lf demod cleanup nrz clock detect fixes

[proxmark3-svn] / common / lfdemod.c

diff --git a/common/lfdemod.c b/common/lfdemod.c
index 7d40d22e5aa44551835ae4ada1f69947f132e488..7297c4e69835f3ab491a3b9a58776adad91f2c5c 100644 (file)
--- a/common/lfdemod.c
+++ b/common/lfdemod.c
@@ -11,6 +11,20 @@
 #include <stdlib.h>
 #include <string.h>
 #include "lfdemod.h"
 #include <stdlib.h>
 #include <string.h>
 #include "lfdemod.h"

+#include "common.h"
+
+/* //un_comment to allow debug print calls when used not on device
+void dummy(char *fmt, ...){}
+
+#ifndef ON_DEVICE
+#include "ui.h"
+#define prnt PrintAndLog
+#else 
+
+#define prnt dummy
+#endif
+*/
+

 uint8_t justNoise(uint8_t *BitStream, size_t size)
 {
        static const uint8_t THRESHOLD = 123;
 uint8_t justNoise(uint8_t *BitStream, size_t size)
 {
        static const uint8_t THRESHOLD = 123;


@@ -282,6 +296,16 @@ int manrawdecode(uint8_t * BitStream, size_t *size, uint8_t invert)
        return bestErr;
 }
 
        return bestErr;
 }
 

+uint32_t manchesterEncode2Bytes(uint16_t datain) {
+       uint32_t output = 0;
+       uint8_t curBit = 0;
+       for (uint8_t i=0; i<16; i++) {
+               curBit = (datain >> (15-i) & 1);
+               output |= (1<<(((15-i)*2)+curBit));
+       }
+       return output;
+}
+

 //by marshmellow
 //encode binary data into binary manchester 
 int ManchesterEncode(uint8_t *BitStream, size_t size)
 //by marshmellow
 //encode binary data into binary manchester 
 int ManchesterEncode(uint8_t *BitStream, size_t size)


@@ -369,19 +393,21 @@ size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow
        if (fclow==0) fclow=8;
        //set the threshold close to 0 (graph) or 128 std to avoid static
        uint8_t threshold_value = 123; 
        if (fclow==0) fclow=8;
        //set the threshold close to 0 (graph) or 128 std to avoid static
        uint8_t threshold_value = 123; 

-
+       size_t preLastSample = 0;
+       size_t LastSample = 0;
+       size_t currSample = 0;

        // sync to first lo-hi transition, and threshold
 
        // Need to threshold first sample
        // sync to first lo-hi transition, and threshold
 
        // Need to threshold first sample

-
-       if(dest[0] < threshold_value) dest[0] = 0;
+       // skip 160 samples to allow antenna/samples to settle
+       if(dest[160] < threshold_value) dest[0] = 0;

        else dest[0] = 1;
 
        size_t numBits = 0;
        // 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
        else dest[0] = 1;
 
        size_t numBits = 0;
        // 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(idx = 1; idx < size; idx++) {
+       for(idx = 161; idx < size-20; idx++) {

                // threshold current value
 
                if (dest[idx] < threshold_value) dest[idx] = 0;
                // threshold current value
 
                if (dest[idx] < threshold_value) dest[idx] = 0;


@@ -389,13 +415,22 @@ size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow
 
                // Check for 0->1 transition
                if (dest[idx-1] < dest[idx]) { // 0 -> 1 transition
 
                // Check for 0->1 transition
                if (dest[idx-1] < dest[idx]) { // 0 -> 1 transition

-                       if ((idx-last_transition)<(fclow-2)){            //0-5 = garbage noise
+                       preLastSample = LastSample;
+                       LastSample = currSample;
+                       currSample = idx-last_transition;
+                       if (currSample < (fclow-2)){            //0-5 = garbage noise (or 0-3)

                                //do nothing with extra garbage
                                //do nothing with extra garbage

-                       } else if ((idx-last_transition) < (fchigh-1)) { //6-8 = 8 waves
+                       } else if (currSample < (fchigh-1)) { //6-8 = 8 sample waves  or 3-6 = 5
+                               if (LastSample > (fchigh-2) && (preLastSample < (fchigh-1) || preLastSample     == 0 )){
+                                       dest[numBits-1]=1;  //correct previous 9 wave surrounded by 8 waves
+                               }

                                dest[numBits++]=1;
                                dest[numBits++]=1;

-                       } else if ((idx-last_transition) > (fchigh+1) && !numBits) { //12 + and first bit = garbage 
+
+                       } else if (currSample > (fchigh) && !numBits) { //12 + and first bit = garbage 

                                //do nothing with beginning garbage
                                //do nothing with beginning garbage

-                       } else {                                         //9+ = 10 waves
+                       } else if (currSample == (fclow+1) && LastSample == (fclow-1)) { // had a 7 then a 9 should be two 8's
+                               dest[numBits++]=1;
+                       } else {                                         //9+ = 10 sample waves

                                dest[numBits++]=0;
                        }
                        last_transition = idx;
                                dest[numBits++]=0;
                        }
                        last_transition = idx;


@@ -418,19 +453,8 @@ size_t aggregate_bits(uint8_t *dest, size_t size, uint8_t rfLen,
                
                //if lastval was 1, we have a 1->0 crossing
                if (dest[idx-1]==1) {
                
                //if lastval was 1, we have a 1->0 crossing
                if (dest[idx-1]==1) {

-                       if (!numBits && n < rfLen/fclow) {
-                               n=0;
-                               lastval = dest[idx];
-                               continue;
-                       }

                        n = (n * fclow + rfLen/2) / rfLen;
                } else {// 0->1 crossing 
                        n = (n * fclow + rfLen/2) / rfLen;
                } else {// 0->1 crossing 

-                       //test first bitsample too small
-                       if (!numBits && n < rfLen/fchigh) {
-                               n=0;
-                               lastval = dest[idx];
-                               continue;
-                       }

                        n = (n * fchigh + rfLen/2) / rfLen; 
                }
                if (n == 0) n = 1;
                        n = (n * fchigh + rfLen/2) / rfLen; 
                }
                if (n == 0) n = 1;


@@ -452,6 +476,7 @@ size_t aggregate_bits(uint8_t *dest, size_t size, uint8_t rfLen,
        }
        return numBits;
 }
        }
        return numBits;
 }

+

 //by marshmellow  (from holiman's base)
 // full fsk demod from GraphBuffer wave to decoded 1s and 0s (no mandemod)
 int fskdemod(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t invert, uint8_t fchigh, uint8_t fclow)
 //by marshmellow  (from holiman's base)
 // full fsk demod from GraphBuffer wave to decoded 1s and 0s (no mandemod)
 int fskdemod(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t invert, uint8_t fchigh, uint8_t fclow)


@@ -526,7 +551,7 @@ int ParadoxdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, ui
        return (int)startIdx;
 }
 
        return (int)startIdx;
 }
 

-uint32_t bytebits_to_byte(uint8_t* src, size_t numbits)
+uint32_t bytebits_to_byte(uint8_t *src, size_t numbits)

 {
        uint32_t num = 0;
        for(int i = 0 ; i < numbits ; i++)
 {
        uint32_t num = 0;
        for(int i = 0 ; i < numbits ; i++)


@@ -537,6 +562,17 @@ uint32_t bytebits_to_byte(uint8_t* src, size_t numbits)
        return num;
 }
 
        return num;
 }
 

+//least significant bit first
+uint32_t bytebits_to_byteLSBF(uint8_t *src, size_t numbits)
+{
+       uint32_t num = 0;
+       for(int i = 0 ; i < numbits ; i++)
+       {
+               num = (num << 1) | *(src + (numbits-(i+1)));
+       }
+       return num;
+}
+

 int IOdemodFSK(uint8_t *dest, size_t size)
 {
        if (justNoise(dest, size)) return -1;
 int IOdemodFSK(uint8_t *dest, size_t size)
 {
        if (justNoise(dest, size)) return -1;


@@ -565,11 +601,30 @@ int IOdemodFSK(uint8_t *dest, size_t size)
                return (int) startIdx;
        }
        return -5;
                return (int) startIdx;
        }
        return -5;

+} 
+
+// by marshmellow
+// find viking preamble 0xF200 in already demoded data
+int VikingDemod_AM(uint8_t *dest, size_t *size) {
+       //make sure buffer has data
+       if (*size < 64*2) return -2;
+
+       size_t startIdx = 0;
+       uint8_t preamble[] = {1,1,1,1,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
+       uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
+       if (errChk == 0) return -4; //preamble not found
+       uint32_t checkCalc = bytebits_to_byte(dest+startIdx,8) ^ bytebits_to_byte(dest+startIdx+8,8) ^ bytebits_to_byte(dest+startIdx+16,8)
+           ^ bytebits_to_byte(dest+startIdx+24,8) ^ bytebits_to_byte(dest+startIdx+32,8) ^ bytebits_to_byte(dest+startIdx+40,8) 
+           ^ bytebits_to_byte(dest+startIdx+48,8) ^ bytebits_to_byte(dest+startIdx+56,8);
+       if ( checkCalc != 0xA8 ) return -5;
+       if (*size != 64) return -6;
+       //return start position
+       return (int) startIdx;

 }
 
 // by marshmellow
 // takes a array of binary values, start position, length of bits per parity (includes parity bit),
 }
 
 // by marshmellow
 // takes a array of binary values, start position, length of bits per parity (includes parity bit),

-//   Parity Type (1 for odd 0 for even), and binary Length (length to run) 
+//   Parity Type (1 for odd; 0 for even; 2 Always 1's), and binary Length (length to run) 

 size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t pType, size_t bLen)
 {
        uint32_t parityWd = 0;
 size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t pType, size_t bLen)
 {
        uint32_t parityWd = 0;


@@ -579,9 +634,13 @@ size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t p
                        parityWd = (parityWd << 1) | BitStream[startIdx+word+bit];
                        BitStream[j++] = (BitStream[startIdx+word+bit]);
                }
                        parityWd = (parityWd << 1) | BitStream[startIdx+word+bit];
                        BitStream[j++] = (BitStream[startIdx+word+bit]);
                }

-               j--;
+               j--; // overwrite parity with next data

                // if parity fails then return 0
                // if parity fails then return 0

-               if (parityTest(parityWd, pLen, pType) == 0) return -1;
+               if (pType == 2) { // then marker bit which should be a 1
+                       if (!BitStream[j]) return 0;
+               } else {
+                       if (parityTest(parityWd, pLen, pType) == 0) return 0;                   
+               }

                bitCnt+=(pLen-1);
                parityWd = 0;
        }
                bitCnt+=(pLen-1);
                parityWd = 0;
        }


@@ -590,6 +649,21 @@ size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t p
        return bitCnt;
 }
 
        return bitCnt;
 }
 

+// Ask/Biphase Demod then try to locate an ISO 11784/85 ID
+// BitStream must contain previously askrawdemod and biphasedemoded data
+int FDXBdemodBI(uint8_t *dest, size_t *size)
+{
+       //make sure buffer has enough data
+       if (*size < 128) return -1;
+
+       size_t startIdx = 0;
+       uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,1};
+
+       uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
+       if (errChk == 0) return -2; //preamble not found
+       return (int)startIdx;
+}
+

 // by marshmellow
 // FSK Demod then try to locate an AWID ID
 int AWIDdemodFSK(uint8_t *dest, size_t *size)
 // by marshmellow
 // FSK Demod then try to locate an AWID ID
 int AWIDdemodFSK(uint8_t *dest, size_t *size)


@@ -612,7 +686,7 @@ int AWIDdemodFSK(uint8_t *dest, size_t *size)
 }
 
 // by marshmellow
 }
 
 // by marshmellow

-// FSK Demod then try to locate an Farpointe Data (pyramid) ID
+// FSK Demod then try to locate a Farpointe Data (pyramid) ID

 int PyramiddemodFSK(uint8_t *dest, size_t *size)
 {
        //make sure buffer has data
 int PyramiddemodFSK(uint8_t *dest, size_t *size)
 {
        //make sure buffer has data


@@ -637,22 +711,21 @@ int PyramiddemodFSK(uint8_t *dest, size_t *size)
 // to detect a wave that has heavily clipped (clean) samples
 uint8_t DetectCleanAskWave(uint8_t dest[], size_t size, uint8_t high, uint8_t low)
 {
 // to detect a wave that has heavily clipped (clean) samples
 uint8_t DetectCleanAskWave(uint8_t dest[], size_t size, uint8_t high, uint8_t low)
 {

-       uint16_t allPeaks=1;
+       bool allArePeaks = true;

        uint16_t cntPeaks=0;
        uint16_t cntPeaks=0;

-       size_t loopEnd = 512+60;
+       size_t loopEnd = 512+160;

        if (loopEnd > size) loopEnd = size;
        if (loopEnd > size) loopEnd = size;

-       for (size_t i=60; i<loopEnd; i++){
+       for (size_t i=160; i<loopEnd; i++){

                if (dest[i]>low && dest[i]<high) 
                if (dest[i]>low && dest[i]<high) 

-                       allPeaks=0;
+                       allArePeaks = false;

                else
                        cntPeaks++;
        }
                else
                        cntPeaks++;
        }

-       if (allPeaks == 0){
-               if (cntPeaks > 300) return 1;
+       if (!allArePeaks){
+               if (cntPeaks > 300) return true;

        }
        }

-       return allPeaks;
+       return allArePeaks;

 }
 }

-

 // by marshmellow
 // to help detect clocks on heavily clipped samples
 // based on count of low to low
 // by marshmellow
 // to help detect clocks on heavily clipped samples
 // based on count of low to low


@@ -660,7 +733,7 @@ int DetectStrongAskClock(uint8_t dest[], size_t size, uint8_t high, uint8_t low)
 {
        uint8_t fndClk[] = {8,16,32,40,50,64,128};
        size_t startwave;
 {
        uint8_t fndClk[] = {8,16,32,40,50,64,128};
        size_t startwave;

-       size_t i = 0;
+       size_t i = 100;

        size_t minClk = 255;
                // get to first full low to prime loop and skip incomplete first pulse
        while ((dest[i] < high) && (i < size))
        size_t minClk = 255;
                // get to first full low to prime loop and skip incomplete first pulse
        while ((dest[i] < high) && (i < size))


@@ -683,6 +756,7 @@ int DetectStrongAskClock(uint8_t dest[], size_t size, uint8_t high, uint8_t low)
                        minClk = i - startwave;
        }
        // set clock
                        minClk = i - startwave;
        }
        // set clock

+       //prnt("minClk: %d",minClk);

        for (uint8_t clkCnt = 0; clkCnt<7; clkCnt++) {
                if (minClk >= fndClk[clkCnt]-(fndClk[clkCnt]/8) && minClk <= fndClk[clkCnt]+1)
                        return fndClk[clkCnt];
        for (uint8_t clkCnt = 0; clkCnt<7; clkCnt++) {
                if (minClk >= fndClk[clkCnt]-(fndClk[clkCnt]/8) && minClk <= fndClk[clkCnt]+1)
                        return fndClk[clkCnt];


@@ -700,8 +774,8 @@ int DetectASKClock(uint8_t dest[], size_t size, int *clock, int maxErr)
        uint8_t clk[] = {255,8,16,32,40,50,64,100,128,255};
        uint8_t clkEnd = 9;
        uint8_t loopCnt = 255;  //don't need to loop through entire array...
        uint8_t clk[] = {255,8,16,32,40,50,64,100,128,255};
        uint8_t clkEnd = 9;
        uint8_t loopCnt = 255;  //don't need to loop through entire array...

-       if (size <= loopCnt) return -1; //not enough samples
-
+       if (size <= loopCnt+60) return -1; //not enough samples
+       size -= 60; //sometimes there is a strange end wave - filter out this....

        //if we already have a valid clock
        uint8_t clockFnd=0;
        for (;i<clkEnd;++i)
        //if we already have a valid clock
        uint8_t clockFnd=0;
        for (;i<clkEnd;++i)


@@ -726,7 +800,6 @@ int DetectASKClock(uint8_t dest[], size_t size, int *clock, int maxErr)
                        }
                }
        }
                        }
                }
        }

-       

        uint8_t ii;
        uint8_t clkCnt, tol = 0;
        uint16_t bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000,1000};
        uint8_t ii;
        uint8_t clkCnt, tol = 0;
        uint16_t bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000,1000};


@@ -768,7 +841,7 @@ int DetectASKClock(uint8_t dest[], size_t size, int *clock, int maxErr)
                        }
                        //if we found no errors then we can stop here and a low clock (common clocks)
                        //  this is correct one - return this clock
                        }
                        //if we found no errors then we can stop here and a low clock (common clocks)
                        //  this is correct one - return this clock

-                                       //PrintAndLog("DEBUG: clk %d, err %d, ii %d, i %d",clk[clkCnt],errCnt,ii,i);
+                                       //prnt("DEBUG: clk %d, err %d, ii %d, i %d",clk[clkCnt],errCnt,ii,i);

                        if(errCnt==0 && clkCnt<7) { 
                                if (!clockFnd) *clock = clk[clkCnt];
                                return ii;
                        if(errCnt==0 && clkCnt<7) { 
                                if (!clockFnd) *clock = clk[clkCnt];
                                return ii;


@@ -804,7 +877,7 @@ int DetectPSKClock(uint8_t dest[], size_t size, int clock)
        uint8_t clk[]={255,16,32,40,50,64,100,128,255}; //255 is not a valid clock
        uint16_t loopCnt = 4096;  //don't need to loop through entire array...
        if (size == 0) return 0;
        uint8_t clk[]={255,16,32,40,50,64,100,128,255}; //255 is not a valid clock
        uint16_t loopCnt = 4096;  //don't need to loop through entire array...
        if (size == 0) return 0;

-       if (size<loopCnt) loopCnt = size;
+       if (size<loopCnt) loopCnt = size-20;

 
        //if we already have a valid clock quit
        size_t i=1;
 
        //if we already have a valid clock quit
        size_t i=1;


@@ -818,17 +891,17 @@ int DetectPSKClock(uint8_t dest[], size_t size, int clock)
        uint16_t peaksdet[]={0,0,0,0,0,0,0,0,0};
        fc = countFC(dest, size, 0);
        if (fc!=2 && fc!=4 && fc!=8) return -1;
        uint16_t peaksdet[]={0,0,0,0,0,0,0,0,0};
        fc = countFC(dest, size, 0);
        if (fc!=2 && fc!=4 && fc!=8) return -1;

-       //PrintAndLog("DEBUG: FC: %d",fc);
+       //prnt("DEBUG: FC: %d",fc);

 
        //find first full wave
 
        //find first full wave

-       for (i=0; i<loopCnt; i++){
+       for (i=160; i<loopCnt; i++){

                if (dest[i] < dest[i+1] && dest[i+1] >= dest[i+2]){
                        if (waveStart == 0) {
                                waveStart = i+1;
                if (dest[i] < dest[i+1] && dest[i+1] >= dest[i+2]){
                        if (waveStart == 0) {
                                waveStart = i+1;

-                               //PrintAndLog("DEBUG: waveStart: %d",waveStart);
+                               //prnt("DEBUG: waveStart: %d",waveStart);

                        } else {
                                waveEnd = i+1;
                        } else {
                                waveEnd = i+1;

-                               //PrintAndLog("DEBUG: waveEnd: %d",waveEnd);
+                               //prnt("DEBUG: waveEnd: %d",waveEnd);

                                waveLenCnt = waveEnd-waveStart;
                                if (waveLenCnt > fc){
                                        firstFullWave = waveStart;
                                waveLenCnt = waveEnd-waveStart;
                                if (waveLenCnt > fc){
                                        firstFullWave = waveStart;


@@ -839,7 +912,7 @@ int DetectPSKClock(uint8_t dest[], size_t size, int clock)
                        }
                }
        }
                        }
                }
        }

-       //PrintAndLog("DEBUG: firstFullWave: %d, waveLen: %d",firstFullWave,fullWaveLen);
+       //prnt("DEBUG: firstFullWave: %d, waveLen: %d",firstFullWave,fullWaveLen);

        
        //test each valid clock from greatest to smallest to see which lines up
        for(clkCnt=7; clkCnt >= 1 ; clkCnt--){
        
        //test each valid clock from greatest to smallest to see which lines up
        for(clkCnt=7; clkCnt >= 1 ; clkCnt--){


@@ -847,7 +920,7 @@ int DetectPSKClock(uint8_t dest[], size_t size, int clock)
                waveStart = 0;
                errCnt=0;
                peakcnt=0;
                waveStart = 0;
                errCnt=0;
                peakcnt=0;

-               //PrintAndLog("DEBUG: clk: %d, lastClkBit: %d",clk[clkCnt],lastClkBit);
+               //prnt("DEBUG: clk: %d, lastClkBit: %d",clk[clkCnt],lastClkBit);

 
                for (i = firstFullWave+fullWaveLen-1; i < loopCnt-2; i++){
                        //top edge of wave = start of new wave 
 
                for (i = firstFullWave+fullWaveLen-1; i < loopCnt-2; i++){
                        //top edge of wave = start of new wave 


@@ -860,7 +933,7 @@ int DetectPSKClock(uint8_t dest[], size_t size, int clock)
                                        waveLenCnt = waveEnd-waveStart;
                                        if (waveLenCnt > fc){ 
                                                //if this wave is a phase shift
                                        waveLenCnt = waveEnd-waveStart;
                                        if (waveLenCnt > fc){ 
                                                //if this wave is a phase shift

-                                               //PrintAndLog("DEBUG: phase shift at: %d, len: %d, nextClk: %d, ii: %d, fc: %d",waveStart,waveLenCnt,lastClkBit+clk[clkCnt]-tol,ii+1,fc);
+                                               //prnt("DEBUG: phase shift at: %d, len: %d, nextClk: %d, ii: %d, fc: %d",waveStart,waveLenCnt,lastClkBit+clk[clkCnt]-tol,ii+1,fc);

                                                if (i+1 >= lastClkBit + clk[clkCnt] - tol){ //should be a clock bit
                                                        peakcnt++;
                                                        lastClkBit+=clk[clkCnt];
                                                if (i+1 >= lastClkBit + clk[clkCnt] - tol){ //should be a clock bit
                                                        peakcnt++;
                                                        lastClkBit+=clk[clkCnt];


@@ -889,11 +962,40 @@ int DetectPSKClock(uint8_t dest[], size_t size, int clock)
                if (peaksdet[i] > peaksdet[best]) {
                        best = i;
                }
                if (peaksdet[i] > peaksdet[best]) {
                        best = i;
                }

-               //PrintAndLog("DEBUG: Clk: %d, peaks: %d, errs: %d, bestClk: %d",clk[iii],peaksdet[iii],bestErr[iii],clk[best]);
+               //prnt("DEBUG: Clk: %d, peaks: %d, errs: %d, bestClk: %d",clk[iii],peaksdet[iii],bestErr[iii],clk[best]);

        }
        return clk[best];
 }
 
        }
        return clk[best];
 }
 

+int DetectStrongNRZClk(uint8_t *dest, size_t size, int peak, int low){
+       //find shortest transition from high to low
+       size_t i = 0;
+       size_t transition1 = 0;
+       int lowestTransition = 255;
+       bool lastWasHigh = false;
+
+       //find first valid beginning of a high or low wave
+       while ((dest[i] >= peak || dest[i] <= low) && (i < size))
+               ++i;
+       while ((dest[i] < peak && dest[i] > low) && (i < size))
+               ++i;
+       lastWasHigh = (dest[i] >= peak);
+
+       if (i==size) return 0;
+       transition1 = i;
+
+       for (;i < size; i++) {
+               if ((dest[i] >= peak && !lastWasHigh) || (dest[i] <= low && lastWasHigh)) {
+                       lastWasHigh = (dest[i] >= peak);
+                       if (i-transition1 < lowestTransition) lowestTransition = i-transition1;
+                       transition1 = i;
+               }
+       }
+       //prnt("DEBUG: LowestTrs: %d",lowestTransition);
+       if (lowestTransition == 255) lowestTransition = 0;
+       return lowestTransition;
+}
+

 //by marshmellow
 //detect nrz clock by reading #peaks vs no peaks(or errors)
 int DetectNRZClock(uint8_t dest[], size_t size, int clock)
 //by marshmellow
 //detect nrz clock by reading #peaks vs no peaks(or errors)
 int DetectNRZClock(uint8_t dest[], size_t size, int clock)


@@ -902,8 +1004,7 @@ int DetectNRZClock(uint8_t dest[], size_t size, int clock)
        uint8_t clk[]={8,16,32,40,50,64,100,128,255};
        size_t loopCnt = 4096;  //don't need to loop through entire array...
        if (size == 0) return 0;
        uint8_t clk[]={8,16,32,40,50,64,100,128,255};
        size_t loopCnt = 4096;  //don't need to loop through entire array...
        if (size == 0) return 0;

-       if (size<loopCnt) loopCnt = size;
-
+       if (size<loopCnt) loopCnt = size-20;

        //if we already have a valid clock quit
        for (; i < 8; ++i)
                if (clk[i] == clock) return clock;
        //if we already have a valid clock quit
        for (; i < 8; ++i)
                if (clk[i] == clock) return clock;


@@ -912,38 +1013,82 @@ int DetectNRZClock(uint8_t dest[], size_t size, int clock)
        int peak, low;
        if (getHiLo(dest, loopCnt, &peak, &low, 75, 75) < 1) return 0;
 
        int peak, low;
        if (getHiLo(dest, loopCnt, &peak, &low, 75, 75) < 1) return 0;
 

-       //PrintAndLog("DEBUG: peak: %d, low: %d",peak,low);
+       int lowestTransition = DetectStrongNRZClk(dest, size-20, peak, low);

        size_t ii;
        uint8_t clkCnt;
        uint8_t tol = 0;
        size_t ii;
        uint8_t clkCnt;
        uint8_t tol = 0;

-       uint16_t peakcnt=0;
-       uint16_t peaksdet[]={0,0,0,0,0,0,0,0};
-       uint16_t maxPeak=0;
+       uint16_t smplCnt = 0;
+       int16_t peakcnt = 0;
+       int16_t peaksdet[] = {0,0,0,0,0,0,0,0};
+       uint16_t maxPeak = 255;
+       bool firstpeak = false;

        //test for large clipped waves
        for (i=0; i<loopCnt; i++){
                if (dest[i] >= peak || dest[i] <= low){
        //test for large clipped waves
        for (i=0; i<loopCnt; i++){
                if (dest[i] >= peak || dest[i] <= low){

-                       peakcnt++;
+                       if (!firstpeak) continue;
+                       smplCnt++;

                } else {
                } else {

-                       if (peakcnt>0 && maxPeak < peakcnt){
-                               maxPeak = peakcnt;
+                       firstpeak=true;
+                       if (smplCnt > 6 ){
+                               if (maxPeak > smplCnt){
+                                       maxPeak = smplCnt;
+                                       //prnt("maxPk: %d",maxPeak);
+                               }
+                               peakcnt++;
+                               //prnt("maxPk: %d, smplCnt: %d, peakcnt: %d",maxPeak,smplCnt,peakcnt);
+                               smplCnt=0;

                        }
                        }

-                       peakcnt=0;

                }
        }
                }
        }

+       bool errBitHigh = 0;
+       bool bitHigh = 0;
+       uint8_t ignoreCnt = 0;
+       uint8_t ignoreWindow = 4;
+       bool lastPeakHigh = 0;
+       int lastBit = 0; 

        peakcnt=0;
        //test each valid clock from smallest to greatest to see which lines up
        for(clkCnt=0; clkCnt < 8; ++clkCnt){
        peakcnt=0;
        //test each valid clock from smallest to greatest to see which lines up
        for(clkCnt=0; clkCnt < 8; ++clkCnt){

-               //ignore clocks smaller than largest peak
-               if (clk[clkCnt]<maxPeak) continue;
-
+               //ignore clocks smaller than smallest peak
+               if (clk[clkCnt] < maxPeak - (clk[clkCnt]/4)) continue;

                //try lining up the peaks by moving starting point (try first 256)
                //try lining up the peaks by moving starting point (try first 256)

-               for (ii=0; ii< loopCnt; ++ii){
+               for (ii=20; ii < loopCnt; ++ii){

                        if ((dest[ii] >= peak) || (dest[ii] <= low)){
                        if ((dest[ii] >= peak) || (dest[ii] <= low)){

-                               peakcnt=0;
-                               // now that we have the first one lined up test rest of wave array
-                               for (i=0; i < ((int)((size-ii-tol)/clk[clkCnt])-1); ++i){
-                                       if (dest[ii+(i*clk[clkCnt])]>=peak || dest[ii+(i*clk[clkCnt])]<=low){
-                                               peakcnt++;
+                               peakcnt = 0;
+                               bitHigh = false;
+                               ignoreCnt = 0;
+                               lastBit = ii-clk[clkCnt]; 
+                               //loop through to see if this start location works
+                               for (i = ii; i < size-20; ++i) {
+                                       //if we are at a clock bit
+                                       if ((i >= lastBit + clk[clkCnt] - tol) && (i <= lastBit + clk[clkCnt] + tol)) {
+                                               //test high/low
+                                               if (dest[i] >= peak || dest[i] <= low) {
+                                                       //if same peak don't count it
+                                                       if ((dest[i] >= peak && !lastPeakHigh) || (dest[i] <= low && lastPeakHigh)) {
+                                                               peakcnt++;
+                                                       }
+                                                       lastPeakHigh = (dest[i] >= peak);
+                                                       bitHigh = true;
+                                                       errBitHigh = false;
+                                                       ignoreCnt = ignoreWindow;
+                                                       lastBit += clk[clkCnt];
+                                               } else if (i == lastBit + clk[clkCnt] + tol) {
+                                                       lastBit += clk[clkCnt];
+                                               }
+                                       //else if not a clock bit and no peaks
+                                       } else if (dest[i] < peak && dest[i] > low){
+                                               if (ignoreCnt==0){
+                                                       bitHigh=false;
+                                                       if (errBitHigh==true) peakcnt--;
+                                                       errBitHigh=false;
+                                               } else {
+                                                       ignoreCnt--;
+                                               }
+                                               // else if not a clock bit but we have a peak
+                                       } else if ((dest[i]>=peak || dest[i]<=low) && (!bitHigh)) {
+                                               //error bar found no clock...
+                                               errBitHigh=true;

                                        }
                                }
                                if(peakcnt>peaksdet[clkCnt]) {
                                        }
                                }
                                if(peakcnt>peaksdet[clkCnt]) {


@@ -955,11 +1100,16 @@ int DetectNRZClock(uint8_t dest[], size_t size, int clock)
        int iii=7;
        uint8_t best=0;
        for (iii=7; iii > 0; iii--){
        int iii=7;
        uint8_t best=0;
        for (iii=7; iii > 0; iii--){

-               if (peaksdet[iii] > peaksdet[best]){
+               if ((peaksdet[iii] >= (peaksdet[best]-1)) && (peaksdet[iii] <= peaksdet[best]+1) && lowestTransition) {
+                       if (clk[iii] > (lowestTransition - (clk[iii]/8)) && clk[iii] < (lowestTransition + (clk[iii]/8))) {
+                               best = iii;
+                       }
+               } else if (peaksdet[iii] > peaksdet[best]){

                        best = iii;
                }
                        best = iii;
                }

-               //PrintAndLog("DEBUG: Clk: %d, peaks: %d, errs: %d, bestClk: %d",clk[iii],peaksdet[iii],bestErr[iii],clk[best]);
+               //prnt("DEBUG: Clk: %d, peaks: %d, maxPeak: %d, bestClk: %d, lowestTrs: %d",clk[iii],peaksdet[iii],maxPeak, clk[best], lowestTransition);

        }
        }

+

        return clk[best];
 }
 
        return clk[best];
 }
 


@@ -1003,182 +1153,53 @@ void psk2TOpsk1(uint8_t *BitStream, size_t size)
 int indala26decode(uint8_t *bitStream, size_t *size, uint8_t *invert)
 {
        //26 bit 40134 format  (don't know other formats)
 int indala26decode(uint8_t *bitStream, size_t *size, uint8_t *invert)
 {
        //26 bit 40134 format  (don't know other formats)

-       int i;
-       int long_wait=29;//29 leading zeros in format
-       int start;
-       int first = 0;
-       int first2 = 0;
-       int bitCnt = 0;
-       int ii;
-       // Finding the start of a UID
-       for (start = 0; start <= *size - 250; start++) {
-               first = bitStream[start];
-               for (i = start; i < start + long_wait; i++) {
-                       if (bitStream[i] != first) {
-                               break;
-                       }
-               }
-               if (i == (start + long_wait)) {
-                       break;
-               }
-       }
-       if (start == *size - 250 + 1) {
-               // did not find start sequence
-               return -1;
-       }
-       // Inverting signal if needed
-       if (first == 1) {
-               for (i = start; i < *size; i++) {
-                       bitStream[i] = !bitStream[i];
-               }
-               *invert = 1;
-       }else *invert=0;
-
-       int iii;
-       //found start once now test length by finding next one
-       for (ii=start+29; ii <= *size - 250; ii++) {
-               first2 = bitStream[ii];
-               for (iii = ii; iii < ii + long_wait; iii++) {
-                       if (bitStream[iii] != first2) {
-                               break;
-                       }
-               }
-               if (iii == (ii + long_wait)) {
-                       break;
-               }
-       }
-       if (ii== *size - 250 + 1){
-               // did not find second start sequence
-               return -2;
-       }
-       bitCnt=ii-start;
+       uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1};
+       uint8_t preamble_i[] = {1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0};
+       size_t startidx = 0; 
+       if (!preambleSearch(bitStream, preamble, sizeof(preamble), size, &startidx)){
+               // if didn't find preamble try again inverting
+               if (!preambleSearch(bitStream, preamble_i, sizeof(preamble_i), size, &startidx)) return -1;
+               *invert ^= 1;
+       } 
+       if (*size != 64 && *size != 224) return -2;
+       if (*invert==1)
+               for (size_t i = startidx; i < *size; i++)
+                       bitStream[i] ^= 1;

 
 

-       // Dumping UID
-       i = start;
-       for (ii = 0; ii < bitCnt; ii++) {
-               bitStream[ii] = bitStream[i++];
-       }
-       *size=bitCnt;
-       return 1;
+       return (int) startidx;

 }
 
 }
 

-// by marshmellow - demodulate NRZ wave (both similar enough)
+// by marshmellow - demodulate NRZ wave

 // peaks invert bit (high=1 low=0) each clock cycle = 1 bit determined by last peak
 // peaks invert bit (high=1 low=0) each clock cycle = 1 bit determined by last peak

-// there probably is a much simpler way to do this.... 
-int nrzRawDemod(uint8_t *dest, size_t *size, int *clk, int *invert, int maxErr)
-{
+int nrzRawDemod(uint8_t *dest, size_t *size, int *clk, int *invert){

        if (justNoise(dest, *size)) return -1;
        *clk = DetectNRZClock(dest, *size, *clk);
        if (*clk==0) return -2;
        size_t i, gLen = 4096;
        if (justNoise(dest, *size)) return -1;
        *clk = DetectNRZClock(dest, *size, *clk);
        if (*clk==0) return -2;
        size_t i, gLen = 4096;

-       if (gLen>*size) gLen = *size;
+       if (gLen>*size) gLen = *size-20;

        int high, low;
        if (getHiLo(dest, gLen, &high, &low, 75, 75) < 1) return -3; //25% fuzz on high 25% fuzz on low
        int high, low;
        if (getHiLo(dest, gLen, &high, &low, 75, 75) < 1) return -3; //25% fuzz on high 25% fuzz on low

-       int lastBit = 0;  //set first clock check
-       size_t iii = 0, bitnum = 0; //bitnum counter
-       uint16_t errCnt = 0, MaxBits = 1000;
-       size_t bestErrCnt = maxErr+1;
-       size_t bestPeakCnt = 0, bestPeakStart = 0;
-       uint8_t bestFirstPeakHigh=0, firstPeakHigh=0, curBit=0, bitHigh=0, errBitHigh=0;
-       uint8_t tol = 1;  //clock tolerance adjust - waves will be accepted as within the clock if they fall + or - this value + clock from last valid wave
-       uint16_t peakCnt=0;
-       uint8_t ignoreWindow=4;
-       uint8_t ignoreCnt=ignoreWindow; //in case of noise near peak
-       //loop to find first wave that works - align to clock
-       for (iii=0; iii < gLen; ++iii){
-               if ((dest[iii]>=high) || (dest[iii]<=low)){
-                       if (dest[iii]>=high) firstPeakHigh=1;
-                       else firstPeakHigh=0;
-                       lastBit=iii-*clk;
-                       peakCnt=0;
-                       errCnt=0;
-                       //loop through to see if this start location works
-                       for (i = iii; i < *size; ++i) {
-                               // if we are at a clock bit
-                               if ((i >= lastBit + *clk - tol) && (i <= lastBit + *clk + tol)) {
-                                       //test high/low
-                                       if (dest[i] >= high || dest[i] <= low) {
-                                               bitHigh = 1;
-                                               peakCnt++;
-                                               errBitHigh = 0;
-                                               ignoreCnt = ignoreWindow;
-                                               lastBit += *clk;
-                                       } else if (i == lastBit + *clk + tol) {
-                                               lastBit += *clk;
-                                       }
-                               //else if no bars found
-                               } else if (dest[i] < high && dest[i] > low){
-                                       if (ignoreCnt==0){
-                                               bitHigh=0;
-                                               if (errBitHigh==1) errCnt++;
-                                               errBitHigh=0;
-                                       } else {
-                                               ignoreCnt--;
-                                       }
-                               } else if ((dest[i]>=high || dest[i]<=low) && (bitHigh==0)) {
-                                       //error bar found no clock...
-                                       errBitHigh=1;
-                               }
-                               if (((i-iii) / *clk)>=MaxBits) break;
-                       }
-                       //we got more than 64 good bits and not all errors
-                       if (((i-iii) / *clk) > 64 && (errCnt <= (maxErr))) {
-                               //possible good read
-                               if (!errCnt || peakCnt > bestPeakCnt){
-                                       bestFirstPeakHigh=firstPeakHigh;
-                                       bestErrCnt = errCnt;
-                                       bestPeakCnt = peakCnt;
-                                       bestPeakStart = iii;
-                                       if (!errCnt) break;  //great read - finish
-                               }
-                       }
-               }
+       
+       uint8_t bit=0;
+       //convert wave samples to 1's and 0's
+       for(i=20; i < *size-20; i++){
+               if (dest[i] >= high) bit = 1;
+               if (dest[i] <= low)  bit = 0;
+               dest[i] = bit;

        }
        }

-       //PrintAndLog("DEBUG: bestErrCnt: %d, maxErr: %d, bestStart: %d, bestPeakCnt: %d, bestPeakStart: %d",bestErrCnt,maxErr,bestStart,bestPeakCnt,bestPeakStart);
-       if (bestErrCnt > maxErr) return bestErrCnt;             
-
-       //best run is good enough set to best run and set overwrite BinStream
-       lastBit = bestPeakStart - *clk;
-       memset(dest, bestFirstPeakHigh^1, bestPeakStart / *clk);
-       bitnum += (bestPeakStart / *clk);
-       for (i = bestPeakStart; i < *size; ++i) {
-               // if expecting a clock bit
-               if ((i >= lastBit + *clk - tol) && (i <= lastBit + *clk + tol)) {
-                       // test high/low
-                       if (dest[i] >= high || dest[i] <= low) {
-                               peakCnt++;
-                               bitHigh = 1;
-                               errBitHigh = 0;
-                               ignoreCnt = ignoreWindow;
-                               curBit = *invert;
-                               if (dest[i] >= high) curBit ^= 1;
-                               dest[bitnum++] = curBit;
-                               lastBit += *clk;
-                       //else no bars found in clock area
-                       } else if (i == lastBit + *clk + tol) {
-                               dest[bitnum++] = curBit;
-                               lastBit += *clk;
-                       }
-               //else if no bars found
-               } else if (dest[i] < high && dest[i] > low){
-                       if (ignoreCnt == 0){
-                               bitHigh = 0;
-                               if (errBitHigh == 1){
-                                       dest[bitnum++] = 7;
-                                       errCnt++;
-                               }
-                               errBitHigh=0;
-                       } else {
-                               ignoreCnt--;
-                       }
-               } else if ((dest[i] >= high || dest[i] <= low) && (bitHigh == 0)) {
-                       //error bar found no clock...
-                       errBitHigh=1;
+       //now demod based on clock (rf/32 = 32 1's for one 1 bit, 32 0's for one 0 bit) 
+       size_t lastBit = 0;
+       size_t numBits = 0;
+       for(i=21; i < *size-20; i++) {
+               //if transition detected or large number of same bits - store the passed bits
+               if (dest[i] != dest[i-1] || (i-lastBit) == (10 * *clk)) {
+                       memset(dest+numBits, dest[i-1] ^ *invert, (i - lastBit + (*clk/4)) / *clk);
+                       numBits += (i - lastBit + (*clk/4)) / *clk;
+                       lastBit = i-1;

                }
                }

-               if (bitnum >= MaxBits) break;

        }
        }

-       *size = bitnum;
-       return bestErrCnt;
+       *size = numBits;
+       return 0;

 }
 
 //by marshmellow
 }
 
 //by marshmellow


@@ -1196,18 +1217,18 @@ uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fc
        size_t i;
        if (size == 0) return 0;
 
        size_t i;
        if (size == 0) return 0;
 

-       uint8_t fcTol = (uint8_t)(0.5+(float)(fcHigh-fcLow)/2);
+       uint8_t fcTol = ((fcHigh*100 - fcLow*100)/2 + 50)/100; //(uint8_t)(0.5+(float)(fcHigh-fcLow)/2);

        rfLensFnd=0;
        fcCounter=0;
        rfCounter=0;
        firstBitFnd=0;
        //PrintAndLog("DEBUG: fcTol: %d",fcTol);
        rfLensFnd=0;
        fcCounter=0;
        rfCounter=0;
        firstBitFnd=0;
        //PrintAndLog("DEBUG: fcTol: %d",fcTol);

-       // prime i to first up transition
-       for (i = 1; i < size-1; i++)
+       // prime i to first peak / up transition
+       for (i = 160; i < size-20; i++)

                if (BitStream[i] > BitStream[i-1] && BitStream[i]>=BitStream[i+1])
                        break;
 
                if (BitStream[i] > BitStream[i-1] && BitStream[i]>=BitStream[i+1])
                        break;
 

-       for (; i < size-1; i++){
+       for (; i < size-20; i++){

                fcCounter++;
                rfCounter++;
 
                fcCounter++;
                rfCounter++;
 


@@ -1225,7 +1246,7 @@ uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fc
                        //not the same size as the last wave - start of new bit sequence
                        if (firstBitFnd > 1){ //skip first wave change - probably not a complete bit
                                for (int ii=0; ii<15; ii++){
                        //not the same size as the last wave - start of new bit sequence
                        if (firstBitFnd > 1){ //skip first wave change - probably not a complete bit
                                for (int ii=0; ii<15; ii++){

-                                       if (rfLens[ii] == rfCounter){
+                                       if (rfLens[ii] >= (rfCounter-4) && rfLens[ii] <= (rfCounter+4)){

                                                rfCnts[ii]++;
                                                rfCounter = 0;
                                                break;
                                                rfCnts[ii]++;
                                                rfCounter = 0;
                                                break;


@@ -1247,7 +1268,7 @@ uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fc
        uint8_t rfHighest=15, rfHighest2=15, rfHighest3=15;
 
        for (i=0; i<15; i++){
        uint8_t rfHighest=15, rfHighest2=15, rfHighest3=15;
 
        for (i=0; i<15; i++){

-               //PrintAndLog("DEBUG: RF %d, cnts %d",rfLens[i], rfCnts[i]);
+               //prnt("DEBUG: RF %d, cnts %d",rfLens[i], rfCnts[i]);

                //get highest 2 RF values  (might need to get more values to compare or compare all?)
                if (rfCnts[i]>rfCnts[rfHighest]){
                        rfHighest3=rfHighest2;
                //get highest 2 RF values  (might need to get more values to compare or compare all?)
                if (rfCnts[i]>rfCnts[rfHighest]){
                        rfHighest3=rfHighest2;


@@ -1264,12 +1285,13 @@ uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fc
        //   we could have mistakenly made a 9 a 10 instead of an 8 or visa versa so rfLens could be 1 FC off  
        uint8_t tol1 = fcHigh+1; 
        
        //   we could have mistakenly made a 9 a 10 instead of an 8 or visa versa so rfLens could be 1 FC off  
        uint8_t tol1 = fcHigh+1; 
        

-       //PrintAndLog("DEBUG: hightest: 1 %d, 2 %d, 3 %d",rfLens[rfHighest],rfLens[rfHighest2],rfLens[rfHighest3]);
+       //prnt("DEBUG: hightest: 1 %d, 2 %d, 3 %d",rfLens[rfHighest],rfLens[rfHighest2],rfLens[rfHighest3]);

 
        // loop to find the highest clock that has a remainder less than the tolerance
        //   compare samples counted divided by
 
        // loop to find the highest clock that has a remainder less than the tolerance
        //   compare samples counted divided by

+       // test 128 down to 32 (shouldn't be possible to have fc/10 & fc/8 and rf/16 or less)

        int ii=7;
        int ii=7;

-       for (; ii>=0; ii--){
+       for (; ii>=2; ii--){

                if (rfLens[rfHighest] % clk[ii] < tol1 || rfLens[rfHighest] % clk[ii] > clk[ii]-tol1){
                        if (rfLens[rfHighest2] % clk[ii] < tol1 || rfLens[rfHighest2] % clk[ii] > clk[ii]-tol1){
                                if (rfLens[rfHighest3] % clk[ii] < tol1 || rfLens[rfHighest3] % clk[ii] > clk[ii]-tol1){
                if (rfLens[rfHighest] % clk[ii] < tol1 || rfLens[rfHighest] % clk[ii] > clk[ii]-tol1){
                        if (rfLens[rfHighest2] % clk[ii] < tol1 || rfLens[rfHighest2] % clk[ii] > clk[ii]-tol1){
                                if (rfLens[rfHighest3] % clk[ii] < tol1 || rfLens[rfHighest3] % clk[ii] > clk[ii]-tol1){


@@ -1290,8 +1312,8 @@ uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fc
 //mainly used for FSK field clock detection
 uint16_t countFC(uint8_t *BitStream, size_t size, uint8_t fskAdj)
 {
 //mainly used for FSK field clock detection
 uint16_t countFC(uint8_t *BitStream, size_t size, uint8_t fskAdj)
 {

-       uint8_t fcLens[] = {0,0,0,0,0,0,0,0,0,0};
-       uint16_t fcCnts[] = {0,0,0,0,0,0,0,0,0,0};
+       uint8_t fcLens[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
+       uint16_t fcCnts[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};

        uint8_t fcLensFnd = 0;
        uint8_t lastFCcnt=0;
        uint8_t fcCounter = 0;
        uint8_t fcLensFnd = 0;
        uint8_t lastFCcnt=0;
        uint8_t fcCounter = 0;


@@ -1299,11 +1321,11 @@ uint16_t countFC(uint8_t *BitStream, size_t size, uint8_t fskAdj)
        if (size == 0) return 0;
 
        // prime i to first up transition
        if (size == 0) return 0;
 
        // prime i to first up transition

-       for (i = 1; i < size-1; i++)
+       for (i = 160; i < size-20; i++)

                if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1])
                        break;
 
                if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1])
                        break;
 

-       for (; i < size-1; i++){
+       for (; i < size-20; i++){

                if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1]){
                        // new up transition
                        fcCounter++;
                if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1]){
                        // new up transition
                        fcCounter++;


@@ -1316,14 +1338,14 @@ uint16_t countFC(uint8_t *BitStream, size_t size, uint8_t fskAdj)
                        lastFCcnt = fcCounter;
                        }
                        // find which fcLens to save it to:
                        lastFCcnt = fcCounter;
                        }
                        // find which fcLens to save it to:

-                       for (int ii=0; ii<10; ii++){
+                       for (int ii=0; ii<15; ii++){

                                if (fcLens[ii]==fcCounter){
                                        fcCnts[ii]++;
                                        fcCounter=0;
                                        break;
                                }
                        }
                                if (fcLens[ii]==fcCounter){
                                        fcCnts[ii]++;
                                        fcCounter=0;
                                        break;
                                }
                        }

-                       if (fcCounter>0 && fcLensFnd<10){
+                       if (fcCounter>0 && fcLensFnd<15){

                                //add new fc length 
                                fcCnts[fcLensFnd]++;
                                fcLens[fcLensFnd++]=fcCounter;
                                //add new fc length 
                                fcCnts[fcLensFnd]++;
                                fcLens[fcLensFnd++]=fcCounter;


@@ -1335,11 +1357,11 @@ uint16_t countFC(uint8_t *BitStream, size_t size, uint8_t fskAdj)
                }
        }
        
                }
        }
        

-       uint8_t best1=9, best2=9, best3=9;
+       uint8_t best1=14, best2=14, best3=14;

        uint16_t maxCnt1=0;
        // go through fclens and find which ones are bigest 2  
        uint16_t maxCnt1=0;
        // go through fclens and find which ones are bigest 2  

-       for (i=0; i<10; i++){
-               // PrintAndLog("DEBUG: FC %d, Cnt %d, Errs %d",fcLens[i],fcCnts[i],errCnt);    
+       for (i=0; i<15; i++){
+               //prnt("DEBUG: FC %d, Cnt %d",fcLens[i],fcCnts[i]);    

                // get the 3 best FC values
                if (fcCnts[i]>maxCnt1) {
                        best3=best2;
                // get the 3 best FC values
                if (fcCnts[i]>maxCnt1) {
                        best3=best2;


@@ -1353,6 +1375,7 @@ uint16_t countFC(uint8_t *BitStream, size_t size, uint8_t fskAdj)
                        best3=i;
                }
        }
                        best3=i;
                }
        }

+       if (fcLens[best1]==0) return 0;

        uint8_t fcH=0, fcL=0;
        if (fcLens[best1]>fcLens[best2]){
                fcH=fcLens[best1];
        uint8_t fcH=0, fcL=0;
        if (fcLens[best1]>fcLens[best2]){
                fcH=fcLens[best1];


@@ -1361,11 +1384,13 @@ uint16_t countFC(uint8_t *BitStream, size_t size, uint8_t fskAdj)
                fcH=fcLens[best2];
                fcL=fcLens[best1];
        }
                fcH=fcLens[best2];
                fcL=fcLens[best1];
        }

+       //prnt("DEBUG: dd %d > %d",(size-180)/fcH/3,fcCnts[best1]+fcCnts[best2]);
+       if ((size-180)/fcH/3 > fcCnts[best1]+fcCnts[best2]) return 0; //lots of waves not psk or fsk

 
        // TODO: take top 3 answers and compare to known Field clocks to get top 2
 
        uint16_t fcs = (((uint16_t)fcH)<<8) | fcL;
 
        // TODO: take top 3 answers and compare to known Field clocks to get top 2
 
        uint16_t fcs = (((uint16_t)fcH)<<8) | fcL;

-       // PrintAndLog("DEBUG: Best %d  best2 %d best3 %d",fcLens[best1],fcLens[best2],fcLens[best3]);
+       //prnt("DEBUG: Best %d  best2 %d best3 %d",fcLens[best1],fcLens[best2],fcLens[best3]);

        if (fskAdj) return fcs; 
        return fcLens[best1];
 }
        if (fskAdj) return fcs; 
        return fcLens[best1];
 }


@@ -1378,6 +1403,7 @@ int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert)
        uint16_t loopCnt = 4096;  //don't need to loop through entire array...
        if (*size<loopCnt) loopCnt = *size;
 
        uint16_t loopCnt = 4096;  //don't need to loop through entire array...
        if (*size<loopCnt) loopCnt = *size;
 

+       size_t numBits=0;

        uint8_t curPhase = *invert;
        size_t i, waveStart=1, waveEnd=0, firstFullWave=0, lastClkBit=0;
        uint8_t fc=0, fullWaveLen=0, tol=1;
        uint8_t curPhase = *invert;
        size_t i, waveStart=1, waveEnd=0, firstFullWave=0, lastClkBit=0;
        uint8_t fc=0, fullWaveLen=0, tol=1;


@@ -1394,7 +1420,7 @@ int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert)
                        waveEnd = i+1;
                        //PrintAndLog("DEBUG: waveEnd: %d",waveEnd);
                        waveLenCnt = waveEnd-waveStart;
                        waveEnd = i+1;
                        //PrintAndLog("DEBUG: waveEnd: %d",waveEnd);
                        waveLenCnt = waveEnd-waveStart;

-                       if (waveLenCnt > fc && waveStart > fc){ //not first peak and is a large wave 
+                       if (waveLenCnt > fc && waveStart > fc && !(waveLenCnt > fc+2)){ //not first peak and is a large wave but not out of whack

                                lastAvgWaveVal = avgWaveVal/(waveLenCnt);
                                firstFullWave = waveStart;
                                fullWaveLen=waveLenCnt;
                                lastAvgWaveVal = avgWaveVal/(waveLenCnt);
                                firstFullWave = waveStart;
                                fullWaveLen=waveLenCnt;


@@ -1407,14 +1433,21 @@ int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert)
                }
                avgWaveVal += dest[i+2];
        }
                }
                avgWaveVal += dest[i+2];
        }

+       if (firstFullWave == 0) {
+               // no phase shift detected - could be all 1's or 0's - doesn't matter where we start
+               // so skip a little to ensure we are past any Start Signal
+               firstFullWave = 160;
+               memset(dest, curPhase, firstFullWave / *clock);
+       } else {
+               memset(dest, curPhase^1, firstFullWave / *clock);
+       }
+       //advance bits
+       numBits += (firstFullWave / *clock);
+       //set start of wave as clock align
+       lastClkBit = firstFullWave;

        //PrintAndLog("DEBUG: firstFullWave: %d, waveLen: %d",firstFullWave,fullWaveLen);  
        //PrintAndLog("DEBUG: firstFullWave: %d, waveLen: %d",firstFullWave,fullWaveLen);  

-       lastClkBit = firstFullWave; //set start of wave as clock align

        //PrintAndLog("DEBUG: clk: %d, lastClkBit: %d", *clock, lastClkBit);
        waveStart = 0;
        //PrintAndLog("DEBUG: clk: %d, lastClkBit: %d", *clock, lastClkBit);
        waveStart = 0;

-       size_t numBits=0;
-       //set skipped bits
-       memset(dest, curPhase^1, firstFullWave / *clock);
-       numBits += (firstFullWave / *clock);

        dest[numBits++] = curPhase; //set first read bit
        for (i = firstFullWave + fullWaveLen - 1; i < *size-3; i++){
                //top edge of wave = start of new wave 
        dest[numBits++] = curPhase; //set first read bit
        for (i = firstFullWave + fullWaveLen - 1; i < *size-3; i++){
                //top edge of wave = start of new wave