = 0, shift2 = 0, shift1 = 0, shift0 = 0;
 
        int i, cycles=0, samples=0;
        // how many sample points fit in 16 cycles of each frequency
-       DWORD sampleslo = (FSAMPLE<<4)/FREQLO, sampleshi = (FSAMPLE<<4)/FREQHI;
+       uint32_t sampleslo = (FSAMPLE<<4)/FREQLO, sampleshi = (FSAMPLE<<4)/FREQHI;
        // when to tell if we're close enough to one freq or another
-       DWORD threshold = (sampleslo - sampleshi + 1)>>1;
+       uint32_t threshold = (sampleslo - sampleshi + 1)>>1;
 
        // TI tags charge at 134.2Khz
+       FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
        FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz
 
        // Place FPGA in passthrough mode, in this mode the CROSS_LO line
@@ -174,10 +184,10 @@ void ReadTItag(void)
 
                                // TI bits are coming to us lsb first so shift them
                                // right through our 128 bit right shift register
-                         shift0 = (shift0>>1) | (shift1 << 31);
-                         shift1 = (shift1>>1) | (shift2 << 31);
-                         shift2 = (shift2>>1) | (shift3 << 31);
-                         shift3 >>= 1;
+                               shift0 = (shift0>>1) | (shift1 << 31);
+                               shift1 = (shift1>>1) | (shift2 << 31);
+                               shift2 = (shift2>>1) | (shift3 << 31);
+                               shift3 >>= 1;
 
                                // check if the cycles fall close to the number
                                // expected for either the low or high frequency
@@ -212,18 +222,18 @@ void ReadTItag(void)
        if (cycles!=0xF0B) {
                DbpString("Info: No valid tag detected.");
        } else {
-         // put 64 bit data into shift1 and shift0
-         shift0 = (shift0>>24) | (shift1 << 8);
-         shift1 = (shift1>>24) | (shift2 << 8);
+               // put 64 bit data into shift1 and shift0
+               shift0 = (shift0>>24) | (shift1 << 8);
+               shift1 = (shift1>>24) | (shift2 << 8);
 
                // align 16 bit crc into lower half of shift2
-         shift2 = ((shift2>>24) | (shift3 << 8)) & 0x0ffff;
+               shift2 = ((shift2>>24) | (shift3 << 8)) & 0x0ffff;
 
                // if r/w tag, check ident match
-               if ( shift3&(1<<15) ) {
+               if (shift3 & (1<<15) ) {
                        DbpString("Info: TI tag is rewriteable");
                        // only 15 bits compare, last bit of ident is not valid
-                       if ( ((shift3>>16)^shift0)&0x7fff ) {
+                       if (((shift3 >> 16) ^ shift0) & 0x7fff ) {
                                DbpString("Error: Ident mismatch!");
                        } else {
                                DbpString("Info: TI tag ident is valid");
@@ -236,9 +246,9 @@ void ReadTItag(void)
                // i'm 99% sure the crc algorithm is correct, but it may need to eat the
                // bytes in reverse or something
                // calculate CRC
-               DWORD crc=0;
+               uint32_t crc=0;
 
-               crc = update_crc16(crc, (shift0)&0xff);
+               crc = update_crc16(crc, (shift0)&0xff);
                crc = update_crc16(crc, (shift0>>8)&0xff);
                crc = update_crc16(crc, (shift0>>16)&0xff);
                crc = update_crc16(crc, (shift0>>24)&0xff);
@@ -248,7 +258,7 @@ void ReadTItag(void)
                crc = update_crc16(crc, (shift1>>24)&0xff);
 
                Dbprintf("Info: Tag data: %x%08x, crc=%x",
-                       (unsigned int)shift1, (unsigned int)shift0, (unsigned int)shift2 & 0xFFFF);
+                                (unsigned int)shift1, (unsigned int)shift0, (unsigned int)shift2 & 0xFFFF);
                if (crc != (shift2&0xffff)) {
                        Dbprintf("Error: CRC mismatch, expected %x", (unsigned int)crc);
                } else {
@@ -257,7 +267,7 @@ void ReadTItag(void)
        }
 }
 
-void WriteTIbyte(BYTE b)
+void WriteTIbyte(uint8_t b)
 {
        int i = 0;
 
@@ -286,11 +296,12 @@ void AcquireTiType(void)
 {
        int i, j, n;
        // tag transmission is <20ms, sampling at 2M gives us 40K samples max
-       // each sample is 1 bit stuffed into a DWORD so we need 1250 DWORDS
      #define TIBUFLEN 1250
+       // each sample is 1 bit stuffed into a uint32_t so we need 1250 uint32_t
+ #define TIBUFLEN 1250
 
        // clear buffer
-       memset(BigBuf,0,sizeof(BigBuf));
+       uint32_t *BigBuf = (uint32_t *)BigBuf_get_addr();
+       BigBuf_Clear_ext(false);
 
        // Set up the synchronous serial port
        AT91C_BASE_PIOA->PIO_PDR = GPIO_SSC_DIN;
@@ -338,7 +349,7 @@ void AcquireTiType(void)
        AT91C_BASE_PIOA->PIO_PDR = GPIO_SSC_DOUT;
        AT91C_BASE_PIOA->PIO_ASR = GPIO_SSC_DIN | GPIO_SSC_DOUT;
 
-       char *dest = (char *)BigBuf;
+       char *dest = (char *)BigBuf_get_addr();
        n = TIBUFLEN*32;
        // unpack buffer
        for (i=TIBUFLEN-1; i>=0; i--) {
@@ -355,10 +366,11 @@ void AcquireTiType(void)
 // arguments: 64bit data split into 32bit idhi:idlo and optional 16bit crc
 // if crc provided, it will be written with the data verbatim (even if bogus)
 // if not provided a valid crc will be computed from the data and written.
-void WriteTItag(DWORD idhi, DWORD idlo, WORD crc)
+void WriteTItag(uint32_t idhi, uint32_t idlo, uint16_t crc)
 {
+       FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
        if(crc == 0) {
-               crc = update_crc16(crc, (idlo)&0xff);
+               crc = update_crc16(crc, (idlo)&0xff);
                crc = update_crc16(crc, (idlo>>8)&0xff);
                crc = update_crc16(crc, (idlo>>16)&0xff);
                crc = update_crc16(crc, (idlo>>24)&0xff);
@@ -368,7 +380,7 @@ void WriteTItag(DWORD idhi, DWORD idlo, WORD crc)
                crc = update_crc16(crc, (idhi>>24)&0xff);
        }
        Dbprintf("Writing to tag: %x%08x, crc=%x",
-               (unsigned int) idhi, (unsigned int) idlo, crc);
+                       (unsigned int) idhi, (unsigned int) idlo, crc);
 
        // TI tags charge at 134.2Khz
        FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz
@@ -420,34 +432,43 @@ void WriteTItag(DWORD idhi, DWORD idlo, WORD crc)
        AcquireTiType();
 
        FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
-       DbpString("Now use tiread to check");
+       DbpString("Now use `lf ti read` to check");
 }
 
 void SimulateTagLowFrequency(int period, int gap, int ledcontrol)
 {
        int i;
-       BYTE *tab = (BYTE *)BigBuf;
+       uint8_t *tab = BigBuf_get_addr();
 
-       FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_SIMULATOR);
+       //note FpgaDownloadAndGo destroys the bigbuf so be sure this is called before now...
+       //FpgaDownloadAndGo(FPGA_BITSTREAM_LF);  
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_EDGE_DETECT);
 
        AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DOUT | GPIO_SSC_CLK;
 
        AT91C_BASE_PIOA->PIO_OER = GPIO_SSC_DOUT;
        AT91C_BASE_PIOA->PIO_ODR = GPIO_SSC_CLK;
 
-#define SHORT_COIL()   LOW(GPIO_SSC_DOUT)
-#define OPEN_COIL()            HIGH(GPIO_SSC_DOUT)
+ #define SHORT_COIL()   LOW(GPIO_SSC_DOUT)
+ #define OPEN_COIL()    HIGH(GPIO_SSC_DOUT)
 
        i = 0;
        for(;;) {
+               //wait until SSC_CLK goes HIGH
+               int ii = 0;
                while(!(AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_CLK)) {
-                       if(BUTTON_PRESS()) {
-                               DbpString("Stopped");
-                               return;
+                       //only check every 1000th time (usb_poll_validate_length on some systems was too slow)
+                       if ( ii == 1000 ) {
+                               if (BUTTON_PRESS() || usb_poll_validate_length() ) {
+                                       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+                                       DbpString("Stopped");
+                                       return;
+                               }
+                               ii=0;
                        }
                        WDT_HIT();
+                       ii++;
                }
-
                if (ledcontrol)
                        LED_D_ON();
 
@@ -458,242 +479,65 @@ void SimulateTagLowFrequency(int period, int gap, int ledcontrol)
 
                if (ledcontrol)
                        LED_D_OFF();
-
+               ii=0;
+               //wait until SSC_CLK goes LOW
                while(AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_CLK) {
-                       if(BUTTON_PRESS()) {
-                               DbpString("Stopped");
-                               return;
+                       //only check every 1000th time (usb_poll_validate_length on some systems was too slow)
+                       if ( ii == 1000 ) { 
+                               if (BUTTON_PRESS() || usb_poll_validate_length() ) {
+                                       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+                                       DbpString("Stopped");
+                                       return;
+                               }
+                               ii=0;
                        }
                        WDT_HIT();
+                       ii++;
                }
 
                i++;
                if(i == period) {
+
                        i = 0;
-                       if (gap) { 
+                       if (gap) {
                                SHORT_COIL();
                                SpinDelayUs(gap);
                        }
                }
+
        }
 }
 
-/* Provides a framework for bidirectional LF tag communication
- * Encoding is currently Hitag2, but the general idea can probably
- * be transferred to other encodings.
- * 
- * The new FPGA code will, for the LF simulator mode, give on SSC_FRAME
- * (PA15) a thresholded version of the signal from the ADC. Setting the
- * ADC path to the low frequency peak detection signal, will enable a
- * somewhat reasonable receiver for modulation on the carrier signal
- * that is generated by the reader. The signal is low when the reader
- * field is switched off, and high when the reader field is active. Due
- * to the way that the signal looks like, mostly only the rising edge is
- * useful, your mileage may vary.
- * 
- * Neat perk: PA15 can not only be used as a bit-banging GPIO, but is also
- * TIOA1, which can be used as the capture input for timer 1. This should
- * make it possible to measure the exact edge-to-edge time, without processor
- * intervention.
- * 
- * Arguments: divisor is the divisor to be sent to the FPGA (e.g. 95 for 125kHz)
- * t0 is the carrier frequency cycle duration in terms of MCK (384 for 125kHz)
- * 
- * The following defines are in carrier periods: 
- */
-#define HITAG_T_0_MIN 15 /* T[0] should be 18..22 */ 
-#define HITAG_T_1_MIN 24 /* T[1] should be 26..30 */
-#define HITAG_T_EOF   40 /* T_EOF should be > 36 */
-#define HITAG_T_WRESP 208 /* T_wresp should be 204..212 */
-
-static void hitag_handle_frame(int t0, int frame_len, char *frame);
-//#define DEBUG_RA_VALUES 1
 #define DEBUG_FRAME_CONTENTS 1
 void SimulateTagLowFrequencyBidir(int divisor, int t0)
 {
-#if DEBUG_RA_VALUES || DEBUG_FRAME_CONTENTS
-       int i = 0;
-#endif
-       char frame[10];
-       int frame_pos=0;
-       
-       DbpString("Starting Hitag2 emulator, press button to end");
-       hitag2_init();
-       
-       /* Set up simulator mode, frequency divisor which will drive the FPGA
-        * and analog mux selection.
-        */
-       FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_SIMULATOR);
-       FpgaSendCommand(FPGA_CMD_SET_DIVISOR, divisor);
-       SetAdcMuxFor(GPIO_MUXSEL_LOPKD);
-       RELAY_OFF();
-       
-       /* Set up Timer 1:
-        * Capture mode, timer source MCK/2 (TIMER_CLOCK1), TIOA is external trigger,
-        * external trigger rising edge, load RA on rising edge of TIOA, load RB on rising
-        * edge of TIOA. Assign PA15 to TIOA1 (peripheral B)
-        */
-       
-       AT91C_BASE_PMC->PMC_PCER = (1 << AT91C_ID_TC1);
-       AT91C_BASE_PIOA->PIO_BSR = GPIO_SSC_FRAME;
-       AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKDIS;
-       AT91C_BASE_TC1->TC_CMR =        TC_CMR_TCCLKS_TIMER_CLOCK1 |
-                                                               AT91C_TC_ETRGEDG_RISING |
-                                                               AT91C_TC_ABETRG |
-                                                               AT91C_TC_LDRA_RISING |
-                                                               AT91C_TC_LDRB_RISING;
-       AT91C_BASE_TC1->TC_CCR =        AT91C_TC_CLKEN |
-                                                               AT91C_TC_SWTRG;
-       
-       /* calculate the new value for the carrier period in terms of TC1 values */
-       t0 = t0/2;
-       
-       int overflow = 0;
-       while(!BUTTON_PRESS()) {
-               WDT_HIT();
-               if(AT91C_BASE_TC1->TC_SR & AT91C_TC_LDRAS) {
-                       int ra = AT91C_BASE_TC1->TC_RA;
-                       if((ra > t0*HITAG_T_EOF) | overflow) ra = t0*HITAG_T_EOF+1;
-#if DEBUG_RA_VALUES
-                       if(ra > 255 || overflow) ra = 255;
-                       ((char*)BigBuf)[i] = ra;
-                       i = (i+1) % 8000;
-#endif
-                       
-                       if(overflow || (ra > t0*HITAG_T_EOF) || (ra < t0*HITAG_T_0_MIN)) {
-                               /* Ignore */
-                       } else if(ra >= t0*HITAG_T_1_MIN ) {
-                               /* '1' bit */
-                               if(frame_pos < 8*sizeof(frame)) {
-                                       frame[frame_pos / 8] |= 1<<( 7-(frame_pos%8) );
-                                       frame_pos++;
-                               }
-                       } else if(ra >= t0*HITAG_T_0_MIN) {
-                               /* '0' bit */
-                               if(frame_pos < 8*sizeof(frame)) {
-                                       frame[frame_pos / 8] |= 0<<( 7-(frame_pos%8) );
-                                       frame_pos++;
-                               }
-                       }
-                       
-                       overflow = 0;
-                       LED_D_ON();
-               } else {
-                       if(AT91C_BASE_TC1->TC_CV > t0*HITAG_T_EOF) {
-                               /* Minor nuisance: In Capture mode, the timer can not be
-                                * stopped by a Compare C. There's no way to stop the clock
-                                * in software, so we'll just have to note the fact that an
-                                * overflow happened and the next loaded timer value might
-                                * have wrapped. Also, this marks the end of frame, and the
-                                * still running counter can be used to determine the correct
-                                * time for the start of the reply.
-                                */ 
-                               overflow = 1;
-                               
-                               if(frame_pos > 0) {
-                                       /* Have a frame, do something with it */
-#if DEBUG_FRAME_CONTENTS
-                                       ((char*)BigBuf)[i++] = frame_pos;
-                                       memcpy( ((char*)BigBuf)+i, frame, 7);
-                                       i+=7;
-                                       i = i % sizeof(BigBuf);
-#endif
-                                       hitag_handle_frame(t0, frame_pos, frame);
-                                       memset(frame, 0, sizeof(frame));
-                               }
-                               frame_pos = 0;
-
-                       }
-                       LED_D_OFF();
-               }
-       }
-       DbpString("All done");
-}
-
-static void hitag_send_bit(int t0, int bit) {
-       if(bit == 1) {
-               /* Manchester: Loaded, then unloaded */
-               LED_A_ON();
-               SHORT_COIL();
-               while(AT91C_BASE_TC1->TC_CV < t0*15);
-               OPEN_COIL();
-               while(AT91C_BASE_TC1->TC_CV < t0*31);
-               LED_A_OFF();
-       } else if(bit == 0) {
-               /* Manchester: Unloaded, then loaded */
-               LED_B_ON();
-               OPEN_COIL();
-               while(AT91C_BASE_TC1->TC_CV < t0*15);
-               SHORT_COIL();
-               while(AT91C_BASE_TC1->TC_CV < t0*31);
-               LED_B_OFF();
-       }
-       AT91C_BASE_TC1->TC_CCR = AT91C_TC_SWTRG; /* Reset clock for the next bit */
-       
-}
-static void hitag_send_frame(int t0, int frame_len, const char const * frame, int fdt)
-{
-       OPEN_COIL();
-       AT91C_BASE_PIOA->PIO_OER = GPIO_SSC_DOUT;
-       
-       /* Wait for HITAG_T_WRESP carrier periods after the last reader bit,
-        * not that since the clock counts since the rising edge, but T_wresp is
-        * with respect to the falling edge, we need to wait actually (T_wresp - T_g)
-        * periods. The gap time T_g varies (4..10).
-        */
-       while(AT91C_BASE_TC1->TC_CV < t0*(fdt-8));
-
-       int saved_cmr = AT91C_BASE_TC1->TC_CMR;
-       AT91C_BASE_TC1->TC_CMR &= ~AT91C_TC_ETRGEDG; /* Disable external trigger for the clock */
-       AT91C_BASE_TC1->TC_CCR = AT91C_TC_SWTRG; /* Reset the clock and use it for response timing */
-       
-       int i;
-       for(i=0; i<5; i++)
-               hitag_send_bit(t0, 1); /* Start of frame */
-       
-       for(i=0; i<frame_len; i++) {
-               hitag_send_bit(t0, !!(frame[i/ 8] & (1<<( 7-(i%8) ))) );
-       }
-       
-       OPEN_COIL();
-       AT91C_BASE_TC1->TC_CMR = saved_cmr;
 }
 
-/* Callback structure to cleanly separate tag emulation code from the radio layer. */
-static int hitag_cb(const char* response_data, const int response_length, const int fdt, void *cb_cookie)
-{
-       hitag_send_frame(*(int*)cb_cookie, response_length, response_data, fdt);
-       return 0;
-}
-/* Frame length in bits, frame contents in MSBit first format */
-static void hitag_handle_frame(int t0, int frame_len, char *frame)
+// compose fc/8 fc/10 waveform (FSK2)
+static void fc(int c, int *n)
 {
-       hitag2_handle_command(frame, frame_len, hitag_cb, &t0);
-}
-
-// compose fc/8 fc/10 waveform
-static void fc(int c, int *n) {
-       BYTE *dest = (BYTE *)BigBuf;
+       uint8_t *dest = BigBuf_get_addr();
        int idx;
 
        // for when we want an fc8 pattern every 4 logical bits
        if(c==0) {
                dest[((*n)++)]=1;
                dest[((*n)++)]=1;
-               dest[((*n)++)]=0;
-               dest[((*n)++)]=0;
+               dest[((*n)++)]=1;
+               dest[((*n)++)]=1;
                dest[((*n)++)]=0;
                dest[((*n)++)]=0;
                dest[((*n)++)]=0;
                dest[((*n)++)]=0;
        }
-       //      an fc/8  encoded bit is a bit pattern of  11000000  x6 = 48 samples
+
+       //      an fc/8  encoded bit is a bit pattern of  11110000  x6 = 48 samples
        if(c==8) {
                for (idx=0; idx<6; idx++) {
                        dest[((*n)++)]=1;
                        dest[((*n)++)]=1;
-                       dest[((*n)++)]=0;
-                       dest[((*n)++)]=0;
+                       dest[((*n)++)]=1;
+                       dest[((*n)++)]=1;
                        dest[((*n)++)]=0;
                        dest[((*n)++)]=0;
                        dest[((*n)++)]=0;
@@ -701,9 +545,11 @@ static void fc(int c, int *n) {
                }
        }
 
-       //      an fc/10 encoded bit is a bit pattern of 1110000000 x5 = 50 samples
+       //      an fc/10 encoded bit is a bit pattern of 1111100000 x5 = 50 samples
        if(c==10) {
                for (idx=0; idx<5; idx++) {
+                       dest[((*n)++)]=1;
+                       dest[((*n)++)]=1;
                        dest[((*n)++)]=1;
                        dest[((*n)++)]=1;
                        dest[((*n)++)]=1;
@@ -712,15 +558,43 @@ static void fc(int c, int *n) {
                        dest[((*n)++)]=0;
                        dest[((*n)++)]=0;
                        dest[((*n)++)]=0;
-                       dest[((*n)++)]=0;
-                       dest[((*n)++)]=0;
                }
        }
 }
+// compose fc/X fc/Y waveform (FSKx)
+static void fcAll(uint8_t fc, int *n, uint8_t clock, uint16_t *modCnt) 
+{
+       uint8_t *dest = BigBuf_get_addr();
+       uint8_t halfFC = fc/2;
+       uint8_t wavesPerClock = clock/fc;
+       uint8_t mod = clock % fc;    //modifier
+       uint8_t modAdj = fc/mod;     //how often to apply modifier
+       bool modAdjOk = !(fc % mod); //if (fc % mod==0) modAdjOk=true;
+       // loop through clock - step field clock
+       for (uint8_t idx=0; idx < wavesPerClock; idx++){
+               // put 1/2 FC length 1's and 1/2 0's per field clock wave (to create the wave)
+               memset(dest+(*n), 0, fc-halfFC);  //in case of odd number use extra here
+               memset(dest+(*n)+(fc-halfFC), 1, halfFC);
+               *n += fc;
+       }
+       if (mod>0) (*modCnt)++;
+       if ((mod>0) && modAdjOk){  //fsk2 
+               if ((*modCnt % modAdj) == 0){ //if 4th 8 length wave in a rf/50 add extra 8 length wave
+                       memset(dest+(*n), 0, fc-halfFC);
+                       memset(dest+(*n)+(fc-halfFC), 1, halfFC);
+                       *n += fc;
+               }
+       }
+       if (mod>0 && !modAdjOk){  //fsk1
+               memset(dest+(*n), 0, mod-(mod/2));
+               memset(dest+(*n)+(mod-(mod/2)), 1, mod/2);
+               *n += mod;
+       }
+}
 
 // prepare a waveform pattern in the buffer based on the ID given then
 // simulate a HID tag until the button is pressed
-void CmdHIDsimTAG(int hi, int lo, int ledcontrol)
+void CmdHIDsimTAG(int hi2, int hi, int lo, int ledcontrol)
 {
        int n=0, i=0;
        /*
@@ -733,25 +607,50 @@ void CmdHIDsimTAG(int hi, int lo, int ledcontrol)
         nor 1 bits, they are special patterns (a = set of 12 fc8 and b = set of 10 fc10)
        */
 
-       if (hi>0xFFF) {
-               DbpString("Tags can only have 44 bits.");
+       if (hi2>0x0FFFFFFF) {
+               DbpString("Tags can only have 44 or 84 bits. - USE lf simfsk for larger tags");
                return;
        }
+       // set LF so we don't kill the bigbuf we are setting with simulation data.
+       FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
+
        fc(0,&n);
        // special start of frame marker containing invalid bit sequences
-       fc(8,  &n);     fc(8,  &n);     // invalid
+       fc(8,  &n);     fc(8,  &n); // invalid
        fc(8,  &n);     fc(10, &n); // logical 0
        fc(10, &n);     fc(10, &n); // invalid
        fc(8,  &n);     fc(10, &n); // logical 0
 
        WDT_HIT();
-       // manchester encode bits 43 to 32
-       for (i=11; i>=0; i--) {
-               if ((i%4)==3) fc(0,&n);
-               if ((hi>>i)&1) {
-                       fc(10, &n);     fc(8,  &n);             // low-high transition
-               } else {
-                       fc(8,  &n);     fc(10, &n);             // high-low transition
+       if (hi2 > 0 || hi > 0xFFF){
+               // manchester encode bits 91 to 64 (91-84 are part of the header)
+               for (i=27; i>=0; i--) {
+                       if ((i%4)==3) fc(0,&n);
+                       if ((hi2>>i)&1) {
+                               fc(10, &n); fc(8,  &n);         // low-high transition
+                       } else {
+                               fc(8,  &n); fc(10, &n);         // high-low transition
+                       }
+               }
+               WDT_HIT();
+               // manchester encode bits 63 to 32
+               for (i=31; i>=0; i--) {
+                       if ((i%4)==3) fc(0,&n);
+                       if ((hi>>i)&1) {
+                               fc(10, &n); fc(8,  &n);         // low-high transition
+                       } else {
+                               fc(8,  &n); fc(10, &n);         // high-low transition
+                       }
+               }
+       } else {
+               // manchester encode bits 43 to 32
+               for (i=11; i>=0; i--) {
+                       if ((i%4)==3) fc(0,&n);
+                       if ((hi>>i)&1) {
+                               fc(10, &n); fc(8,  &n);         // low-high transition
+                       } else {
+                               fc(8,  &n); fc(10, &n);         // high-low transition
+                       }
                }
        }
 
@@ -760,9 +659,9 @@ void CmdHIDsimTAG(int hi, int lo, int ledcontrol)
        for (i=31; i>=0; i--) {
                if ((i%4)==3) fc(0,&n);
                if ((lo>>i)&1) {
-                       fc(10, &n);     fc(8,  &n);             // low-high transition
+                       fc(10, &n); fc(8,  &n);         // low-high transition
                } else {
-                       fc(8,  &n);     fc(10, &n);             // high-low transition
+                       fc(8,  &n); fc(10, &n);         // high-low transition
                }
        }
 
@@ -774,198 +673,1415 @@ void CmdHIDsimTAG(int hi, int lo, int ledcontrol)
                LED_A_OFF();
 }
 
-
-// loop to capture raw HID waveform then FSK demodulate the TAG ID from it
-void CmdHIDdemodFSK(int findone, int *high, int *low, int ledcontrol)
+// prepare a waveform pattern in the buffer based on the ID given then
+// simulate a FSK tag until the button is pressed
+// arg1 contains fcHigh and fcLow, arg2 contains invert and clock
+void CmdFSKsimTAG(uint16_t arg1, uint16_t arg2, size_t size, uint8_t *BitStream)
 {
-       BYTE *dest = (BYTE *)BigBuf;
-       int m=0, n=0, i=0, idx=0, found=0, lastval=0;
-       DWORD hi=0, lo=0;
+       int ledcontrol=1;
+       int n=0, i=0;
+       uint8_t fcHigh = arg1 >> 8;
+       uint8_t fcLow = arg1 & 0xFF;
+       uint16_t modCnt = 0;
+       uint8_t clk = arg2 & 0xFF;
+       uint8_t invert = (arg2 >> 8) & 1;
+
+       // set LF so we don't kill the bigbuf we are setting with simulation data.
+       FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
+
+       for (i=0; i<size; i++){
+               if (BitStream[i] == invert){
+                       fcAll(fcLow, &n, clk, &modCnt);
+               } else {
+                       fcAll(fcHigh, &n, clk, &modCnt);
+               }
+       }
+       Dbprintf("Simulating with fcHigh: %d, fcLow: %d, clk: %d, invert: %d, n: %d",fcHigh, fcLow, clk, invert, n);
+       /*Dbprintf("DEBUG: First 32:");
+       uint8_t *dest = BigBuf_get_addr();
+       i=0;
+       Dbprintf("%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d", dest[i],dest[i+1],dest[i+2],dest[i+3],dest[i+4],dest[i+5],dest[i+6],dest[i+7],dest[i+8],dest[i+9],dest[i+10],dest[i+11],dest[i+12],dest[i+13],dest[i+14],dest[i+15]);
+       i+=16;
+       Dbprintf("%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d", dest[i],dest[i+1],dest[i+2],dest[i+3],dest[i+4],dest[i+5],dest[i+6],dest[i+7],dest[i+8],dest[i+9],dest[i+10],dest[i+11],dest[i+12],dest[i+13],dest[i+14],dest[i+15]);
+       */
+       if (ledcontrol)
+               LED_A_ON();
 
-       FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
-       FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);
+       SimulateTagLowFrequency(n, 0, ledcontrol);
 
-       // Connect the A/D to the peak-detected low-frequency path.
-       SetAdcMuxFor(GPIO_MUXSEL_LOPKD);
+       if (ledcontrol)
+               LED_A_OFF();
+}
 
-       // Give it a bit of time for the resonant antenna to settle.
-       SpinDelay(50);
+// compose ask waveform for one bit(ASK)
+static void askSimBit(uint8_t c, int *n, uint8_t clock, uint8_t manchester)
+{
+       uint8_t *dest = BigBuf_get_addr();
+       uint8_t halfClk = clock/2;
+       // c = current bit 1 or 0
+       if (manchester==1){
+               memset(dest+(*n), c, halfClk);
+               memset(dest+(*n) + halfClk, c^1, halfClk);
+       } else {
+               memset(dest+(*n), c, clock);
+       }
+       *n += clock;
+}
 
-       // Now set up the SSC to get the ADC samples that are now streaming at us.
-       FpgaSetupSsc();
+static void biphaseSimBit(uint8_t c, int *n, uint8_t clock, uint8_t *phase)
+{
+       uint8_t *dest = BigBuf_get_addr();
+       uint8_t halfClk = clock/2;
+       if (c){
+               memset(dest+(*n), c ^ 1 ^ *phase, halfClk);
+               memset(dest+(*n) + halfClk, c ^ *phase, halfClk);
+       } else {
+               memset(dest+(*n), c ^ *phase, clock);
+               *phase ^= 1;
+       }
+       *n += clock;
+}
 
-       for(;;) {
-               WDT_HIT();
-               if (ledcontrol)
-                       LED_A_ON();
-               if(BUTTON_PRESS()) {
-                       DbpString("Stopped");
-                       if (ledcontrol)
-                               LED_A_OFF();
-                       return;
-               }
+static void stAskSimBit(int *n, uint8_t clock) {
+       uint8_t *dest = BigBuf_get_addr();
+       uint8_t halfClk = clock/2;
+       //ST = .5 high .5 low 1.5 high .5 low 1 high    
+       memset(dest+(*n), 1, halfClk);
+       memset(dest+(*n) + halfClk, 0, halfClk);
+       memset(dest+(*n) + clock, 1, clock + halfClk);
+       memset(dest+(*n) + clock*2 + halfClk, 0, halfClk);
+       memset(dest+(*n) + clock*3, 1, clock);
+       *n += clock*4;
+}
 
-               i = 0;
-               m = sizeof(BigBuf);
-               memset(dest,128,m);
-               for(;;) {
-                       if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
-                               AT91C_BASE_SSC->SSC_THR = 0x43;
-                               if (ledcontrol)
-                                       LED_D_ON();
+// args clock, ask/man or askraw, invert, transmission separator
+void CmdASKsimTag(uint16_t arg1, uint16_t arg2, size_t size, uint8_t *BitStream)
+{
+       int ledcontrol = 1;
+       int n=0, i=0;
+       uint8_t clk = (arg1 >> 8) & 0xFF;
+       uint8_t encoding = arg1 & 0xFF;
+       uint8_t separator = arg2 & 1;
+       uint8_t invert = (arg2 >> 8) & 1;
+
+       // set LF so we don't kill the bigbuf we are setting with simulation data.
+       FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
+
+       if (encoding==2){  //biphase
+               uint8_t phase=0;
+               for (i=0; i<size; i++){
+                       biphaseSimBit(BitStream[i]^invert, &n, clk, &phase);
+               }
+               if (phase==1) { //run a second set inverted to keep phase in check
+                       for (i=0; i<size; i++){
+                               biphaseSimBit(BitStream[i]^invert, &n, clk, &phase);
                        }
-                       if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
-                               dest[i] = (BYTE)AT91C_BASE_SSC->SSC_RHR;
-                               // we don't care about actual value, only if it's more or less than a
-                               // threshold essentially we capture zero crossings for later analysis
-                               if(dest[i] < 127) dest[i] = 0; else dest[i] = 1;
-                               i++;
-                               if (ledcontrol)
-                                       LED_D_OFF();
-                               if(i >= m) {
-                                       break;
-                               }
+               }
+       } else {  // ask/manchester || ask/raw
+               for (i=0; i<size; i++){
+                       askSimBit(BitStream[i]^invert, &n, clk, encoding);
+               }
+               if (encoding==0 && BitStream[0]==BitStream[size-1]){ //run a second set inverted (for ask/raw || biphase phase)
+                       for (i=0; i<size; i++){
+                               askSimBit(BitStream[i]^invert^1, &n, clk, encoding);
                        }
                }
+       }
+       if (separator==1 && encoding == 1)
+               stAskSimBit(&n, clk);
+       else if (separator==1)
+               Dbprintf("sorry but separator option not yet available");
+
+       Dbprintf("Simulating with clk: %d, invert: %d, encoding: %d, separator: %d, n: %d",clk, invert, encoding, separator, n);
+       //DEBUG
+       //Dbprintf("First 32:");
+       //uint8_t *dest = BigBuf_get_addr();
+       //i=0;
+       //Dbprintf("%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d", dest[i],dest[i+1],dest[i+2],dest[i+3],dest[i+4],dest[i+5],dest[i+6],dest[i+7],dest[i+8],dest[i+9],dest[i+10],dest[i+11],dest[i+12],dest[i+13],dest[i+14],dest[i+15]);
+       //i+=16;
+       //Dbprintf("%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d", dest[i],dest[i+1],dest[i+2],dest[i+3],dest[i+4],dest[i+5],dest[i+6],dest[i+7],dest[i+8],dest[i+9],dest[i+10],dest[i+11],dest[i+12],dest[i+13],dest[i+14],dest[i+15]);
+       
+       if (ledcontrol) LED_A_ON();
+       SimulateTagLowFrequency(n, 0, ledcontrol);
+       if (ledcontrol) LED_A_OFF();
+}
 
-               // FSK demodulator
+//carrier can be 2,4 or 8
+static void pskSimBit(uint8_t waveLen, int *n, uint8_t clk, uint8_t *curPhase, bool phaseChg)
+{
+       uint8_t *dest = BigBuf_get_addr();
+       uint8_t halfWave = waveLen/2;
+       //uint8_t idx;
+       int i = 0;
+       if (phaseChg){
+               // write phase change
+               memset(dest+(*n), *curPhase^1, halfWave);
+               memset(dest+(*n) + halfWave, *curPhase, halfWave);
+               *n += waveLen;
+               *curPhase ^= 1;
+               i += waveLen;
+       }
+       //write each normal clock wave for the clock duration
+       for (; i < clk; i+=waveLen){
+               memset(dest+(*n), *curPhase, halfWave);
+               memset(dest+(*n) + halfWave, *curPhase^1, halfWave);
+               *n += waveLen;
+       }
+}
 
-               // sync to first lo-hi transition
-               for( idx=1; idx<m; idx++) {
-                       if (dest[idx-1]<dest[idx])
-                               lastval=idx;
-                               break;
+// args clock, carrier, invert,
+void CmdPSKsimTag(uint16_t arg1, uint16_t arg2, size_t size, uint8_t *BitStream)
+{
+       int ledcontrol=1;
+       int n=0, i=0;
+       uint8_t clk = arg1 >> 8;
+       uint8_t carrier = arg1 & 0xFF;
+       uint8_t invert = arg2 & 0xFF;
+       uint8_t curPhase = 0;
+       // set LF so we don't kill the bigbuf we are setting with simulation data.
+       FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
+
+       for (i=0; i<size; i++){
+               if (BitStream[i] == curPhase){
+                       pskSimBit(carrier, &n, clk, &curPhase, false);
+               } else {
+                       pskSimBit(carrier, &n, clk, &curPhase, true);
                }
-               WDT_HIT();
-
-               // count cycles between consecutive lo-hi transitions, there should be either 8 (fc/8)
-               // or 10 (fc/10) cycles but in practice due to noise etc we may end up with with anywhere
-               // between 7 to 11 cycles so fuzz it by treat anything <9 as 8 and anything else as 10
-               for( i=0; idx<m; idx++) {
-                       if (dest[idx-1]<dest[idx]) {
-                               dest[i]=idx-lastval;
-                               if (dest[i] <= 8) {
-                                               dest[i]=1;
-                               } else {
-                                               dest[i]=0;
-                               }
+       }
+       Dbprintf("Simulating with Carrier: %d, clk: %d, invert: %d, n: %d",carrier, clk, invert, n);
+       //Dbprintf("DEBUG: First 32:");
+       //uint8_t *dest = BigBuf_get_addr();
+       //i=0;
+       //Dbprintf("%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d", dest[i],dest[i+1],dest[i+2],dest[i+3],dest[i+4],dest[i+5],dest[i+6],dest[i+7],dest[i+8],dest[i+9],dest[i+10],dest[i+11],dest[i+12],dest[i+13],dest[i+14],dest[i+15]);
+       //i+=16;
+       //Dbprintf("%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d", dest[i],dest[i+1],dest[i+2],dest[i+3],dest[i+4],dest[i+5],dest[i+6],dest[i+7],dest[i+8],dest[i+9],dest[i+10],dest[i+11],dest[i+12],dest[i+13],dest[i+14],dest[i+15]);
+                  
+       if (ledcontrol) LED_A_ON();
+       SimulateTagLowFrequency(n, 0, ledcontrol);
+       if (ledcontrol) LED_A_OFF();
+}
 
-                               lastval=idx;
-                               i++;
-                       }
-               }
-               m=i;
+// loop to get raw HID waveform then FSK demodulate the TAG ID from it
+void CmdHIDdemodFSK(int findone, int *high2, int *high, int *low, int ledcontrol)
+{
+       uint8_t *dest = BigBuf_get_addr();
+       //const size_t sizeOfBigBuff = BigBuf_max_traceLen();
+       size_t size; 
+       uint32_t hi2=0, hi=0, lo=0;
+       int idx=0;
+       int dummyIdx = 0;
+       // Configure to go in 125Khz listen mode
+       LFSetupFPGAForADC(95, true);
+
+       //clear read buffer
+       BigBuf_Clear_keep_EM();
+
+       while(!BUTTON_PRESS() && !usb_poll_validate_length()) {
                WDT_HIT();
+               if (ledcontrol) LED_A_ON();
 
-               // we now have a set of cycle counts, loop over previous results and aggregate data into bit patterns
-               lastval=dest[0];
-               idx=0;
-               i=0;
-               n=0;
-               for( idx=0; idx<m; idx++) {
-                       if (dest[idx]==lastval) {
-                               n++;
-                       } else {
-                               // a bit time is five fc/10 or six fc/8 cycles so figure out how many bits a pattern width represents,
-                               // an extra fc/8 pattern preceeds every 4 bits (about 200 cycles) just to complicate things but it gets
-                               // swallowed up by rounding
-                               // expected results are 1 or 2 bits, any more and it's an invalid manchester encoding
-                               // special start of frame markers use invalid manchester states (no transitions) by using sequences
-                               // like 111000
-                               if (dest[idx-1]) {
-                                       n=(n+1)/6;                      // fc/8 in sets of 6
-                               } else {
-                                       n=(n+1)/5;                      // fc/10 in sets of 5
+               DoAcquisition_default(-1,true);
+               // FSK demodulator
+               //size = sizeOfBigBuff;  //variable size will change after demod so re initialize it before use
+               size = 50*128*2; //big enough to catch 2 sequences of largest format
+               idx = HIDdemodFSK(dest, &size, &hi2, &hi, &lo, &dummyIdx);
+               
+               if (idx>0 && lo>0 && (size==96 || size==192)){
+                       uint8_t bitlen = 0;
+                       uint32_t fc = 0;
+                       uint32_t cardnum = 0;
+                       bool decoded = false;
+
+                       // go over previously decoded manchester data and decode into usable tag ID
+                       if ((hi2 & 0x000FFFF) != 0){ //extra large HID tags  88/192 bits
+                               uint32_t bp = hi2 & 0x000FFFFF;
+                               bitlen = 63;
+                               while (bp > 0) {
+                                       bp = bp >> 1;
+                                       bitlen++;
                                }
-                               switch (n) {                    // stuff appropriate bits in buffer
-                                       case 0:
-                                       case 1: // one bit
-                                               dest[i++]=dest[idx-1];
-                                               break;
-                                       case 2: // two bits
-                                               dest[i++]=dest[idx-1];
-                                               dest[i++]=dest[idx-1];
-                                               break;
-                                       case 3: // 3 bit start of frame markers
-                                               dest[i++]=dest[idx-1];
-                                               dest[i++]=dest[idx-1];
-                                               dest[i++]=dest[idx-1];
-                                               break;
-                                       // When a logic 0 is immediately followed by the start of the next transmisson
-                                       // (special pattern) a pattern of 4 bit duration lengths is created.
-                                       case 4:
-                                               dest[i++]=dest[idx-1];
-                                               dest[i++]=dest[idx-1];
-                                               dest[i++]=dest[idx-1];
-                                               dest[i++]=dest[idx-1];
-                                               break;
-                                       default:        // this shouldn't happen, don't stuff any bits
-                                               break;
+                       } else if ((hi >> 6) > 0) {
+                               uint32_t bp = hi;
+                               bitlen = 31;
+                               while (bp > 0) {
+                                       bp = bp >> 1;
+                                       bitlen++;
                                }
-                               n=0;
-                               lastval=dest[idx];
+                       } else if (((hi >> 5) & 1) == 0) {
+                               bitlen = 37;
+                       } else if ((hi & 0x0000001F) > 0 ) {
+                               uint32_t bp = (hi & 0x0000001F);
+                               bitlen = 31;
+                               while (bp > 0) {
+                                       bp = bp >> 1;
+                                       bitlen++;
+                               }
+                       } else {
+                               uint32_t bp = lo;
+                               bitlen = 0;
+                               while (bp > 0) {
+                                       bp = bp >> 1;
+                                       bitlen++;
+                               }
+                       }
+                       switch (bitlen){
+                               case 26:
+                                       cardnum = (lo>>1)&0xFFFF;
+                                       fc = (lo>>17)&0xFF;
+                                       decoded = true;
+                                       break;
+                               case 35:
+                                       cardnum = (lo>>1)&0xFFFFF;
+                                       fc = ((hi&1)<<11)|(lo>>21);
+                                       decoded = true;
+                                       break;
+                       }
+                               
+                       if (hi2 != 0) //extra large HID tags  88/192 bits
+                               Dbprintf("TAG ID: %x%08x%08x (%d)",
+                                       (unsigned int) hi2, (unsigned int) hi, (unsigned int) lo, (unsigned int) (lo>>1) & 0xFFFF);
+                       else 
+                               Dbprintf("TAG ID: %x%08x (%d)",
+                                       (unsigned int) hi, (unsigned int) lo, (unsigned int) (lo>>1) & 0xFFFF);
+                       
+                       if (decoded)
+                               Dbprintf("Format Len: %dbits - FC: %d - Card: %d",
+                                       (unsigned int) bitlen, (unsigned int) fc, (unsigned int) cardnum);
+
+                       if (findone){
+                               if (ledcontrol) LED_A_OFF();
+                               *high2 = hi2;
+                               *high = hi;
+                               *low = lo;
+                               break;
                        }
+                       // reset
                }
-               m=i;
+               hi2 = hi = lo = idx = 0;
                WDT_HIT();
+       }
 
-               // final loop, go over previously decoded manchester data and decode into usable tag ID
-               // 111000 bit pattern represent start of frame, 01 pattern represents a 1 and 10 represents a 0
-               for( idx=0; idx<m-6; idx++) {
-                       // search for a start of frame marker
-                       if ( dest[idx] && dest[idx+1] && dest[idx+2] && (!dest[idx+3]) && (!dest[idx+4]) && (!dest[idx+5]) )
-                       {
-                               found=1;
-                               idx+=6;
-                               if (found && (hi|lo)) {
-                                       Dbprintf("TAG ID: %x%08x (%d)",
-                                               (unsigned int) hi, (unsigned int) lo, (unsigned int) (lo>>1) & 0xFFFF);
-                                       /* if we're only looking for one tag */
-                                       if (findone)
-                                       {
-                                               *high = hi;
-                                               *low = lo;
-                                               return;
-                                       }
-                                       hi=0;
-                                       lo=0;
-                                       found=0;
-                               }
-                       }
-                       if (found) {
-                               if (dest[idx] && (!dest[idx+1]) ) {
-                                       hi=(hi<<1)|(lo>>31);
-                                       lo=(lo<<1)|0;
-                               } else if ( (!dest[idx]) && dest[idx+1]) {
-                                       hi=(hi<<1)|(lo>>31);
-                                       lo=(lo<<1)|1;
-                               } else {
-                                       found=0;
-                                       hi=0;
-                                       lo=0;
-                               }
-                               idx++;
-                       }
-                       if ( dest[idx] && dest[idx+1] && dest[idx+2] && (!dest[idx+3]) && (!dest[idx+4]) && (!dest[idx+5]) )
-                       {
-                               found=1;
-                               idx+=6;
-                               if (found && (hi|lo)) {
-                                       Dbprintf("TAG ID: %x%08x (%d)",
-                                               (unsigned int) hi, (unsigned int) lo, (unsigned int) (lo>>1) & 0xFFFF);
-                                       /* if we're only looking for one tag */
-                                       if (findone)
-                                       {
-                                               *high = hi;
-                                               *low = lo;
-                                               return;
-                                       }
-                                       hi=0;
-                                       lo=0;
-                                       found=0;
-                               }
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+       DbpString("Stopped");
+       if (ledcontrol) LED_A_OFF();
+}
+
+// loop to get raw HID waveform then FSK demodulate the TAG ID from it
+void CmdAWIDdemodFSK(int findone, int *high, int *low, int ledcontrol)
+{
+       uint8_t *dest = BigBuf_get_addr();
+       size_t size; 
+       int idx=0, dummyIdx=0;
+       //clear read buffer
+       BigBuf_Clear_keep_EM();
+       // Configure to go in 125Khz listen mode
+       LFSetupFPGAForADC(95, true);
+
+       while(!BUTTON_PRESS() && !usb_poll_validate_length()) {
+
+               WDT_HIT();
+               if (ledcontrol) LED_A_ON();
+
+               DoAcquisition_default(-1,true);
+               // FSK demodulator
+               size = 50*128*2; //big enough to catch 2 sequences of largest format
+               idx = AWIDdemodFSK(dest, &size, &dummyIdx);
+               
+               if (idx<=0 || size!=96) continue;
+               // Index map
+               // 0            10            20            30              40            50              60
+               // |            |             |             |               |             |               |
+               // 01234567 890 1 234 5 678 9 012 3 456 7 890 1 234 5 678 9 012 3 456 7 890 1 234 5 678 9 012 3 - to 96
+               // -----------------------------------------------------------------------------
+               // 00000001 000 1 110 1 101 1 011 1 101 1 010 0 000 1 000 1 010 0 001 0 110 1 100 0 000 1 000 1
+               // premable bbb o bbb o bbw o fff o fff o ffc o ccc o ccc o ccc o ccc o ccc o wxx o xxx o xxx o - to 96
+               //          |---26 bit---|    |-----117----||-------------142-------------|
+               // b = format bit len, o = odd parity of last 3 bits
+               // f = facility code, c = card number
+               // w = wiegand parity
+               // (26 bit format shown)
+
+               //get raw ID before removing parities
+               uint32_t rawLo = bytebits_to_byte(dest+idx+64,32);
+               uint32_t rawHi = bytebits_to_byte(dest+idx+32,32);
+               uint32_t rawHi2 = bytebits_to_byte(dest+idx,32);
+
+               size = removeParity(dest, idx+8, 4, 1, 88);
+               if (size != 66) continue;
+               // ok valid card found!
+
+               // Index map
+               // 0           10         20        30          40        50        60
+               // |           |          |         |           |         |         |
+               // 01234567 8 90123456 7890123456789012 3 456789012345678901234567890123456
+               // -----------------------------------------------------------------------------
+               // 00011010 1 01110101 0000000010001110 1 000000000000000000000000000000000
+               // bbbbbbbb w ffffffff cccccccccccccccc w xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
+               // |26 bit|   |-117--| |-----142------|
+               // b = format bit len, o = odd parity of last 3 bits
+               // f = facility code, c = card number
+               // w = wiegand parity
+               // (26 bit format shown)
+
+               uint32_t fc = 0;
+               uint32_t cardnum = 0;
+               uint32_t code1 = 0;
+               uint32_t code2 = 0;
+               uint8_t fmtLen = bytebits_to_byte(dest,8);
+               if (fmtLen==26){
+                       fc = bytebits_to_byte(dest+9, 8);
+                       cardnum = bytebits_to_byte(dest+17, 16);
+                       code1 = bytebits_to_byte(dest+8,fmtLen);
+                       Dbprintf("AWID Found - BitLength: %d, FC: %d, Card: %d - Wiegand: %x, Raw: %08x%08x%08x", fmtLen, fc, cardnum, code1, rawHi2, rawHi, rawLo);
+               } else {
+                       cardnum = bytebits_to_byte(dest+8+(fmtLen-17), 16);
+                       if (fmtLen>32){
+                               code1 = bytebits_to_byte(dest+8,fmtLen-32);
+                               code2 = bytebits_to_byte(dest+8+(fmtLen-32),32);
+                               Dbprintf("AWID Found - BitLength: %d -unknown BitLength- (%d) - Wiegand: %x%08x, Raw: %08x%08x%08x", fmtLen, cardnum, code1, code2, rawHi2, rawHi, rawLo);
+                       } else{
+                               code1 = bytebits_to_byte(dest+8,fmtLen);
+                               Dbprintf("AWID Found - BitLength: %d -unknown BitLength- (%d) - Wiegand: %x, Raw: %08x%08x%08x", fmtLen, cardnum, code1, rawHi2, rawHi, rawLo);
                        }
                }
+               if (findone){
+                       if (ledcontrol) LED_A_OFF();
+                       break;
+               }
+               // reset
+               idx = 0;
                WDT_HIT();
        }
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+       DbpString("Stopped");
+       if (ledcontrol) LED_A_OFF();
+}
+
+void CmdEM410xdemod(int findone, int *high, int *low, int ledcontrol)
+{
+       uint8_t *dest = BigBuf_get_addr();
+
+       size_t size=0, idx=0;
+       int clk=0, invert=0, errCnt=0, maxErr=20;
+       uint32_t hi=0;
+       uint64_t lo=0;
+       //clear read buffer
+       BigBuf_Clear_keep_EM();
+       // Configure to go in 125Khz listen mode
+       LFSetupFPGAForADC(95, true);
+
+       while(!BUTTON_PRESS() && !usb_poll_validate_length()) {
+
+               WDT_HIT();
+               if (ledcontrol) LED_A_ON();
+
+               DoAcquisition_default(-1,true);
+               size  = BigBuf_max_traceLen();
+               //askdemod and manchester decode
+               if (size > 16385) size = 16385; //big enough to catch 2 sequences of largest format
+               errCnt = askdemod(dest, &size, &clk, &invert, maxErr, 0, 1);
+               WDT_HIT();
+
+               if (errCnt<0) continue;
+       
+               errCnt = Em410xDecode(dest, &size, &idx, &hi, &lo);
+               if (errCnt){
+                       if (size>64){
+                               Dbprintf("EM XL TAG ID: %06x%08x%08x - (%05d_%03d_%08d)",
+                                 hi,
+                                 (uint32_t)(lo>>32),
+                                 (uint32_t)lo,
+                                 (uint32_t)(lo&0xFFFF),
+                                 (uint32_t)((lo>>16LL) & 0xFF),
+                                 (uint32_t)(lo & 0xFFFFFF));
+                       } else {
+                               Dbprintf("EM TAG ID: %02x%08x - (%05d_%03d_%08d)",
+                                 (uint32_t)(lo>>32),
+                                 (uint32_t)lo,
+                                 (uint32_t)(lo&0xFFFF),
+                                 (uint32_t)((lo>>16LL) & 0xFF),
+                                 (uint32_t)(lo & 0xFFFFFF));
+                       }
+
+                       if (findone){
+                               if (ledcontrol) LED_A_OFF();
+                               *high=lo>>32;
+                               *low=lo & 0xFFFFFFFF;
+                               break;
+                       }
+               }
+               WDT_HIT();
+               hi = lo = size = idx = 0;
+               clk = invert = errCnt = 0;
+       }
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+       DbpString("Stopped");
+       if (ledcontrol) LED_A_OFF();
+}
+
+void CmdIOdemodFSK(int findone, int *high, int *low, int ledcontrol)
+{
+       uint8_t *dest = BigBuf_get_addr();
+       int idx=0;
+       uint32_t code=0, code2=0;
+       uint8_t version=0;
+       uint8_t facilitycode=0;
+       uint16_t number=0;
+       int dummyIdx=0;
+       //clear read buffer
+       BigBuf_Clear_keep_EM();
+       // Configure to go in 125Khz listen mode
+       LFSetupFPGAForADC(95, true);
+
+       while(!BUTTON_PRESS() && !usb_poll_validate_length()) {
+               WDT_HIT();
+               if (ledcontrol) LED_A_ON();
+               DoAcquisition_default(-1,true);
+               //fskdemod and get start index
+               WDT_HIT();
+               idx = IOdemodFSK(dest, BigBuf_max_traceLen(), &dummyIdx);
+               if (idx<0) continue;
+               //valid tag found
+
+               //Index map
+               //0           10          20          30          40          50          60
+               //|           |           |           |           |           |           |
+               //01234567 8 90123456 7 89012345 6 78901234 5 67890123 4 56789012 3 45678901 23
+               //-----------------------------------------------------------------------------
+               //00000000 0 11110000 1 facility 1 version* 1 code*one 1 code*two 1 ???????? 11
+               //
+               //XSF(version)facility:codeone+codetwo
+               //Handle the data
+               if(findone){ //only print binary if we are doing one
+                       Dbprintf("%d%d%d%d%d%d%d%d %d",dest[idx],   dest[idx+1],   dest[idx+2],dest[idx+3],dest[idx+4],dest[idx+5],dest[idx+6],dest[idx+7],dest[idx+8]);
+                       Dbprintf("%d%d%d%d%d%d%d%d %d",dest[idx+9], dest[idx+10],dest[idx+11],dest[idx+12],dest[idx+13],dest[idx+14],dest[idx+15],dest[idx+16],dest[idx+17]);
+                       Dbprintf("%d%d%d%d%d%d%d%d %d",dest[idx+18],dest[idx+19],dest[idx+20],dest[idx+21],dest[idx+22],dest[idx+23],dest[idx+24],dest[idx+25],dest[idx+26]);
+                       Dbprintf("%d%d%d%d%d%d%d%d %d",dest[idx+27],dest[idx+28],dest[idx+29],dest[idx+30],dest[idx+31],dest[idx+32],dest[idx+33],dest[idx+34],dest[idx+35]);
+                       Dbprintf("%d%d%d%d%d%d%d%d %d",dest[idx+36],dest[idx+37],dest[idx+38],dest[idx+39],dest[idx+40],dest[idx+41],dest[idx+42],dest[idx+43],dest[idx+44]);
+                       Dbprintf("%d%d%d%d%d%d%d%d %d",dest[idx+45],dest[idx+46],dest[idx+47],dest[idx+48],dest[idx+49],dest[idx+50],dest[idx+51],dest[idx+52],dest[idx+53]);
+                       Dbprintf("%d%d%d%d%d%d%d%d %d%d",dest[idx+54],dest[idx+55],dest[idx+56],dest[idx+57],dest[idx+58],dest[idx+59],dest[idx+60],dest[idx+61],dest[idx+62],dest[idx+63]);
+               }
+               code = bytebits_to_byte(dest+idx,32);
+               code2 = bytebits_to_byte(dest+idx+32,32);
+               version = bytebits_to_byte(dest+idx+27,8); //14,4
+               facilitycode = bytebits_to_byte(dest+idx+18,8);
+               number = (bytebits_to_byte(dest+idx+36,8)<<8)|(bytebits_to_byte(dest+idx+45,8)); //36,9
+
+               Dbprintf("XSF(%02d)%02x:%05d (%08x%08x)",version,facilitycode,number,code,code2);
+               // if we're only looking for one tag
+               if (findone){
+                       if (ledcontrol) LED_A_OFF();
+                       //LED_A_OFF();
+                       *high=code;
+                       *low=code2;
+                       break;
+               }
+               code=code2=0;
+               version=facilitycode=0;
+               number=0;
+               idx=0;
+
+               WDT_HIT();
+       }
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+       DbpString("Stopped");
+       if (ledcontrol) LED_A_OFF();
+}
+
+/*------------------------------
+ * T5555/T5557/T5567/T5577 routines
+ *------------------------------
+ * NOTE: T55x7/T5555 configuration register definitions moved to protocols.h
+ *
+ * Relevant communication times in microsecond
+ * To compensate antenna falling times shorten the write times
+ * and enlarge the gap ones.
+ * Q5 tags seems to have issues when these values changes. 
+ */
+
+ /*
+ // Original Timings for reference
+//note startgap must be sent after tag has been powered up for more than 3ms (per T5557 ds)
+#define START_GAP 31*8 // was 250 // SPEC:  1*8 to 50*8 - typ 15*8 (or 15fc)
+#define WRITE_GAP 20*8 // was 160 // SPEC:  1*8 to 20*8 - typ 10*8 (or 10fc)
+#define WRITE_0   18*8 // was 144 // SPEC: 16*8 to 32*8 - typ 24*8 (or 24fc)
+#define WRITE_1   50*8 // was 400 // SPEC: 48*8 to 64*8 - typ 56*8 (or 56fc)  432 for T55x7; 448 for E5550
+#define READ_GAP  15*8 
+
+*/
+/* Q5 timing datasheet:
+ * Type                  |  MIN   | Typical |  Max   |
+ * Start_Gap             |  10*8  |    ?    |  50*8  |
+ * Write_Gap Normal mode |   8*8  |   14*8  |  20*8  | 
+ * Write_Gap Fast Mode   |   8*8  |    ?    |  20*8  |
+ * Write_0   Normal mode |  16*8  |   24*8  |  32*8  |
+ * Write_1   Normal mode |  48*8  |   56*8  |  64*8  |
+ * Write_0   Fast Mode   |   8*8  |   12*8  |  16*8  |
+ * Write_1   Fast Mode   |  24*8  |   28*8  |  32*8  |
+*/
+
+/* T5557 timing datasheet:
+ * Type                  |  MIN   | Typical |  Max   |
+ * Start_Gap             |  10*8  |    ?    |  50*8  |
+ * Write_Gap Normal mode |   8*8  |50-150us |  30*8  | 
+ * Write_Gap Fast Mode   |   8*8  |    ?    |  20*8  |
+ * Write_0   Normal mode |  16*8  |   24*8  |  31*8  | 
+ * Write_1   Normal mode |  48*8  |   54*8  |  63*8  | 
+ * Write_0   Fast Mode   |   8*8  |   12*8  |  15*8  |
+ * Write_1   Fast Mode   |  24*8  |   28*8  |  31*8  |
+*/
+
+/* T5577C timing datasheet for Fixed-Bit-Length protocol (defualt):
+ * Type                  |  MIN   | Typical |  Max   |
+ * Start_Gap             |   8*8  |   15*8  |  50*8  |
+ * Write_Gap Normal mode |   8*8  |   10*8  |  20*8  | 
+ * Write_Gap Fast Mode   |   8*8  |   10*8  |  20*8  |
+ * Write_0   Normal mode |  16*8  |   24*8  |  32*8  | 
+ * Write_1   Normal mode |  48*8  |   56*8  |  64*8  | 
+ * Write_0   Fast Mode   |   8*8  |   12*8  |  16*8  |
+ * Write_1   Fast Mode   |  24*8  |   28*8  |  32*8  |
+*/
+
+// Structure to hold Timing values.  In future will be simplier to add user changable timings.
+typedef struct  {
+       uint16_t  START_GAP;
+       uint16_t  WRITE_GAP;
+       uint16_t  WRITE_0;
+       uint16_t  WRITE_1;
+       uint16_t  WRITE_2;
+       uint16_t  WRITE_3;
+       uint16_t  READ_GAP;
+} T55xx_Timing;
+
+// Set Initial/Default Values.  Note: *8 can occure when used.  This should keep things simplier here.
+T55xx_Timing T55xx_Timing_FixedBit = { 31 * 8   , 20 * 8   , 18 * 8 , 50 * 8 , 0      , 0      , 15 * 8   };
+T55xx_Timing T55xx_Timing_LLR      = { 31 * 8   , 20 * 8   , 18 * 8 , 50 * 8 , 0      , 0      , 15 * 8   };
+T55xx_Timing T55xx_Timing_Leading0 = { 31 * 8   , 20 * 8   , 18 * 8 , 40 * 8 , 0      , 0      , 15 * 8   };
+T55xx_Timing T55xx_Timing_1of4     = { 31 * 8   , 20 * 8   , 18 * 8 , 34 * 8 , 50 * 8 , 66 * 8 , 15 * 8   };
+
+// Some defines for readability
+#define T55xx_DLMode_Fixed         0 // Default Mode
+#define T55xx_DLMode_LLR           1 // Long Leading Reference
+#define T55xx_DLMode_Leading0      2 // Leading Zero
+#define T55xx_DLMode_1of4          3 // 1 of 4
+#define T55xx_LongLeadingReference 4 // Value to tell Write Bit to send long reference
+// Macro for code readability
+#define BitStream_Byte(X) ((X) >> 3)
+#define BitStream_Bit(X)  ((X) &  7)  
+
+
+void TurnReadLFOn(int delay) {
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
+       // Give it a bit of time for the resonant antenna to settle.
+       WaitUS(delay); //155*8 //50*8
+}
+
+// Write one bit to card
+void T55xxWriteBit(int bit, T55xx_Timing *Timings) {
+
+       // If bit = 4 Send Long Leading Reference which is 138 + WRITE_0        
+       // Dbprintf ("Bits : %d",bit);
+       switch (bit){
+               case 0 : TurnReadLFOn(Timings->WRITE_0);             break; // Send bit  0/00
+               case 1 : TurnReadLFOn(Timings->WRITE_1);             break; // Send bit  1/01
+               case 2 : TurnReadLFOn(Timings->WRITE_2);             break; // Send bits   10
+               case 3 : TurnReadLFOn(Timings->WRITE_3);             break; // Send bits   11
+               case 4 : TurnReadLFOn(Timings->WRITE_0 + (136 * 8)); break; // Send Long Leading Reference
+       }
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+       WaitUS(Timings->WRITE_GAP);
+}
+
+// Function to abstract an Arbitrary length byte array to store bit pattern.
+// bit_array    - Array to hold data/bit pattern
+// start_offset - bit location to start storing new bits.
+// data         - upto 32 bits of data to store
+// num_bits     - how many bits (low x bits of data)  Max 32 bits at a time
+// max_len         - how many bytes can the bit_array hold (ensure no buffer overflow)
+// returns "Next" bit offset / bits stored (for next store)
+//int T55xx_SetBits (uint8_t *bit_array, int start_offset, uint32_t data      , int num_bits, int max_len)
+int T55xx_SetBits (uint8_t *BitStream, uint8_t start_offset, uint32_t data , uint8_t num_bits, uint8_t max_len)
+{
+       int8_t offset;
+       int8_t NextOffset = start_offset;
+
+       // Check if data will fit.
+       if ((start_offset + num_bits) <= (max_len*8)) {
+               // Loop through the data and store
+               for (offset = (num_bits-1); offset >= 0; offset--) {
+
+                       if ((data >> offset) & 1)  BitStream[BitStream_Byte(NextOffset)] |= (1         << BitStream_Bit(NextOffset));     // Set the bit to 1
+                       else                       BitStream[BitStream_Byte(NextOffset)] &= (0xff ^ (1 << BitStream_Bit(NextOffset)));    // Set the bit to 0
+
+                       NextOffset++;
+               }
+       }
+       else {
+               // Note: This should never happen unless some code changes cause it.  
+               // So short message for coders when testing.
+               Dbprintf ("T55 too many bits"); 
+       }
+       return NextOffset;
+}
+
+// Send one downlink command to the card 
+void T55xx_SendCMD (uint32_t Data, uint32_t Block, uint32_t Pwd, uint8_t arg) { 
+
+       /*
+               arg bits
+               xxxxxxx1 0x01 PwdMode
+               xxxxxx1x 0x02 Page
+               xxxxx1xx 0x04 testMode
+               xxx11xxx 0x18 downlink mode
+               xx1xxxxx 0x20 !reg_readmode
+               x1xxxxxx 0x40 called for a read, so no data packet
+               1xxxxxxx 0x80 reset
+
+       */
+       bool PwdMode      = ((arg & 0x01) == 0x01);
+       bool Page         =  (arg & 0x02);
+       bool testMode     = ((arg & 0x04) == 0x04);
+       uint8_t downlink_mode = (arg >> 3) & 0x03;
+       bool reg_readmode = ((arg & 0x20) == 0x20);
+       bool read_cmd     = ((arg & 0x40) == 0x40);
+       bool reset        =  (arg & 0x80);
+
+       uint8_t i = 0;
+       uint8_t BitStream[10];  // Max Downlink Command size ~74 bits, so 10 bytes (80 bits)
+       uint8_t BitStreamLen;
+       T55xx_Timing *Timing;
+       uint8_t SendBits;
+
+       // Assigning Downlink Timeing for write
+       switch (downlink_mode)
+       {
+               case T55xx_DLMode_Fixed    : Timing = &T55xx_Timing_FixedBit;  break; 
+               case T55xx_DLMode_LLR      : Timing = &T55xx_Timing_LLR;       break;
+               case T55xx_DLMode_Leading0 : Timing = &T55xx_Timing_Leading0;  break;
+               case T55xx_DLMode_1of4     : Timing = &T55xx_Timing_1of4;      break;
+               default:
+                               Timing = &T55xx_Timing_FixedBit;
+       }
+
+       // Build Bit Stream to send.
+       memset (BitStream,0x00,sizeof(BitStream));
+       
+       BitStreamLen = 0; // Ensure 0 bit index to start.
+       
+       // Add Leading 0 and 1 of 4 reference bit
+       if ((downlink_mode == T55xx_DLMode_Leading0) || (downlink_mode == T55xx_DLMode_1of4))
+               BitStreamLen = T55xx_SetBits (BitStream, BitStreamLen, 0, 1,sizeof(BitStream)); 
+
+       // Add extra reference 0 for 1 of 4
+       if (downlink_mode == T55xx_DLMode_1of4)
+               BitStreamLen = T55xx_SetBits (BitStream, BitStreamLen, 0, 1,sizeof(BitStream)); 
+
+       // Add Opcode 
+       if (reset) {
+               //  Reset : r*) 00
+               BitStreamLen = T55xx_SetBits (BitStream, BitStreamLen, 0, 2,sizeof(BitStream)); 
+       }
+       else
+       {
+               if (testMode) Dbprintf("TestMODE");
+               BitStreamLen = T55xx_SetBits (BitStream, BitStreamLen,testMode ? 0 : 1    , 1,sizeof(BitStream));
+               BitStreamLen = T55xx_SetBits (BitStream, BitStreamLen,testMode ? 1 : Page , 1,sizeof(BitStream));
+
+               if (PwdMode) {
+                       // Leading 0 and 1 of 4 00 fixed bits if passsword used         
+                       if ((downlink_mode == T55xx_DLMode_Leading0) || (downlink_mode == T55xx_DLMode_1of4)) {
+                               BitStreamLen = T55xx_SetBits (BitStream, BitStreamLen, 0, 2,sizeof(BitStream));
+                       }
+                       BitStreamLen = T55xx_SetBits (BitStream, BitStreamLen, Pwd, 32,sizeof(BitStream));
+               }
+
+               // Add Lock bit 0
+               if (!reg_readmode) BitStreamLen = T55xx_SetBits (BitStream, BitStreamLen, 0, 1,sizeof(BitStream));
+
+               // Add Data if a write command
+               if (!read_cmd)  BitStreamLen = T55xx_SetBits (BitStream, BitStreamLen, Data, 32,sizeof(BitStream));
+
+               // Add Address
+               if (!reg_readmode) BitStreamLen = T55xx_SetBits (BitStream, BitStreamLen, Block, 3,sizeof(BitStream));
+       }
+
+       // Send Bits to T55xx
+       // Set up FPGA, 125kHz
+       LFSetupFPGAForADC(95, true);
+       StartTicks();
+       // make sure tag is fully powered up...
+       WaitMS(5);
+       // Trigger T55x7 in mode.
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+       WaitUS(Timing->START_GAP);
+
+       // If long leading 0 send long reference pulse
+       if (downlink_mode ==  T55xx_DLMode_LLR) 
+               T55xxWriteBit (T55xx_LongLeadingReference,Timing); // Send Long Leading Start Reference
+
+       if ((downlink_mode ==  T55xx_DLMode_1of4) && (BitStreamLen > 0)) { // 1 of 4 need to send 2 bits at a time
+               for ( i = 0; i < BitStreamLen-1; i+=2 ) {
+                       SendBits  = (BitStream[BitStream_Byte(i  )] >> (BitStream_Bit(i  )) & 1) << 1;   // Bit i
+                       SendBits += (BitStream[BitStream_Byte(i+1)] >> (BitStream_Bit(i+1)) & 1);        // Bit i+1;
+                       T55xxWriteBit (SendBits & 3,Timing);
+               }
+       }
+       else {
+               for (i = 0; i < BitStreamLen; i++) {
+                       SendBits = (BitStream[BitStream_Byte(i)] >> BitStream_Bit(i));
+                       T55xxWriteBit (SendBits & 1,Timing);
+               }
+       }
+}
+
+// Send T5577 reset command then read stream (see if we can identify the start of the stream)
+void T55xxResetRead(void) {
+       LED_A_ON();
+
+       //  send  r* 00 
+       uint8_t arg = 0x80;  // SendCMD will add correct reference mode based on flags (when added).
+
+       // Add in downlink_mode when ready
+       //    arg |= 0x00;  // dlmode << 3  (00 default - 08 leading 0 - 10 Fixed - 18 1 of 4 )
+
+       //clear buffer now so it does not interfere with timing later
+       BigBuf_Clear_keep_EM();
+
+       T55xx_SendCMD (0, 0, 0, arg); //, true);
+
+       TurnReadLFOn(T55xx_Timing_FixedBit.READ_GAP);
+
+       // Acquisition
+       DoPartialAcquisition(0, true, BigBuf_max_traceLen(), 0);
+
+       // Turn the field off
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); // field off
+       cmd_send(CMD_ACK,0,0,0,0,0);    
+       LED_A_OFF();
+}
+
+// Write one card block in page 0, no lock
+void T55xxWriteBlock(uint32_t Data, uint32_t Block, uint32_t Pwd, uint8_t arg) {
+       /*
+               arg bits
+               xxxxxxx1 0x01 PwdMode
+               xxxxxx1x 0x02 Page
+               xxxxx1xx 0x04 testMode
+               xxx11xxx 0x18 downlink mode
+               xx1xxxxx 0x20 !reg_readmode
+               x1xxxxxx 0x40 called for a read, so no data packet
+               1xxxxxxx 0x80 reset
+       */
+       
+       bool testMode = ((arg & 0x04) == 0x04);
+       arg &= (0xff ^ 0x40); // Called for a write, so ensure it is clear/0
+       
+       LED_A_ON ();
+       T55xx_SendCMD (Data, Block, Pwd, arg) ;//, false); 
+
+       // Perform write (nominal is 5.6 ms for T55x7 and 18ms for E5550,
+       // so wait a little more)
+
+       // "there is a clock delay before programming" 
+       //  - programming takes ~5.6ms for t5577 ~18ms for E5550 or t5567
+       //  so we should wait 1 clock + 5.6ms then read response? 
+       //  but we need to know we are dealing with t5577 vs t5567 vs e5550 (or q5) marshmellow...
+       if (testMode) {
+               //TESTMODE TIMING TESTS: 
+               // <566us does nothing 
+               // 566-568 switches between wiping to 0s and doing nothing
+               // 5184 wipes and allows 1 block to be programmed.
+               // indefinite power on wipes and then programs all blocks with bitshifted data sent.
+               TurnReadLFOn(5184); 
+
+       } else {
+               TurnReadLFOn(20 * 1000);
+               //could attempt to do a read to confirm write took
+               // as the tag should repeat back the new block 
+               // until it is reset, but to confirm it we would 
+               // need to know the current block 0 config mode for
+               // modulation clock an other details to demod the response...
+               // response should be (for t55x7) a 0 bit then (ST if on) 
+               // block data written in on repeat until reset. 
+
+               //DoPartialAcquisition(20, true, 12000);
+       }
+       // turn field off
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
+
+       cmd_send(CMD_ACK,0,0,0,0,0);
+
+       LED_A_OFF ();
+}
+
+// Read one card block in page [page]
+void T55xxReadBlock (uint16_t arg0, uint8_t Block, uint32_t Pwd) {//, struct T55xx_Timing *Timing) {
+
+       LED_A_ON();
+
+       /*
+               arg bits
+               xxxxxxx1 0x01 PwdMode
+               xxxxxx1x 0x02 Page
+               xxxxx1xx 0x04 testMode
+               xxx11xxx 0x18 downlink mode
+               xx1xxxxx 0x20 !reg_readmode
+               x1xxxxxx 0x40 called for a read, so no data packet
+               1xxxxxxx 0x80 reset
+       */
+
+       // Set Read Flag to ensure SendCMD does not add "data" to the packet
+       arg0 |= 0x40;
+
+       // RegRead Mode true of block 0xff
+       if (Block == 0xff) arg0 |= 0x20;
+       
+       //make sure block is at max 7
+       Block &= 0x7;
+
+       //clear buffer now so it does not interfere with timing later
+       BigBuf_Clear_ext(false);
+
+       T55xx_SendCMD (0, Block, Pwd, arg0); //, true);
+
+       // Turn field on to read the response
+       // 137*8 seems to get to the start of data pretty well... 
+       //  but we want to go past the start and let the repeating data settle in...
+       TurnReadLFOn(210*8); 
+
+       // Acquisition
+       // Now do the acquisition
+       DoPartialAcquisition(0, true, 12000, 0);
+
+       // Turn the field off
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); // field off
+       cmd_send(CMD_ACK,0,0,0,0,0);    
+
+       LED_A_OFF();
+}
+
+void T55xxWakeUp(uint32_t Pwd){
+       LED_B_ON();
+       /*
+               arg bits
+               xxxxxxx1 0x01 PwdMode
+               xxxxxx1x 0x02 Page
+               xxxxx1xx 0x04 testMode
+               xxx11xxx 0x18 downlink mode
+               xx1xxxxx 0x20 !reg_readmode 
+               x1xxxxxx 0x40 called for a read, so no data packet
+               1xxxxxxx 0x80 reset
+       */
+
+       // r* 10 (00) <pwd>   r* for llr , L0 and 1/4 - (00) for L0 and 1/4 - All handled in SendCMD
+       // So, default Opcode 10 and pwd.
+       uint8_t arg = 0x01 | 0x40 | 0x20; //Password Read Call no data | reg_read no block
+
+       // Add in downlink_mode when ready
+       //    arg |= 0x00;  // dlmode << 3  (00 default - 08 leading 0 - 10 Fixed - 18 1 of 4 )
+
+       T55xx_SendCMD (0, 0, Pwd, arg); //, true);
+
+       // Turn and leave field on to let the begin repeating transmission
+       TurnReadLFOn(20*1000);
+}
+
+/*-------------- Cloning routines -----------*/
+
+void WriteT55xx(uint32_t *blockdata, uint8_t startblock, uint8_t numblocks) {
+       // write last block first and config block last (if included)
+       for (uint8_t i = numblocks+startblock; i > startblock; i--) {
+               T55xxWriteBlock(blockdata[i-1],i-1,0,0);//,false); //,&T55xx_Timing_FixedBit);
+               //T55xx_SendCMD (blockdata[i-1],i-1,0,0);//,false); //,&T55xx_Timing_FixedBit);
+       }
+}
+
+// Copy a HID-like card (e.g. HID Proximity, Paradox) to a T55x7 compatible card
+void CopyHIDtoT55x7(uint32_t hi2, uint32_t hi, uint32_t lo, uint8_t longFMT, uint8_t preamble) {
+       uint32_t data[] = {0,0,0,0,0,0,0};
+       uint8_t last_block = 0;
+
+       if (longFMT) {
+               // Ensure no more than 84 bits supplied
+               if (hi2>0xFFFFF) {
+                       DbpString("Tags can only have 84 bits.");
+                       return;
+               }
+               // Build the 6 data blocks for supplied 84bit ID
+               last_block = 6;
+               // load preamble & long format identifier (9E manchester encoded)
+               data[1] = (preamble << 24) | 0x96A900 | (manchesterEncode2Bytes((hi2 >> 16) & 0xF) & 0xFF);
+               // load raw id from hi2, hi, lo to data blocks (manchester encoded)
+               data[2] = manchesterEncode2Bytes(hi2 & 0xFFFF);
+               data[3] = manchesterEncode2Bytes(hi >> 16);
+               data[4] = manchesterEncode2Bytes(hi & 0xFFFF);
+               data[5] = manchesterEncode2Bytes(lo >> 16);
+               data[6] = manchesterEncode2Bytes(lo & 0xFFFF);
+       } else {
+               // Ensure no more than 44 bits supplied
+               if (hi>0xFFF) {
+                       DbpString("Tags can only have 44 bits.");
+                       return;
+               }
+               // Build the 3 data blocks for supplied 44bit ID
+               last_block = 3;
+               // load preamble
+               data[1] = (preamble << 24) | (manchesterEncode2Bytes(hi) & 0xFFFFFF);
+               data[2] = manchesterEncode2Bytes(lo >> 16);
+               data[3] = manchesterEncode2Bytes(lo & 0xFFFF);
+       }
+       // load chip config block
+       data[0] = T55x7_BITRATE_RF_50 | T55x7_MODULATION_FSK2a | last_block << T55x7_MAXBLOCK_SHIFT;
+
+       //TODO add selection of chip for Q5 or T55x7
+       // data[0] = (((50-2)/2)<<T5555_BITRATE_SHIFT) | T5555_MODULATION_FSK2 | T5555_INVERT_OUTPUT | last_block << T5555_MAXBLOCK_SHIFT;
+
+       LED_D_ON();
+       // Program the data blocks for supplied ID
+       // and the block 0 for HID format
+       WriteT55xx(data, 0, last_block+1);
+
+       LED_D_OFF();
+
+       DbpString("DONE!");
+}
+
+void CopyIOtoT55x7(uint32_t hi, uint32_t lo) {
+       uint32_t data[] = {T55x7_BITRATE_RF_64 | T55x7_MODULATION_FSK2a | (2 << T55x7_MAXBLOCK_SHIFT), hi, lo};
+       //TODO add selection of chip for Q5 or T55x7
+       // data[0] = (((64-2)/2)<<T5555_BITRATE_SHIFT) | T5555_MODULATION_FSK2 | T5555_INVERT_OUTPUT | 2 << T5555_MAXBLOCK_SHIFT;
+
+       LED_D_ON();
+       // Program the data blocks for supplied ID
+       // and the block 0 config
+       WriteT55xx(data, 0, 3);
+
+       LED_D_OFF();
+
+       DbpString("DONE!");
+}
+
+// Clone Indala 64-bit tag by UID to T55x7
+void CopyIndala64toT55x7(uint32_t hi, uint32_t lo) {
+       //Program the 2 data blocks for supplied 64bit UID
+       // and the Config for Indala 64 format (RF/32;PSK1 with RF/2;Maxblock=2)
+       uint32_t data[] = { T55x7_BITRATE_RF_32 | T55x7_MODULATION_PSK1 | (2 << T55x7_MAXBLOCK_SHIFT), hi, lo};
+       //TODO add selection of chip for Q5 or T55x7
+       // data[0] = (((32-2)/2)<<T5555_BITRATE_SHIFT) | T5555_MODULATION_PSK1 | 2 << T5555_MAXBLOCK_SHIFT;
+
+       WriteT55xx(data, 0, 3);
+       //Alternative config for Indala (Extended mode;RF/32;PSK1 with RF/2;Maxblock=2;Inverse data)
+       //      T5567WriteBlock(0x603E1042,0);
+       DbpString("DONE!");
+}
+// Clone Indala 224-bit tag by UID to T55x7
+void CopyIndala224toT55x7(uint32_t uid1, uint32_t uid2, uint32_t uid3, uint32_t uid4, uint32_t uid5, uint32_t uid6, uint32_t uid7) {
+       //Program the 7 data blocks for supplied 224bit UID
+       uint32_t data[] = {0, uid1, uid2, uid3, uid4, uid5, uid6, uid7};
+       // and the block 0 for Indala224 format 
+       //Config for Indala (RF/32;PSK2 with RF/2;Maxblock=7)
+       data[0] = T55x7_BITRATE_RF_32 | T55x7_MODULATION_PSK2 | (7 << T55x7_MAXBLOCK_SHIFT);
+       //TODO add selection of chip for Q5 or T55x7
+       // data[0] = (((32-2)>>1)<<T5555_BITRATE_SHIFT) | T5555_MODULATION_PSK2 | 7 << T5555_MAXBLOCK_SHIFT;
+       WriteT55xx(data, 0, 8);
+       //Alternative config for Indala (Extended mode;RF/32;PSK1 with RF/2;Maxblock=7;Inverse data)
+       //      T5567WriteBlock(0x603E10E2,0);
+       DbpString("DONE!");
+}
+// clone viking tag to T55xx
+void CopyVikingtoT55xx(uint32_t block1, uint32_t block2, uint8_t Q5) {
+       uint32_t data[] = {T55x7_BITRATE_RF_32 | T55x7_MODULATION_MANCHESTER | (2 << T55x7_MAXBLOCK_SHIFT), block1, block2};
+       if (Q5) data[0] = T5555_SET_BITRATE(32) | T5555_MODULATION_MANCHESTER | 2 << T5555_MAXBLOCK_SHIFT;
+       // Program the data blocks for supplied ID and the block 0 config
+       WriteT55xx(data, 0, 3);
+       LED_D_OFF();
+       cmd_send(CMD_ACK,0,0,0,0,0);
+}
+
+// Define 9bit header for EM410x tags
+#define EM410X_HEADER            0x1FF
+#define EM410X_ID_LENGTH       40
+
+void WriteEM410x(uint32_t card, uint32_t id_hi, uint32_t id_lo) {
+       int i, id_bit;
+       uint64_t id = EM410X_HEADER;
+       uint64_t rev_id = 0;    // reversed ID
+       int c_parity[4];        // column parity
+       int r_parity = 0;       // row parity
+       uint32_t clock = 0;
+
+       // Reverse ID bits given as parameter (for simpler operations)
+       for (i = 0; i < EM410X_ID_LENGTH; ++i) {
+               if (i < 32) {
+                       rev_id = (rev_id << 1) | (id_lo & 1);
+                       id_lo >>= 1;
+               } else {
+                       rev_id = (rev_id << 1) | (id_hi & 1);
+                       id_hi >>= 1;
+               }
+       }
+
+       for (i = 0; i < EM410X_ID_LENGTH; ++i) {
+               id_bit = rev_id & 1;
+
+               if (i % 4 == 0) {
+                       // Don't write row parity bit at start of parsing
+                       if (i)
+                               id = (id << 1) | r_parity;
+                       // Start counting parity for new row
+                       r_parity = id_bit;
+               } else {
+                       // Count row parity
+                       r_parity ^= id_bit;
+               }
+
+               // First elements in column?
+               if (i < 4)
+                       // Fill out first elements
+                       c_parity[i] = id_bit;
+               else
+                       // Count column parity
+                       c_parity[i % 4] ^= id_bit;
+
+               // Insert ID bit
+               id = (id << 1) | id_bit;
+               rev_id >>= 1;
+       }
+
+       // Insert parity bit of last row
+       id = (id << 1) | r_parity;
+
+       // Fill out column parity at the end of tag
+       for (i = 0; i < 4; ++i)
+               id = (id << 1) | c_parity[i];
+
+       // Add stop bit
+       id <<= 1;
+
+       Dbprintf("Started writing %s tag ...", card ? "T55x7":"T5555");
+       LED_D_ON();
+
+       // Write EM410x ID
+       uint32_t data[] = {0, (uint32_t)(id>>32), (uint32_t)(id & 0xFFFFFFFF)};
+
+       clock = (card & 0xFF00) >> 8;
+       clock = (clock == 0) ? 64 : clock;
+       Dbprintf("Clock rate: %d", clock);
+       if (card & 0xFF) { //t55x7
+               clock = GetT55xxClockBit(clock);                        
+               if (clock == 0) {
+                       Dbprintf("Invalid clock rate: %d", clock);
+                       return;
+               }
+               data[0] = clock | T55x7_MODULATION_MANCHESTER | (2 << T55x7_MAXBLOCK_SHIFT);
+       } else { //t5555 (Q5)
+               data[0] = T5555_SET_BITRATE(clock) | T5555_MODULATION_MANCHESTER | (2 << T5555_MAXBLOCK_SHIFT);
+       }
+
+       WriteT55xx(data, 0, 3);
+
+       LED_D_OFF();
+       Dbprintf("Tag %s written with 0x%08x%08x\n", card ? "T55x7":"T5555",
+                        (uint32_t)(id >> 32), (uint32_t)id);
+}
+
+//-----------------------------------
+// EM4469 / EM4305 routines
+//-----------------------------------
+#define FWD_CMD_LOGIN 0xC //including the even parity, binary mirrored
+#define FWD_CMD_WRITE 0xA
+#define FWD_CMD_READ 0x9
+#define FWD_CMD_DISABLE 0x5
+#define FWD_CMD_PROTECT 0x3
+
+uint8_t forwardLink_data[64]; //array of forwarded bits
+uint8_t * forward_ptr; //ptr for forward message preparation
+uint8_t fwd_bit_sz; //forwardlink bit counter
+uint8_t * fwd_write_ptr; //forwardlink bit pointer
+
+//====================================================================
+// prepares command bits
+// see EM4469 spec
+//====================================================================
+//--------------------------------------------------------------------
+//  VALUES TAKEN FROM EM4x function: SendForward
+//  START_GAP = 440;       (55*8) cycles at 125Khz (8us = 1cycle)
+//  WRITE_GAP = 128;       (16*8)
+//  WRITE_1   = 256 32*8;  (32*8) 
+
+//  These timings work for 4469/4269/4305 (with the 55*8 above)
+//  WRITE_0 = 23*8 , 9*8  SpinDelayUs(23*8); 
+
+uint8_t Prepare_Cmd( uint8_t cmd ) {
+
+       *forward_ptr++ = 0; //start bit
+       *forward_ptr++ = 0; //second pause for 4050 code
+
+       *forward_ptr++ = cmd;
+       cmd >>= 1;
+       *forward_ptr++ = cmd;
+       cmd >>= 1;
+       *forward_ptr++ = cmd;
+       cmd >>= 1;
+       *forward_ptr++ = cmd;
+
+       return 6; //return number of emited bits
+}
+
+//====================================================================
+// prepares address bits
+// see EM4469 spec
+//====================================================================
+uint8_t Prepare_Addr( uint8_t addr ) {
+
+       register uint8_t line_parity;
+
+       uint8_t i;
+       line_parity = 0;
+       for(i=0;i<6;i++) {
+               *forward_ptr++ = addr;
+               line_parity ^= addr;
+               addr >>= 1;
+       }
+
+       *forward_ptr++ = (line_parity & 1);
+
+       return 7; //return number of emited bits
+}
+
+//====================================================================
+// prepares data bits intreleaved with parity bits
+// see EM4469 spec
+//====================================================================
+uint8_t Prepare_Data( uint16_t data_low, uint16_t data_hi) {
+
+       register uint8_t line_parity;
+       register uint8_t column_parity;
+       register uint8_t i, j;
+       register uint16_t data;
+
+       data = data_low;
+       column_parity = 0;
+
+       for(i=0; i<4; i++) {
+               line_parity = 0;
+               for(j=0; j<8; j++) {
+                       line_parity ^= data;
+                       column_parity ^= (data & 1) << j;
+                       *forward_ptr++ = data;
+                       data >>= 1;
+               }
+               *forward_ptr++ = line_parity;
+               if(i == 1)
+                       data = data_hi;
+       }
+
+       for(j=0; j<8; j++) {
+               *forward_ptr++ = column_parity;
+               column_parity >>= 1;
+       }
+       *forward_ptr = 0;
+
+       return 45; //return number of emited bits
+}
+
+//====================================================================
+// Forward Link send function
+// Requires: forwarLink_data filled with valid bits (1 bit per byte)
+// fwd_bit_count set with number of bits to be sent
+//====================================================================
+void SendForward(uint8_t fwd_bit_count) {
+
+       fwd_write_ptr = forwardLink_data;
+       fwd_bit_sz = fwd_bit_count;
+
+       // Set up FPGA, 125kHz or 95 divisor
+       LFSetupFPGAForADC(95, true);
+
+       // force 1st mod pulse (start gap must be longer for 4305)
+       fwd_bit_sz--; //prepare next bit modulation
+       fwd_write_ptr++;
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); // field off
+       WaitUS(55*8); //55 cycles off (8us each)for 4305  //another reader has 37 here...
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);//field on
+       WaitUS(18*8); //18 cycles on (8us each)
+
+       // now start writting - each bit should be 32*8 total length
+       while(fwd_bit_sz-- > 0) { //prepare next bit modulation
+               if(((*fwd_write_ptr++) & 1) == 1)
+                       WaitUS(32*8); //32 cycles at 125Khz (8us each)
+               else {
+                       //These timings work for 4469/4269/4305 (with the 55*8 above)
+                       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); // field off
+                       WaitUS(23*8); //23 cycles off (8us each)
+                       FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);//field on
+                       WaitUS((32-23)*8); //remaining cycles on (8us each)
+               }
+       }
+}
+
+void EM4xLogin(uint32_t Password) {
+
+       uint8_t fwd_bit_count;
+
+       forward_ptr = forwardLink_data;
+       fwd_bit_count = Prepare_Cmd( FWD_CMD_LOGIN );
+       fwd_bit_count += Prepare_Data( Password&0xFFFF, Password>>16 );
+
+       SendForward(fwd_bit_count);
+
+       //Wait for command to complete
+       SpinDelay(20);
+}
+
+void EM4xReadWord(uint8_t Address, uint32_t Pwd, uint8_t PwdMode) {
+
+       uint8_t fwd_bit_count;
+
+       // Clear destination buffer before sending the command
+       BigBuf_Clear_ext(false);
+
+       LED_A_ON();
+       StartTicks();
+       //If password mode do login
+       if (PwdMode == 1) EM4xLogin(Pwd);
+
+       forward_ptr = forwardLink_data;
+       fwd_bit_count = Prepare_Cmd( FWD_CMD_READ );
+       fwd_bit_count += Prepare_Addr( Address );
+
+       SendForward(fwd_bit_count);
+       WaitUS(400);
+       // Now do the acquisition
+       DoPartialAcquisition(20, true, 6000, 1000);
+       
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); // field off
+       LED_A_OFF();
+       cmd_send(CMD_ACK,0,0,0,0,0);
+}
+
+void EM4xWriteWord(uint32_t flag, uint32_t Data, uint32_t Pwd) {
+       
+       bool PwdMode = (flag & 0x1);
+       uint8_t Address = (flag >> 8) & 0xFF;
+       uint8_t fwd_bit_count;
+
+       //clear buffer now so it does not interfere with timing later
+       BigBuf_Clear_ext(false);
+
+       LED_A_ON();
+       StartTicks();
+       //If password mode do login
+       if (PwdMode) EM4xLogin(Pwd);
+
+       forward_ptr = forwardLink_data;
+       fwd_bit_count = Prepare_Cmd( FWD_CMD_WRITE );
+       fwd_bit_count += Prepare_Addr( Address );
+       fwd_bit_count += Prepare_Data( Data&0xFFFF, Data>>16 );
+
+       SendForward(fwd_bit_count);
+
+       //Wait for write to complete
+       //SpinDelay(10);
+
+       WaitUS(6500);
+       //Capture response if one exists
+       DoPartialAcquisition(20, true, 6000, 1000);
+
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); // field off
+       LED_A_OFF();
+       cmd_send(CMD_ACK,0,0,0,0,0);
+}
+
+void EM4xProtect(uint32_t flag, uint32_t Data, uint32_t Pwd) {
+       
+       bool PwdMode = (flag & 0x1);
+       uint8_t fwd_bit_count;
+
+       //clear buffer now so it does not interfere with timing later
+       BigBuf_Clear_ext(false);
+
+       LED_A_ON();
+       StartTicks();
+       //If password mode do login
+       if (PwdMode) EM4xLogin(Pwd);
+
+       forward_ptr = forwardLink_data;
+       fwd_bit_count = Prepare_Cmd( FWD_CMD_PROTECT );
+
+       //unsure if this needs the full packet config...
+       fwd_bit_count += Prepare_Data( Data&0xFFFF, Data>>16 );
+
+       SendForward(fwd_bit_count);
+
+       //Wait for write to complete
+       //SpinDelay(10);
+
+       WaitUS(6500);
+       //Capture response if one exists
+       DoPartialAcquisition(20, true, 6000, 1000);
+
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); // field off
+       LED_A_OFF();
+       cmd_send(CMD_ACK,0,0,0,0,0);
+}
+/*
+Reading a COTAG.
+
+COTAG needs the reader to send a startsequence and the card has an extreme slow datarate.
+because of this, we can "sample" the data signal but we interpreate it to Manchester direct.
+
+READER START SEQUENCE:
+burst 800 us,    gap   2.2 msecs
+burst 3.6 msecs  gap   2.2 msecs
+burst 800 us     gap   2.2 msecs
+pulse 3.6 msecs
+
+This triggers a COTAG tag to response
+*/
+void Cotag(uint32_t arg0) {
+
+#define OFF     { FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); WaitUS(2035); }
+#define ON(x)   { FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD); WaitUS((x)); }
+
+       uint8_t rawsignal = arg0 & 0xF;
+
+       LED_A_ON();
+
+       // Switching to LF image on FPGA. This might empty BigBuff
+       FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
+
+       //clear buffer now so it does not interfere with timing later
+       BigBuf_Clear_ext(false);
+
+       // Set up FPGA, 132kHz to power up the tag
+       FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 89);
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
+
+       // Connect the A/D to the peak-detected low-frequency path.
+       SetAdcMuxFor(GPIO_MUXSEL_LOPKD);
+
+       // Now set up the SSC to get the ADC samples that are now streaming at us.
+       FpgaSetupSsc(FPGA_MAJOR_MODE_LF_ADC);
+
+       // start clock - 1.5ticks is 1us
+       StartTicks();
+
+       //send COTAG start pulse
+       ON(740)  OFF
+       ON(3330) OFF
+       ON(740)  OFF
+       ON(1000)
+
+       switch(rawsignal) {
+               case 0: doCotagAcquisition(50000); break;
+               case 1: doCotagAcquisitionManchester(); break;
+               case 2: DoAcquisition_config(true, 0); break;
+       }
+
+       // Turn the field off
+       FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); // field off
+       cmd_send(CMD_ACK,0,0,0,0,0);
+       LED_A_OFF();
 }
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