// at your option, any later version. See the LICENSE.txt file for the text of
// the license.
//-----------------------------------------------------------------------------
-// Low frequency commands
+// Low frequency demod/decode commands
//-----------------------------------------------------------------------------
#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"
+#include "cmdparser.h"
+#include "cmddata.h"
+#define prnt PrintAndLog
+#else
+ uint8_t g_debugMode=0;
+#define prnt dummy
+#endif
+
+uint8_t justNoise(uint8_t *BitStream, size_t size)
+{
+ static const uint8_t THRESHOLD = 123;
+ //test samples are not just noise
+ uint8_t justNoise1 = 1;
+ for(size_t idx=0; idx < size && justNoise1 ;idx++){
+ justNoise1 = BitStream[idx] < THRESHOLD;
+ }
+ return justNoise1;
+}
//by marshmellow
-//takes 1s and 0s and searches for EM410x format - output EM ID
-uint64_t Em410xDecode(uint8_t *BitStream, size_t size)
+//get high and low values of a wave with passed in fuzz factor. also return noise test = 1 for passed or 0 for only noise
+int getHiLo(uint8_t *BitStream, size_t size, int *high, int *low, uint8_t fuzzHi, uint8_t fuzzLo)
{
- //no arguments needed - built this way in case we want this to be a direct call from "data " cmds in the future
- // otherwise could be a void with no arguments
- //set defaults
- int high=0, low=128;
- uint64_t lo=0;
+ *high=0;
+ *low=255;
+ // get high and low thresholds
+ for (size_t i=0; i < size; i++){
+ if (BitStream[i] > *high) *high = BitStream[i];
+ if (BitStream[i] < *low) *low = BitStream[i];
+ }
+ if (*high < 123) return -1; // just noise
+ *high = ((*high-128)*fuzzHi + 12800)/100;
+ *low = ((*low-128)*fuzzLo + 12800)/100;
+ return 1;
+}
- uint32_t i = 0;
- uint32_t initLoopMax = 65;
- if (initLoopMax>size) initLoopMax=size;
+// by marshmellow
+// pass bits to be tested in bits, length bits passed in bitLen, and parity type (even=0 | odd=1) in pType
+// returns 1 if passed
+uint8_t parityTest(uint32_t bits, uint8_t bitLen, uint8_t pType)
+{
+ uint8_t ans = 0;
+ for (uint8_t i = 0; i < bitLen; i++){
+ ans ^= ((bits >> i) & 1);
+ }
+ //PrintAndLog("DEBUG: ans: %d, ptype: %d",ans,pType);
+ return (ans == pType);
+}
+
+// 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; 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 j = 0, bitCnt = 0;
+ for (int word = 0; word < (bLen); word+=pLen){
+ for (int bit=0; bit < pLen; bit++){
+ parityWd = (parityWd << 1) | BitStream[startIdx+word+bit];
+ BitStream[j++] = (BitStream[startIdx+word+bit]);
+ }
+ j--; // overwrite parity with next data
+ // if parity fails then return 0
+ 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;
+ }
+ // if we got here then all the parities passed
+ //return ID start index and size
+ return bitCnt;
+}
+
+// by marshmellow
+// takes a array of binary values, length of bits per parity (includes parity bit),
+// Parity Type (1 for odd; 0 for even; 2 Always 1's), and binary Length (length to run)
+size_t addParity(uint8_t *BitSource, uint8_t *dest, uint8_t sourceLen, uint8_t pLen, uint8_t pType)
+{
+ uint32_t parityWd = 0;
+ size_t j = 0, bitCnt = 0;
+ for (int word = 0; word < sourceLen; word+=pLen-1) {
+ for (int bit=0; bit < pLen-1; bit++){
+ parityWd = (parityWd << 1) | BitSource[word+bit];
+ dest[j++] = (BitSource[word+bit]);
+ }
+ // if parity fails then return 0
+ if (pType == 2) { // then marker bit which should be a 1
+ dest[j++]=1;
+ } else {
+ dest[j++] = parityTest(parityWd, pLen-1, pType) ^ 1;
+ }
+ bitCnt += pLen;
+ parityWd = 0;
+ }
+ // if we got here then all the parities passed
+ //return ID start index and size
+ return bitCnt;
+}
- for (;i < initLoopMax; ++i) //65 samples should be plenty to find high and low values
+uint32_t bytebits_to_byte(uint8_t *src, size_t numbits)
+{
+ uint32_t num = 0;
+ for(int i = 0 ; i < numbits ; i++)
{
- if (BitStream[i] > high)
- high = BitStream[i];
- else if (BitStream[i] < low)
- low = BitStream[i];
+ num = (num << 1) | (*src);
+ src++;
}
- if (((high !=1)||(low !=0))){ //allow only 1s and 0s
- // PrintAndLog("no data found");
- return 0;
+ 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)));
}
- uint8_t parityTest=0;
- // 111111111 bit pattern represent start of frame
- uint8_t frame_marker_mask[] = {1,1,1,1,1,1,1,1,1};
- uint32_t idx = 0;
- uint32_t ii=0;
- uint8_t resetCnt = 0;
- while( (idx + 64) < size) {
- restart:
- // search for a start of frame marker
- if ( memcmp(BitStream+idx, frame_marker_mask, sizeof(frame_marker_mask)) == 0)
- { // frame marker found
- idx+=9;
- for (i=0; i<10;i++){
- for(ii=0; ii<5; ++ii){
- parityTest += BitStream[(i*5)+ii+idx];
- }
- if (parityTest== ((parityTest>>1)<<1)){
- parityTest=0;
- for (ii=0; ii<4;++ii){
- lo=(lo<<1LL)|(BitStream[(i*5)+ii+idx]);
- }
- //PrintAndLog("DEBUG: EM parity passed parity val: %d, i:%d, ii:%d,idx:%d, Buffer: %d%d%d%d%d,lo: %d",parityTest,i,ii,idx,BitStream[idx+ii+(i*5)-5],BitStream[idx+ii+(i*5)-4],BitStream[idx+ii+(i*5)-3],BitStream[idx+ii+(i*5)-2],BitStream[idx+ii+(i*5)-1],lo);
- }else {//parity failed
- //PrintAndLog("DEBUG: EM parity failed parity val: %d, i:%d, ii:%d,idx:%d, Buffer: %d%d%d%d%d",parityTest,i,ii,idx,BitStream[idx+ii+(i*5)-5],BitStream[idx+ii+(i*5)-4],BitStream[idx+ii+(i*5)-3],BitStream[idx+ii+(i*5)-2],BitStream[idx+ii+(i*5)-1]);
- parityTest=0;
- idx-=8;
- if (resetCnt>5)return 0;
- resetCnt++;
- goto restart;//continue;
- }
+ return num;
+}
+
+//by marshmellow
+//search for given preamble in given BitStream and return success=1 or fail=0 and startIndex and length
+uint8_t preambleSearch(uint8_t *BitStream, uint8_t *preamble, size_t pLen, size_t *size, size_t *startIdx)
+{
+ uint8_t foundCnt=0;
+ for (int idx=0; idx < *size - pLen; idx++){
+ if (memcmp(BitStream+idx, preamble, pLen) == 0){
+ //first index found
+ foundCnt++;
+ if (foundCnt == 1){
+ *startIdx = idx;
+ }
+ if (foundCnt == 2){
+ *size = idx - *startIdx;
+ return 1;
}
- //skip last 5 bit parity test for simplicity.
- return lo;
- }else{
- idx++;
}
}
return 0;
}
//by marshmellow
-//takes 2 arguments - clock and invert both as integers
-//attempts to demodulate ask while decoding manchester
-//prints binary found and saves in graphbuffer for further commands
-int askmandemod(uint8_t *BinStream, size_t *size, int *clk, int *invert)
-{
- int i;
- int high = 0, low = 128;
- *clk=DetectASKClock(BinStream, *size, *clk); //clock default
-
- if (*clk<8) *clk =64;
- if (*clk<32) *clk=32;
- if (*invert != 0 && *invert != 1) *invert=0;
- uint32_t initLoopMax = 200;
- if (initLoopMax > *size) initLoopMax=*size;
- // Detect high and lows
- for (i = 0; i < initLoopMax; ++i) //200 samples should be enough to find high and low values
- {
- if (BinStream[i] > high)
- high = BinStream[i];
- else if (BinStream[i] < low)
- low = BinStream[i];
- }
- if ((high < 158) ){ //throw away static
- //PrintAndLog("no data found");
- return -2;
- }
- //25% fuzz in case highs and lows aren't clipped [marshmellow]
- high=(int)(((high-128)*.75)+128);
- low= (int)(((low-128)*.75)+128);
-
- //PrintAndLog("DEBUG - valid high: %d - valid low: %d",high,low);
- int lastBit = 0; //set first clock check
- uint32_t bitnum = 0; //output counter
- int tol = 0; //clock tolerance adjust - waves will be accepted as within the clock if they fall + or - this value + clock from last valid wave
- if (*clk==32)tol=1; //clock tolerance may not be needed anymore currently set to + or - 1 but could be increased for poor waves or removed entirely
- int iii = 0;
- uint32_t gLen = *size;
- if (gLen > 3000) gLen=3000;
- uint8_t errCnt =0;
- uint32_t bestStart = *size;
- uint32_t bestErrCnt = (*size/1000);
- uint32_t maxErr = (*size/1000);
- //PrintAndLog("DEBUG - lastbit - %d",lastBit);
- //loop to find first wave that works
- for (iii=0; iii < gLen; ++iii){
- if ((BinStream[iii] >= high) || (BinStream[iii] <= low)){
- lastBit=iii-*clk;
- errCnt=0;
- //loop through to see if this start location works
- for (i = iii; i < *size; ++i) {
- if ((BinStream[i] >= high) && ((i-lastBit) > (*clk-tol))){
- lastBit+=*clk;
- } else if ((BinStream[i] <= low) && ((i-lastBit) > (*clk-tol))){
- //low found and we are expecting a bar
- lastBit+=*clk;
- } else {
- //mid value found or no bar supposed to be here
- if ((i-lastBit)>(*clk+tol)){
- //should have hit a high or low based on clock!!
+//takes 1s and 0s and searches for EM410x format - output EM ID
+uint8_t Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx, uint32_t *hi, uint64_t *lo)
+{
+ //no arguments needed - built this way in case we want this to be a direct call from "data " cmds in the future
+ // otherwise could be a void with no arguments
+ //set defaults
+ uint32_t i = 0;
+ if (BitStream[1]>1) return 0; //allow only 1s and 0s
- //debug
- //PrintAndLog("DEBUG - no wave in expected area - location: %d, expected: %d-%d, lastBit: %d - resetting search",i,(lastBit+(clk-((int)(tol)))),(lastBit+(clk+((int)(tol)))),lastBit);
+ // 111111111 bit pattern represent start of frame
+ // include 0 in front to help get start pos
+ uint8_t preamble[] = {0,1,1,1,1,1,1,1,1,1};
+ uint32_t idx = 0;
+ uint32_t parityBits = 0;
+ uint8_t errChk = 0;
+ uint8_t FmtLen = 10;
+ *startIdx = 0;
+ errChk = preambleSearch(BitStream, preamble, sizeof(preamble), size, startIdx);
+ if (errChk == 0 || *size < 64) return 0;
+ if (*size > 64) FmtLen = 22;
+ *startIdx += 1; //get rid of 0 from preamble
+ idx = *startIdx + 9;
+ for (i=0; i<FmtLen; i++){ //loop through 10 or 22 sets of 5 bits (50-10p = 40 bits or 88 bits)
+ parityBits = bytebits_to_byte(BitStream+(i*5)+idx,5);
+ //check even parity - quit if failed
+ if (parityTest(parityBits, 5, 0) == 0) return 0;
+ //set uint64 with ID from BitStream
+ for (uint8_t ii=0; ii<4; ii++){
+ *hi = (*hi << 1) | (*lo >> 63);
+ *lo = (*lo << 1) | (BitStream[(i*5)+ii+idx]);
+ }
+ }
+ if (errChk != 0) return 1;
+ //skip last 5 bit parity test for simplicity.
+ // *size = 64 | 128;
+ return 0;
+}
+//by marshmellow
+//demodulates strong heavily clipped samples
+int cleanAskRawDemod(uint8_t *BinStream, size_t *size, int clk, int invert, int high, int low)
+{
+ size_t bitCnt=0, smplCnt=0, errCnt=0;
+ uint8_t waveHigh = 0;
+ for (size_t i=0; i < *size; i++){
+ if (BinStream[i] >= high && waveHigh){
+ smplCnt++;
+ } else if (BinStream[i] <= low && !waveHigh){
+ smplCnt++;
+ } else { //transition
+ if ((BinStream[i] >= high && !waveHigh) || (BinStream[i] <= low && waveHigh)){
+ if (smplCnt > clk-(clk/4)-1) { //full clock
+ if (smplCnt > clk + (clk/4)+1) { //too many samples
errCnt++;
- lastBit+=*clk;//skip over until hit too many errors
- if (errCnt>(maxErr)) break; //allow 1 error for every 1000 samples else start over
+ BinStream[bitCnt++]=7;
+ } else if (waveHigh) {
+ BinStream[bitCnt++] = invert;
+ BinStream[bitCnt++] = invert;
+ } else if (!waveHigh) {
+ BinStream[bitCnt++] = invert ^ 1;
+ BinStream[bitCnt++] = invert ^ 1;
}
+ waveHigh ^= 1;
+ smplCnt = 0;
+ } else if (smplCnt > (clk/2) - (clk/4)-1) {
+ if (waveHigh) {
+ BinStream[bitCnt++] = invert;
+ } else if (!waveHigh) {
+ BinStream[bitCnt++] = invert ^ 1;
+ }
+ waveHigh ^= 1;
+ smplCnt = 0;
+ } else if (!bitCnt) {
+ //first bit
+ waveHigh = (BinStream[i] >= high);
+ smplCnt = 1;
+ } else {
+ smplCnt++;
+ //transition bit oops
}
- if ((i-iii) >(400 * *clk)) break; //got plenty of bits
- }
- //we got more than 64 good bits and not all errors
- if ((((i-iii)/ *clk) > (64+errCnt)) && (errCnt<maxErr)) {
- //possible good read
- if (errCnt==0){
- bestStart=iii;
- bestErrCnt=errCnt;
- break; //great read - finish
- }
- if (errCnt<bestErrCnt){ //set this as new best run
- bestErrCnt=errCnt;
- bestStart = iii;
- }
+ } else { //haven't hit new high or new low yet
+ smplCnt++;
}
}
}
- if (bestErrCnt<maxErr){
- //best run is good enough set to best run and set overwrite BinStream
- iii=bestStart;
- lastBit = bestStart - *clk;
- bitnum=0;
- for (i = iii; i < *size; ++i) {
- if ((BinStream[i] >= high) && ((i-lastBit) > (*clk-tol))){
- lastBit += *clk;
- BinStream[bitnum] = *invert;
- bitnum++;
- } else if ((BinStream[i] <= low) && ((i-lastBit) > (*clk-tol))){
- //low found and we are expecting a bar
- lastBit+=*clk;
- BinStream[bitnum] = 1-*invert;
- bitnum++;
- } else {
- //mid value found or no bar supposed to be here
- if ((i-lastBit)>(*clk+tol)){
- //should have hit a high or low based on clock!!
-
- //debug
- //PrintAndLog("DEBUG - no wave in expected area - location: %d, expected: %d-%d, lastBit: %d - resetting search",i,(lastBit+(clk-((int)(tol)))),(lastBit+(clk+((int)(tol)))),lastBit);
- if (bitnum > 0){
- BinStream[bitnum]=77;
- bitnum++;
- }
+ *size = bitCnt;
+ return errCnt;
+}
- lastBit+=*clk;//skip over error
- }
+//by marshmellow
+void askAmp(uint8_t *BitStream, size_t size)
+{
+ for(size_t i = 1; i<size; i++){
+ if (BitStream[i]-BitStream[i-1]>=30) //large jump up
+ BitStream[i]=127;
+ else if(BitStream[i]-BitStream[i-1]<=-20) //large jump down
+ BitStream[i]=-127;
+ }
+ return;
+}
+
+//by marshmellow
+//attempts to demodulate ask modulations, askType == 0 for ask/raw, askType==1 for ask/manchester
+int askdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr, uint8_t amp, uint8_t askType)
+{
+ if (*size==0) return -1;
+ int start = DetectASKClock(BinStream, *size, clk, maxErr); //clock default
+ if (*clk==0 || start < 0) return -3;
+ if (*invert != 1) *invert = 0;
+ if (amp==1) askAmp(BinStream, *size);
+ if (g_debugMode==2) prnt("DEBUG: clk %d, beststart %d", *clk, start);
+
+ uint8_t initLoopMax = 255;
+ if (initLoopMax > *size) initLoopMax = *size;
+ // Detect high and lows
+ //25% clip in case highs and lows aren't clipped [marshmellow]
+ int high, low;
+ if (getHiLo(BinStream, initLoopMax, &high, &low, 75, 75) < 1)
+ return -2; //just noise
+
+ size_t errCnt = 0;
+ // if clean clipped waves detected run alternate demod
+ if (DetectCleanAskWave(BinStream, *size, high, low)) {
+ if (g_debugMode==2) prnt("DEBUG: Clean Wave Detected");
+ errCnt = cleanAskRawDemod(BinStream, size, *clk, *invert, high, low);
+ if (askType) //askman
+ return manrawdecode(BinStream, size, 0);
+ else //askraw
+ return errCnt;
+ }
+
+ int lastBit; //set first clock check - can go negative
+ size_t i, bitnum = 0; //output counter
+ uint8_t midBit = 0;
+ uint8_t tol = 0; //clock tolerance adjust - waves will be accepted as within the clock if they fall + or - this value + clock from last valid wave
+ if (*clk <= 32) tol = 1; //clock tolerance may not be needed anymore currently set to + or - 1 but could be increased for poor waves or removed entirely
+ size_t MaxBits = 3072;
+ lastBit = start - *clk;
+
+ for (i = start; i < *size; ++i) {
+ if (i-lastBit >= *clk-tol){
+ if (BinStream[i] >= high) {
+ BinStream[bitnum++] = *invert;
+ } else if (BinStream[i] <= low) {
+ BinStream[bitnum++] = *invert ^ 1;
+ } else if (i-lastBit >= *clk+tol) {
+ if (bitnum > 0) {
+ BinStream[bitnum++]=7;
+ errCnt++;
+ }
+ } else { //in tolerance - looking for peak
+ continue;
}
- if (bitnum >=400) break;
+ midBit = 0;
+ lastBit += *clk;
+ } else if (i-lastBit >= (*clk/2-tol) && !midBit && !askType){
+ if (BinStream[i] >= high) {
+ BinStream[bitnum++] = *invert;
+ } else if (BinStream[i] <= low) {
+ BinStream[bitnum++] = *invert ^ 1;
+ } else if (i-lastBit >= *clk/2+tol) {
+ BinStream[bitnum] = BinStream[bitnum-1];
+ bitnum++;
+ } else { //in tolerance - looking for peak
+ continue;
+ }
+ midBit = 1;
}
- *size=bitnum;
- } else{
- *invert=bestStart;
- *clk=iii;
- return -1;
+ if (bitnum >= MaxBits) break;
}
- return bestErrCnt;
+ *size = bitnum;
+ return errCnt;
}
//by marshmellow
//take 10 and 01 and manchester decode
//run through 2 times and take least errCnt
-int manrawdecode(uint8_t * BitStream, size_t *size)
-{
- int bitnum=0;
- int errCnt =0;
- int i=1;
- int bestErr = 1000;
- int bestRun = 0;
- int ii=1;
- for (ii=1;ii<3;++ii){
- i=1;
- for (i=i+ii;i<*size-2;i+=2){
- if(BitStream[i]==1 && (BitStream[i+1]==0)){
- } else if((BitStream[i]==0)&& BitStream[i+1]==1){
- } else {
+int manrawdecode(uint8_t * BitStream, size_t *size, uint8_t invert)
+{
+ uint16_t bitnum=0, MaxBits = 512, errCnt = 0;
+ size_t i, ii;
+ uint16_t bestErr = 1000, bestRun = 0;
+ if (*size < 16) return -1;
+ //find correct start position [alignment]
+ for (ii=0;ii<2;++ii){
+ for (i=ii; i<*size-3; i+=2)
+ if (BitStream[i]==BitStream[i+1])
errCnt++;
- }
- if(bitnum>300) break;
- }
+
if (bestErr>errCnt){
bestErr=errCnt;
bestRun=ii;
}
errCnt=0;
}
- errCnt=bestErr;
- if (errCnt<20){
- ii=bestRun;
- i=1;
- for (i=i+ii;i < *size-2;i+=2){
- if(BitStream[i] == 1 && (BitStream[i+1] == 0)){
- BitStream[bitnum++]=0;
- } else if((BitStream[i] == 0) && BitStream[i+1] == 1){
- BitStream[bitnum++]=1;
- } else {
- BitStream[bitnum++]=77;
- //errCnt++;
- }
- if(bitnum>300) break;
+ //decode
+ for (i=bestRun; i < *size-3; i+=2){
+ if(BitStream[i] == 1 && (BitStream[i+1] == 0)){
+ BitStream[bitnum++]=invert;
+ } else if((BitStream[i] == 0) && BitStream[i+1] == 1){
+ BitStream[bitnum++]=invert^1;
+ } else {
+ BitStream[bitnum++]=7;
}
- *size=bitnum;
+ if(bitnum>MaxBits) break;
}
- return errCnt;
+ *size=bitnum;
+ 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)
+{
+ size_t modIdx=20000, i=0;
+ if (size>modIdx) return -1;
+ for (size_t idx=0; idx < size; idx++){
+ BitStream[idx+modIdx++] = BitStream[idx];
+ BitStream[idx+modIdx++] = BitStream[idx]^1;
+ }
+ for (; i<(size*2); i++){
+ BitStream[i] = BitStream[i+20000];
+ }
+ return i;
+}
//by marshmellow
-//take 01 or 10 = 0 and 11 or 00 = 1
-int BiphaseRawDecode(uint8_t *BitStream, size_t *size, int offset)
-{
- uint8_t bitnum=0;
- uint32_t errCnt =0;
- uint32_t i=1;
- i=offset;
- for (;i<*size-2;i+=2){
+//take 01 or 10 = 1 and 11 or 00 = 0
+//check for phase errors - should never have 111 or 000 should be 01001011 or 10110100 for 1010
+//decodes biphase or if inverted it is AKA conditional dephase encoding AKA differential manchester encoding
+int BiphaseRawDecode(uint8_t *BitStream, size_t *size, int offset, int invert)
+{
+ uint16_t bitnum = 0;
+ uint16_t errCnt = 0;
+ size_t i = offset;
+ uint16_t MaxBits=512;
+ //if not enough samples - error
+ if (*size < 51) return -1;
+ //check for phase change faults - skip one sample if faulty
+ uint8_t offsetA = 1, offsetB = 1;
+ for (; i<48; i+=2){
+ if (BitStream[i+1]==BitStream[i+2]) offsetA=0;
+ if (BitStream[i+2]==BitStream[i+3]) offsetB=0;
+ }
+ if (!offsetA && offsetB) offset++;
+ for (i=offset; i<*size-3; i+=2){
+ //check for phase error
+ if (BitStream[i+1]==BitStream[i+2]) {
+ BitStream[bitnum++]=7;
+ errCnt++;
+ }
if((BitStream[i]==1 && BitStream[i+1]==0) || (BitStream[i]==0 && BitStream[i+1]==1)){
- BitStream[bitnum++]=1;
+ BitStream[bitnum++]=1^invert;
} else if((BitStream[i]==0 && BitStream[i+1]==0) || (BitStream[i]==1 && BitStream[i+1]==1)){
- BitStream[bitnum++]=0;
+ BitStream[bitnum++]=invert;
} else {
- BitStream[bitnum++]=77;
+ BitStream[bitnum++]=7;
errCnt++;
}
- if(bitnum>250) break;
+ if(bitnum>MaxBits) break;
}
*size=bitnum;
return errCnt;
}
-//by marshmellow
-//takes 2 arguments - clock and invert both as integers
-//attempts to demodulate ask only
-//prints binary found and saves in graphbuffer for further commands
-int askrawdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert)
-{
- uint32_t i;
- // int invert=0; //invert default
- int high = 0, low = 128;
- *clk=DetectASKClock(BinStream, *size, *clk); //clock default
- uint8_t BitStream[502] = {0};
-
- if (*clk<8) *clk =64;
- if (*clk<32) *clk=32;
- if (*invert != 0 && *invert != 1) *invert =0;
- uint32_t initLoopMax = 200;
- if (initLoopMax > *size) initLoopMax=*size;
- // Detect high and lows
- for (i = 0; i < initLoopMax; ++i) //200 samples should be plenty to find high and low values
- {
- if (BinStream[i] > high)
- high = BinStream[i];
- else if (BinStream[i] < low)
- low = BinStream[i];
- }
- if ((high < 158)){ //throw away static
- // PrintAndLog("no data found");
- return -2;
- }
- //25% fuzz in case highs and lows aren't clipped [marshmellow]
- high=(int)(((high-128)*.75)+128);
- low= (int)(((low-128)*.75)+128);
-
- //PrintAndLog("DEBUG - valid high: %d - valid low: %d",high,low);
- int lastBit = 0; //set first clock check
- uint32_t bitnum = 0; //output counter
- uint8_t tol = 0; //clock tolerance adjust - waves will be accepted as within the clock
- // if they fall + or - this value + clock from last valid wave
- if (*clk == 32) tol=1; //clock tolerance may not be needed anymore currently set to
- // + or - 1 but could be increased for poor waves or removed entirely
- uint32_t iii = 0;
- uint32_t gLen = *size;
- if (gLen > 500) gLen=500;
- uint8_t errCnt =0;
- uint32_t bestStart = *size;
- uint32_t bestErrCnt = (*size/1000);
- uint8_t midBit=0;
- //PrintAndLog("DEBUG - lastbit - %d",lastBit);
- //loop to find first wave that works
- for (iii=0; iii < gLen; ++iii){
- if ((BinStream[iii]>=high) || (BinStream[iii]<=low)){
- lastBit=iii-*clk;
- //loop through to see if this start location works
- for (i = iii; i < *size; ++i) {
- if ((BinStream[i] >= high) && ((i-lastBit)>(*clk-tol))){
- lastBit+=*clk;
- BitStream[bitnum] = *invert;
- bitnum++;
- midBit=0;
- } else if ((BinStream[i] <= low) && ((i-lastBit)>(*clk-tol))){
- //low found and we are expecting a bar
- lastBit+=*clk;
- BitStream[bitnum] = 1- *invert;
- bitnum++;
- midBit=0;
- } else if ((BinStream[i]<=low) && (midBit==0) && ((i-lastBit)>((*clk/2)-tol))){
- //mid bar?
- midBit=1;
- BitStream[bitnum]= 1- *invert;
- bitnum++;
- } else if ((BinStream[i]>=high) && (midBit==0) && ((i-lastBit)>((*clk/2)-tol))){
- //mid bar?
- midBit=1;
- BitStream[bitnum]= *invert;
- bitnum++;
- } else if ((i-lastBit)>((*clk/2)+tol) && (midBit==0)){
- //no mid bar found
- midBit=1;
- BitStream[bitnum]= BitStream[bitnum-1];
- bitnum++;
- } else {
- //mid value found or no bar supposed to be here
-
- if ((i-lastBit)>(*clk+tol)){
- //should have hit a high or low based on clock!!
- //debug
- //PrintAndLog("DEBUG - no wave in expected area - location: %d, expected: %d-%d, lastBit: %d - resetting search",i,(lastBit+(clk-((int)(tol)))),(lastBit+(clk+((int)(tol)))),lastBit);
- if (bitnum > 0){
- BitStream[bitnum]=77;
- bitnum++;
- }
+// by marshmellow
+// demod gProxIIDemod
+// error returns as -x
+// success returns start position in BitStream
+// BitStream must contain previously askrawdemod and biphasedemoded data
+int gProxII_Demod(uint8_t BitStream[], size_t *size)
+{
+ size_t startIdx=0;
+ uint8_t preamble[] = {1,1,1,1,1,0};
- errCnt++;
- lastBit+=*clk;//skip over until hit too many errors
- if (errCnt > ((*size/1000))){ //allow 1 error for every 1000 samples else start over
- errCnt=0;
- bitnum=0;//start over
- break;
- }
- }
- }
- if (bitnum>500) break;
- }
- //we got more than 64 good bits and not all errors
- if ((bitnum > (64+errCnt)) && (errCnt<(*size/1000))) {
- //possible good read
- if (errCnt==0) break; //great read - finish
- if (bestStart == iii) break; //if current run == bestErrCnt run (after exhausted testing) then finish
- if (errCnt<bestErrCnt){ //set this as new best run
- bestErrCnt=errCnt;
- bestStart = iii;
- }
- }
- }
- if (iii>=gLen){ //exhausted test
- //if there was a ok test go back to that one and re-run the best run (then dump after that run)
- if (bestErrCnt < (*size/1000)) iii=bestStart;
- }
+ uint8_t errChk = preambleSearch(BitStream, preamble, sizeof(preamble), size, &startIdx);
+ if (errChk == 0) return -3; //preamble not found
+ if (*size != 96) return -2; //should have found 96 bits
+ //check first 6 spacer bits to verify format
+ if (!BitStream[startIdx+5] && !BitStream[startIdx+10] && !BitStream[startIdx+15] && !BitStream[startIdx+20] && !BitStream[startIdx+25] && !BitStream[startIdx+30]){
+ //confirmed proper separator bits found
+ //return start position
+ return (int) startIdx;
}
- if (bitnum>16){
- for (i=0; i < bitnum; ++i){
- BinStream[i]=BitStream[i];
- }
- *size=bitnum;
- } else return -1;
- return errCnt;
+ return -5;
}
+
//translate wave to 11111100000 (1 for each short wave 0 for each long wave)
size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow)
{
- uint32_t last_transition = 0;
- uint32_t idx = 1;
- uint32_t maxVal=0;
+ size_t last_transition = 0;
+ size_t idx = 1;
+ //uint32_t maxVal=0;
if (fchigh==0) fchigh=10;
if (fclow==0) fclow=8;
- // we do care about the actual theshold value as sometimes near the center of the
- // wave we may get static that changes direction of wave for one value
- // if our value is too low it might affect the read. and if our tag or
- // antenna is weak a setting too high might not see anything. [marshmellow]
- if (size<100) return 0;
- for(idx=1; idx<100; idx++){
- if(maxVal<dest[idx]) maxVal = dest[idx];
- }
- // set close to the top of the wave threshold with 25% margin for error
- // less likely to get a false transition up there.
- // (but have to be careful not to go too high and miss some short waves)
- uint8_t threshold_value = (uint8_t)(((maxVal-128)*.75)+128);
-
+ //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
-
- 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
+ // or 10 (fc/10) cycles but in practice due to noise etc we may end up 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;
// 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
- } else if ((idx-last_transition) < (fchigh-1)) { //6-8 = 8 waves
- dest[numBits]=1;
- } else { //9+ = 10 waves
- dest[numBits]=0;
+ } 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;
+
+ } else if (currSample > (fchigh) && !numBits) { //12 + and first bit = garbage
+ //do nothing with beginning garbage
+ } 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;
- numBits++;
}
}
return numBits; //Actually, it returns the number of bytes, but each byte represents a bit: 1 or 0
}
-uint32_t myround2(float f)
-{
- if (f >= 2000) return 2000;//something bad happened
- return (uint32_t) (f + (float)0.5);
-}
-
//translate 11111100000 to 10
-size_t aggregate_bits(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t maxConsequtiveBits,
- uint8_t invert, uint8_t fchigh, uint8_t fclow)
+size_t aggregate_bits(uint8_t *dest, size_t size, uint8_t rfLen,
+ uint8_t invert, uint8_t fchigh, uint8_t fclow)
{
uint8_t lastval=dest[0];
- uint32_t idx=0;
+ size_t idx=0;
size_t numBits=0;
uint32_t n=1;
-
for( idx=1; idx < size; idx++) {
-
- if (dest[idx]==lastval) {
- n++;
- continue;
- }
+ n++;
+ if (dest[idx]==lastval) continue;
+
//if lastval was 1, we have a 1->0 crossing
- if ( dest[idx-1]==1 ) {
- n=myround2((float)(n+1)/((float)(rfLen)/(float)fclow));
- } else {// 0->1 crossing
- n=myround2((float)(n+1)/((float)(rfLen-2)/(float)fchigh)); //-2 for fudge factor
+ if (dest[idx-1]==1) {
+ n = (n * fclow + rfLen/2) / rfLen;
+ } else {// 0->1 crossing
+ n = (n * fchigh + rfLen/2) / rfLen;
}
if (n == 0) n = 1;
- if(n < maxConsequtiveBits) //Consecutive
- {
- if(invert==0){ //invert bits
- memset(dest+numBits, dest[idx-1] , n);
- }else{
- memset(dest+numBits, dest[idx-1]^1 , n);
- }
- numBits += n;
- }
+ memset(dest+numBits, dest[idx-1]^invert , n);
+ numBits += n;
n=0;
lastval=dest[idx];
}//end for
+ // if valid extra bits at the end were all the same frequency - add them in
+ if (n > rfLen/fchigh) {
+ if (dest[idx-2]==1) {
+ n = (n * fclow + rfLen/2) / rfLen;
+ } else {
+ n = (n * fchigh + rfLen/2) / rfLen;
+ }
+ memset(dest+numBits, dest[idx-1]^invert , n);
+ numBits += n;
+ }
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)
{
// FSK demodulator
size = fsk_wave_demod(dest, size, fchigh, fclow);
- size = aggregate_bits(dest, size, rfLen, 192, invert, fchigh, fclow);
+ size = aggregate_bits(dest, size, rfLen, invert, fchigh, fclow);
return size;
}
+
// loop to get raw HID waveform then FSK demodulate the TAG ID from it
-int HIDdemodFSK(uint8_t *dest, size_t size, uint32_t *hi2, uint32_t *hi, uint32_t *lo)
+int HIDdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo)
{
+ if (justNoise(dest, *size)) return -1;
- size_t idx=0; //, found=0; //size=0,
+ size_t numStart=0, size2=*size, startIdx=0;
// FSK demodulator
- size = fskdemod(dest, size,50,0,10,8);
-
- // 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
- uint8_t frame_marker_mask[] = {1,1,1,0,0,0};
- int numshifts = 0;
- idx = 0;
- //one scan
- while( idx + sizeof(frame_marker_mask) < size) {
- // search for a start of frame marker
- if ( memcmp(dest+idx, frame_marker_mask, sizeof(frame_marker_mask)) == 0)
- { // frame marker found
- idx+=sizeof(frame_marker_mask);
- while(dest[idx] != dest[idx+1] && idx < size-2)
- {
- // Keep going until next frame marker (or error)
- // Shift in a bit. Start by shifting high registers
- *hi2 = (*hi2<<1)|(*hi>>31);
- *hi = (*hi<<1)|(*lo>>31);
- //Then, shift in a 0 or one into low
- if (dest[idx] && !dest[idx+1]) // 1 0
- *lo=(*lo<<1)|0;
- else // 0 1
- *lo=(*lo<<1)|1;
- numshifts++;
- idx += 2;
- }
- // Hopefully, we read a tag and hit upon the next frame marker
- if(idx + sizeof(frame_marker_mask) < size)
- {
- if ( memcmp(dest+idx, frame_marker_mask, sizeof(frame_marker_mask)) == 0)
- {
- //good return
- return idx;
- }
- }
- // reset
- *hi2 = *hi = *lo = 0;
- numshifts = 0;
- }else {
- idx++;
+ *size = fskdemod(dest, size2,50,1,10,8); //fsk2a
+ if (*size < 96*2) return -2;
+ // 00011101 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1
+ uint8_t preamble[] = {0,0,0,1,1,1,0,1};
+ // find bitstring in array
+ uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
+ if (errChk == 0) return -3; //preamble not found
+
+ numStart = startIdx + sizeof(preamble);
+ // final loop, go over previously decoded FSK data and manchester decode into usable tag ID
+ for (size_t idx = numStart; (idx-numStart) < *size - sizeof(preamble); idx+=2){
+ if (dest[idx] == dest[idx+1]){
+ return -4; //not manchester data
}
+ *hi2 = (*hi2<<1)|(*hi>>31);
+ *hi = (*hi<<1)|(*lo>>31);
+ //Then, shift in a 0 or one into low
+ if (dest[idx] && !dest[idx+1]) // 1 0
+ *lo=(*lo<<1)|1;
+ else // 0 1
+ *lo=(*lo<<1)|0;
}
- return -1;
+ return (int)startIdx;
}
-uint32_t bytebits_to_byte(uint8_t* src, size_t numbits)
+// loop to get raw paradox waveform then FSK demodulate the TAG ID from it
+int ParadoxdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo)
{
- uint32_t num = 0;
- for(int i = 0 ; i < numbits ; i++)
- {
- num = (num << 1) | (*src);
- src++;
+ if (justNoise(dest, *size)) return -1;
+
+ size_t numStart=0, size2=*size, startIdx=0;
+ // FSK demodulator
+ *size = fskdemod(dest, size2,50,1,10,8); //fsk2a
+ if (*size < 96) return -2;
+
+ // 00001111 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1
+ uint8_t preamble[] = {0,0,0,0,1,1,1,1};
+
+ uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
+ if (errChk == 0) return -3; //preamble not found
+
+ numStart = startIdx + sizeof(preamble);
+ // final loop, go over previously decoded FSK data and manchester decode into usable tag ID
+ for (size_t idx = numStart; (idx-numStart) < *size - sizeof(preamble); idx+=2){
+ if (dest[idx] == dest[idx+1])
+ return -4; //not manchester data
+ *hi2 = (*hi2<<1)|(*hi>>31);
+ *hi = (*hi<<1)|(*lo>>31);
+ //Then, shift in a 0 or one into low
+ if (dest[idx] && !dest[idx+1]) // 1 0
+ *lo=(*lo<<1)|1;
+ else // 0 1
+ *lo=(*lo<<1)|0;
}
- return num;
+ return (int)startIdx;
}
int IOdemodFSK(uint8_t *dest, size_t size)
{
- static const uint8_t THRESHOLD = 140;
- uint32_t idx=0;
+ if (justNoise(dest, size)) return -1;
//make sure buffer has data
- if (size < 66) return -1;
- //test samples are not just noise
- uint8_t justNoise = 1;
- for(idx=0;idx< size && justNoise ;idx++){
- justNoise = dest[idx] < THRESHOLD;
- }
- if(justNoise) return 0;
-
+ if (size < 66*64) return -2;
// FSK demodulator
- size = fskdemod(dest, size, 64, 1, 10, 8); // RF/64 and invert
- if (size < 65) return -1; //did we get a good demod?
+ size = fskdemod(dest, size, 64, 1, 10, 8); // FSK2a RF/64
+ if (size < 65) return -3; //did we get a good demod?
//Index map
//0 10 20 30 40 50 60
//| | | | | | |
//
//XSF(version)facility:codeone+codetwo
//Handle the data
- uint8_t mask[] = {0,0,0,0,0,0,0,0,0,1};
- for( idx=0; idx < (size - 65); idx++) {
- if ( memcmp(dest + idx, mask, sizeof(mask))==0) {
- //frame marker found
- if (!dest[idx+8] && dest[idx+17]==1 && dest[idx+26]==1 && dest[idx+35]==1 && dest[idx+44]==1 && dest[idx+53]==1){
- //confirmed proper separator bits found
- //return start position
- return (int) idx;
- }
- }
+ size_t startIdx = 0;
+ uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,1};
+ uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), &size, &startIdx);
+ if (errChk == 0) return -4; //preamble not found
+
+ if (!dest[startIdx+8] && dest[startIdx+17]==1 && dest[startIdx+26]==1 && dest[startIdx+35]==1 && dest[startIdx+44]==1 && dest[startIdx+53]==1){
+ //confirmed proper separator bits found
+ //return start position
+ 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;
+}
+
+// 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)
+{
+ //make sure buffer has enough data
+ if (*size < 96*50) return -1;
+
+ if (justNoise(dest, *size)) return -2;
+
+ // FSK demodulator
+ *size = fskdemod(dest, *size, 50, 1, 10, 8); // fsk2a RF/50
+ if (*size < 96) return -3; //did we get a good demod?
+
+ uint8_t preamble[] = {0,0,0,0,0,0,0,1};
+ size_t startIdx = 0;
+ uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
+ if (errChk == 0) return -4; //preamble not found
+ if (*size != 96) return -5;
+ return (int)startIdx;
+}
+
+// by marshmellow
+// FSK Demod then try to locate a Farpointe Data (pyramid) ID
+int PyramiddemodFSK(uint8_t *dest, size_t *size)
+{
+ //make sure buffer has data
+ if (*size < 128*50) return -5;
+
+ //test samples are not just noise
+ if (justNoise(dest, *size)) return -1;
+
+ // FSK demodulator
+ *size = fskdemod(dest, *size, 50, 1, 10, 8); // fsk2a RF/50
+ if (*size < 128) return -2; //did we get a good demod?
+
+ uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1};
+ size_t startIdx = 0;
+ uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
+ if (errChk == 0) return -4; //preamble not found
+ if (*size != 128) return -3;
+ return (int)startIdx;
+}
+
+// by marshmellow
+// 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)
+{
+ bool allArePeaks = true;
+ uint16_t cntPeaks=0;
+ size_t loopEnd = 512+160;
+ if (loopEnd > size) loopEnd = size;
+ for (size_t i=160; i<loopEnd; i++){
+ if (dest[i]>low && dest[i]<high)
+ allArePeaks = false;
+ else
+ cntPeaks++;
+ }
+ if (!allArePeaks){
+ if (cntPeaks > 300) return true;
+ }
+ return allArePeaks;
+}
+// by marshmellow
+// to help detect clocks on heavily clipped samples
+// based on count of low to low
+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;
+ 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))
+ ++i;
+ while ((dest[i] > low) && (i < size))
+ ++i;
+
+ // loop through all samples
+ while (i < size) {
+ // measure from low to low
+ while ((dest[i] > low) && (i < size))
+ ++i;
+ startwave= i;
+ while ((dest[i] < high) && (i < size))
+ ++i;
+ while ((dest[i] > low) && (i < size))
+ ++i;
+ //get minimum measured distance
+ if (i-startwave < minClk && i < size)
+ minClk = i - startwave;
+ }
+ // set clock
+ if (g_debugMode==2) prnt("DEBUG ASK: detectstrongASKclk smallest wave: %d",minClk);
+ for (uint8_t clkCnt = 0; clkCnt<7; clkCnt++) {
+ if (minClk >= fndClk[clkCnt]-(fndClk[clkCnt]/8) && minClk <= fndClk[clkCnt]+1)
+ return fndClk[clkCnt];
}
return 0;
}
// by marshmellow
// not perfect especially with lower clocks or VERY good antennas (heavy wave clipping)
// maybe somehow adjust peak trimming value based on samples to fix?
-int DetectASKClock(uint8_t dest[], size_t size, int clock)
+// return start index of best starting position for that clock and return clock (by reference)
+int DetectASKClock(uint8_t dest[], size_t size, int *clock, int maxErr)
{
- int i=0;
- int peak=0;
- int low=128;
- int clk[]={16,32,40,50,64,100,128,256};
- int loopCnt = 256; //don't need to loop through entire array...
- if (size<loopCnt) loopCnt = size;
-
- //if we already have a valid clock quit
- for (;i<8;++i)
- if (clk[i] == clock) return clock;
+ size_t i=1;
+ 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+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 (clk[i] == *clock) clockFnd = i;
+ //clock found but continue to find best startpos
//get high and low peak
- for (i=0; i < loopCnt; ++i){
- if(dest[i] > peak){
- peak = dest[i];
- }
- if(dest[i] < low){
- low = dest[i];
+ int peak, low;
+ if (getHiLo(dest, loopCnt, &peak, &low, 75, 75) < 1) return -1;
+
+ //test for large clean peaks
+ if (!clockFnd){
+ if (DetectCleanAskWave(dest, size, peak, low)==1){
+ int ans = DetectStrongAskClock(dest, size, peak, low);
+ if (g_debugMode==2) prnt("DEBUG ASK: detectaskclk Clean Ask Wave Detected: clk %d",ans);
+ for (i=clkEnd-1; i>0; i--){
+ if (clk[i] == ans) {
+ *clock = ans;
+ //clockFnd = i;
+ return 0; // for strong waves i don't use the 'best start position' yet...
+ //break; //clock found but continue to find best startpos [not yet]
+ }
+ }
}
}
- peak=(int)(((peak-128)*.75)+128);
- low= (int)(((low-128)*.75)+128);
- int ii;
- int clkCnt;
- int tol = 0;
- int bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000};
- int errCnt=0;
+ uint8_t ii;
+ uint8_t clkCnt, tol = 0;
+ uint16_t bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000,1000};
+ uint8_t bestStart[]={0,0,0,0,0,0,0,0,0};
+ size_t errCnt = 0;
+ size_t arrLoc, loopEnd;
+
+ if (clockFnd>0) {
+ clkCnt = clockFnd;
+ clkEnd = clockFnd+1;
+ }
+ else clkCnt=1;
+
//test each valid clock from smallest to greatest to see which lines up
- for(clkCnt=0; clkCnt < 6; ++clkCnt){
- if (clk[clkCnt] == 32){
+ for(; clkCnt < clkEnd; clkCnt++){
+ if (clk[clkCnt] <= 32){
tol=1;
}else{
tol=0;
}
+ //if no errors allowed - keep start within the first clock
+ if (!maxErr && size > clk[clkCnt]*2 + tol && clk[clkCnt]<128) loopCnt=clk[clkCnt]*2;
bestErr[clkCnt]=1000;
- //try lining up the peaks by moving starting point (try first 256)
- for (ii=0; ii< loopCnt; ++ii){
- if ((dest[ii] >= peak) || (dest[ii] <= low)){
- errCnt=0;
- // now that we have the first one lined up test rest of wave array
- for (i=0; i<((int)(size/clk[clkCnt])-1); ++i){
- if (dest[ii+(i*clk[clkCnt])]>=peak || dest[ii+(i*clk[clkCnt])]<=low){
- }else if(dest[ii+(i*clk[clkCnt])-tol]>=peak || dest[ii+(i*clk[clkCnt])-tol]<=low){
- }else if(dest[ii+(i*clk[clkCnt])+tol]>=peak || dest[ii+(i*clk[clkCnt])+tol]<=low){
- }else{ //error no peak detected
- errCnt++;
- }
+ //try lining up the peaks by moving starting point (try first few clocks)
+ for (ii=0; ii < loopCnt; ii++){
+ if (dest[ii] < peak && dest[ii] > low) continue;
+
+ errCnt=0;
+ // now that we have the first one lined up test rest of wave array
+ loopEnd = ((size-ii-tol) / clk[clkCnt]) - 1;
+ for (i=0; i < loopEnd; ++i){
+ arrLoc = ii + (i * clk[clkCnt]);
+ if (dest[arrLoc] >= peak || dest[arrLoc] <= low){
+ }else if (dest[arrLoc-tol] >= peak || dest[arrLoc-tol] <= low){
+ }else if (dest[arrLoc+tol] >= peak || dest[arrLoc+tol] <= low){
+ }else{ //error no peak detected
+ errCnt++;
}
- //if we found no errors this is correct one - return this clock
- if(errCnt==0) return clk[clkCnt];
- //if we found errors see if it is lowest so far and save it as best run
- if(errCnt<bestErr[clkCnt]) bestErr[clkCnt]=errCnt;
+ }
+ //if we found no errors then we can stop here and a low clock (common clocks)
+ // this is correct one - return this clock
+ if (g_debugMode == 2) prnt("DEBUG ASK: clk %d, err %d, startpos %d, endpos %d",clk[clkCnt],errCnt,ii,i);
+ if(errCnt==0 && clkCnt<7) {
+ if (!clockFnd) *clock = clk[clkCnt];
+ return ii;
+ }
+ //if we found errors see if it is lowest so far and save it as best run
+ if(errCnt<bestErr[clkCnt]){
+ bestErr[clkCnt]=errCnt;
+ bestStart[clkCnt]=ii;
}
}
}
- int iii=0;
- int best=0;
- for (iii=0; iii<7;++iii){
- if (bestErr[iii]<bestErr[best]){
- // current best bit to error ratio vs new bit to error ratio
- if (((size/clk[best])/bestErr[best] < (size/clk[iii])/bestErr[iii]) ){
+ uint8_t iii;
+ uint8_t best=0;
+ for (iii=1; iii<clkEnd; ++iii){
+ if (bestErr[iii] < bestErr[best]){
+ if (bestErr[iii] == 0) bestErr[iii]=1;
+ // current best bit to error ratio vs new bit to error ratio
+ if ( (size/clk[best])/bestErr[best] < (size/clk[iii])/bestErr[iii] ){
best = iii;
}
}
+ if (g_debugMode == 2) prnt("DEBUG ASK: clk %d, # Errors %d, Current Best Clk %d, bestStart %d",clk[iii],bestErr[iii],clk[best],bestStart[best]);
}
- return clk[best];
+ if (!clockFnd) *clock = clk[best];
+ return bestStart[best];
}
//by marshmellow
-//detect psk clock by reading #peaks vs no peaks(or errors)
-int DetectpskNRZClock(uint8_t dest[], size_t size, int clock)
+//detect psk clock by reading each phase shift
+// a phase shift is determined by measuring the sample length of each wave
+int DetectPSKClock(uint8_t dest[], size_t size, int clock)
{
- int i=0;
- int peak=0;
- int low=128;
- int clk[]={16,32,40,50,64,100,128,256};
- int loopCnt = 2048; //don't need to loop through entire array...
- if (size<loopCnt) loopCnt = size;
+ 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-20;
//if we already have a valid clock quit
+ size_t i=1;
for (; i < 8; ++i)
if (clk[i] == clock) return clock;
- //get high and low peak
- for (i=0; i < loopCnt; ++i){
- if(dest[i] > peak){
- peak = dest[i];
+ size_t waveStart=0, waveEnd=0, firstFullWave=0, lastClkBit=0;
+ uint8_t clkCnt, fc=0, fullWaveLen=0, tol=1;
+ uint16_t peakcnt=0, errCnt=0, waveLenCnt=0;
+ uint16_t bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000,1000};
+ 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;
+ if (g_debugMode==2) prnt("DEBUG PSK: FC: %d",fc);
+
+ //find first full wave
+ for (i=160; i<loopCnt; i++){
+ if (dest[i] < dest[i+1] && dest[i+1] >= dest[i+2]){
+ if (waveStart == 0) {
+ waveStart = i+1;
+ //prnt("DEBUG: waveStart: %d",waveStart);
+ } else {
+ waveEnd = i+1;
+ //prnt("DEBUG: waveEnd: %d",waveEnd);
+ waveLenCnt = waveEnd-waveStart;
+ if (waveLenCnt > fc){
+ firstFullWave = waveStart;
+ fullWaveLen=waveLenCnt;
+ break;
+ }
+ waveStart=0;
+ }
+ }
+ }
+ if (g_debugMode ==2) prnt("DEBUG PSK: 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--){
+ lastClkBit = firstFullWave; //set end of wave as clock align
+ waveStart = 0;
+ errCnt=0;
+ peakcnt=0;
+ if (g_debugMode == 2) prnt("DEBUG PSK: clk: %d, lastClkBit: %d",clk[clkCnt],lastClkBit);
+
+ for (i = firstFullWave+fullWaveLen-1; i < loopCnt-2; i++){
+ //top edge of wave = start of new wave
+ if (dest[i] < dest[i+1] && dest[i+1] >= dest[i+2]){
+ if (waveStart == 0) {
+ waveStart = i+1;
+ waveLenCnt=0;
+ } else { //waveEnd
+ waveEnd = i+1;
+ waveLenCnt = waveEnd-waveStart;
+ if (waveLenCnt > fc){
+ //if this wave is a phase shift
+ if (g_debugMode == 2) prnt("DEBUG PSK: phase shift at: %d, len: %d, nextClk: %d, i: %d, fc: %d",waveStart,waveLenCnt,lastClkBit+clk[clkCnt]-tol,i+1,fc);
+ if (i+1 >= lastClkBit + clk[clkCnt] - tol){ //should be a clock bit
+ peakcnt++;
+ lastClkBit+=clk[clkCnt];
+ } else if (i<lastClkBit+8){
+ //noise after a phase shift - ignore
+ } else { //phase shift before supposed to based on clock
+ errCnt++;
+ }
+ } else if (i+1 > lastClkBit + clk[clkCnt] + tol + fc){
+ lastClkBit+=clk[clkCnt]; //no phase shift but clock bit
+ }
+ waveStart=i+1;
+ }
+ }
}
- if(dest[i] < low){
- low = dest[i];
+ if (errCnt == 0){
+ return clk[clkCnt];
+ }
+ if (errCnt <= bestErr[clkCnt]) bestErr[clkCnt]=errCnt;
+ if (peakcnt > peaksdet[clkCnt]) peaksdet[clkCnt]=peakcnt;
+ }
+ //all tested with errors
+ //return the highest clk with the most peaks found
+ uint8_t best=7;
+ for (i=7; i>=1; i--){
+ if (peaksdet[i] > peaksdet[best]) {
+ best = i;
+ }
+ if (g_debugMode == 2) prnt("DEBUG PSK: Clk: %d, peaks: %d, errs: %d, bestClk: %d",clk[i],peaksdet[i],bestErr[i],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;
}
}
- peak=(int)(((peak-128)*.90)+128);
- low= (int)(((low-128)*.90)+128);
- //PrintAndLog("DEBUG: peak: %d, low: %d",peak,low);
- int ii;
+ if (lowestTransition == 255) lowestTransition = 0;
+ if (g_debugMode==2) prnt("DEBUG NRZ: detectstrongNRZclk smallest wave: %d",lowestTransition);
+ 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)
+{
+ size_t i=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-20;
+ //if we already have a valid clock quit
+ for (; i < 8; ++i)
+ if (clk[i] == clock) return clock;
+
+ //get high and low peak
+ int peak, low;
+ if (getHiLo(dest, loopCnt, &peak, &low, 75, 75) < 1) return 0;
+
+ int lowestTransition = DetectStrongNRZClk(dest, size-20, peak, low);
+ size_t ii;
uint8_t clkCnt;
uint8_t tol = 0;
- int peakcnt=0;
- int errCnt=0;
- int bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000,1000};
- int peaksdet[]={0,0,0,0,0,0,0,0,0};
- //test each valid clock from smallest to greatest to see which lines up
- for(clkCnt=0; clkCnt < 6; ++clkCnt){
- if (clk[clkCnt] == 32){
- tol=0;
- }else{
- tol=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){
+ if (!firstpeak) continue;
+ smplCnt++;
+ } else {
+ 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;
+ }
}
+ }
+ 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){
+ //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)
- for (ii=0; ii< loopCnt; ++ii){
+ for (ii=20; ii < loopCnt; ++ii){
if ((dest[ii] >= peak) || (dest[ii] <= low)){
- errCnt=0;
- peakcnt=0;
- // now that we have the first one lined up test rest of wave array
- for (i=0; i < ((int)(size/clk[clkCnt])-1); ++i){
- if (dest[ii+(i*clk[clkCnt])]>=peak || dest[ii+(i*clk[clkCnt])]<=low){
- peakcnt++;
- }else if(dest[ii+(i*clk[clkCnt])-tol]>=peak || dest[ii+(i*clk[clkCnt])-tol]<=low){
- peakcnt++;
- }else if(dest[ii+(i*clk[clkCnt])+tol]>=peak || dest[ii+(i*clk[clkCnt])+tol]<=low){
- peakcnt++;
- }else{ //error no peak detected
- errCnt++;
+ 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]) {
peaksdet[clkCnt]=peakcnt;
- bestErr[clkCnt]=errCnt;
}
}
}
}
- int iii=0;
- int best=0;
- //int ratio2; //debug
- int ratio;
- //int bits;
- for (iii=0; iii < 7; ++iii){
- ratio=1000;
- //ratio2=1000; //debug
- //bits=size/clk[iii]; //debug
- if (peaksdet[iii] > 0){
- ratio=bestErr[iii]/peaksdet[iii];
- if (((bestErr[best]/peaksdet[best]) > (ratio)+1)){
+ int iii=7;
+ uint8_t best=0;
+ for (iii=7; iii > 0; iii--){
+ 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;
}
- //ratio2=bits/peaksdet[iii]; //debug
+ } else if (peaksdet[iii] > peaksdet[best]){
+ best = iii;
}
- //PrintAndLog("DEBUG: Clk: %d, peaks: %d, errs: %d, bestClk: %d, ratio: %d, bits: %d, peakbitr: %d",clk[iii],peaksdet[iii],bestErr[iii],clk[best],ratio, bits,ratio2);
+ if (g_debugMode==2) prnt("DEBUG NRZ: Clk: %d, peaks: %d, maxPeak: %d, bestClk: %d, lowestTrs: %d",clk[iii],peaksdet[iii],maxPeak, clk[best], lowestTransition);
}
+
return clk[best];
}
-//by marshmellow (attempt to get rid of high immediately after a low)
-void pskCleanWave(uint8_t *bitStream, size_t size)
-{
- int i;
- int low=128;
- int high=0;
- int gap = 4;
- // int loopMax = 2048;
- int newLow=0;
- int newHigh=0;
- for (i=0; i < size; ++i){
- if (bitStream[i] < low) low=bitStream[i];
- if (bitStream[i] > high) high=bitStream[i];
- }
- high = (int)(((high-128)*.80)+128);
- low = (int)(((low-128)*.90)+128);
- //low = (uint8_t)(((int)(low)-128)*.80)+128;
- for (i=0; i < size; ++i){
- if (newLow == 1){
- bitStream[i]=low+8;
- gap--;
- if (gap == 0){
- newLow=0;
- gap=4;
- }
- }else if (newHigh == 1){
- bitStream[i]=high-8;
- gap--;
- if (gap == 0){
- newHigh=0;
- gap=4;
- }
+// by marshmellow
+// convert psk1 demod to psk2 demod
+// only transition waves are 1s
+void psk1TOpsk2(uint8_t *BitStream, size_t size)
+{
+ size_t i=1;
+ uint8_t lastBit=BitStream[0];
+ for (; i<size; i++){
+ if (BitStream[i]==7){
+ //ignore errors
+ } else if (lastBit!=BitStream[i]){
+ lastBit=BitStream[i];
+ BitStream[i]=1;
+ } else {
+ BitStream[i]=0;
}
- if (bitStream[i] <= low) newLow=1;
- if (bitStream[i] >= high) newHigh=1;
}
return;
}
+// by marshmellow
+// convert psk2 demod to psk1 demod
+// from only transition waves are 1s to phase shifts change bit
+void psk2TOpsk1(uint8_t *BitStream, size_t size)
+{
+ uint8_t phase=0;
+ for (size_t i=0; i<size; i++){
+ if (BitStream[i]==1){
+ phase ^=1;
+ }
+ BitStream[i]=phase;
+ }
+ return;
+}
-//redesigned by marshmellow adjusted from existing decode functions
-//indala id decoding - only tested on 26 bit tags, but attempted to make it work for more
+// redesigned by marshmellow adjusted from existing decode functions
+// indala id decoding - only tested on 26 bit tags, but attempted to make it work for more
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;
- 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;
- }
+ 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;
+
+ return (int) startidx;
+}
+
+// by marshmellow - demodulate NRZ wave
+// peaks invert bit (high=1 low=0) each clock cycle = 1 bit determined by last peak
+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 (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
+
+ 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;
+ }
+ //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 (i == (start + long_wait)) {
+ }
+ *size = numBits;
+ return 0;
+}
+
+//by marshmellow
+//detects the bit clock for FSK given the high and low Field Clocks
+uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fcLow)
+{
+ uint8_t clk[] = {8,16,32,40,50,64,100,128,0};
+ uint16_t rfLens[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
+ uint8_t rfCnts[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
+ uint8_t rfLensFnd = 0;
+ uint8_t lastFCcnt = 0;
+ uint16_t fcCounter = 0;
+ uint16_t rfCounter = 0;
+ uint8_t firstBitFnd = 0;
+ size_t i;
+ if (size == 0) return 0;
+
+ 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);
+ // 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;
+
+ for (; i < size-20; i++){
+ fcCounter++;
+ rfCounter++;
+
+ if (BitStream[i] <= BitStream[i-1] || BitStream[i] < BitStream[i+1])
+ continue;
+ // else new peak
+ // if we got less than the small fc + tolerance then set it to the small fc
+ if (fcCounter < fcLow+fcTol)
+ fcCounter = fcLow;
+ else //set it to the large fc
+ fcCounter = fcHigh;
+
+ //look for bit clock (rf/xx)
+ if ((fcCounter < lastFCcnt || fcCounter > lastFCcnt)){
+ //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-4) && rfLens[ii] <= (rfCounter+4)){
+ rfCnts[ii]++;
+ rfCounter = 0;
+ break;
+ }
+ }
+ if (rfCounter > 0 && rfLensFnd < 15){
+ //PrintAndLog("DEBUG: rfCntr %d, fcCntr %d",rfCounter,fcCounter);
+ rfCnts[rfLensFnd]++;
+ rfLens[rfLensFnd++] = rfCounter;
+ }
+ } else {
+ firstBitFnd++;
+ }
+ rfCounter=0;
+ lastFCcnt=fcCounter;
}
+ fcCounter=0;
}
- if (start == *size - 250 + 1) {
- // did not find start sequence
- return -1;
- }
- //found start once now test length by finding next one
- // Inverting signal if needed
- if (first == 1) {
- for (i = start; i < *size; i++) {
- bitStream[i] = !bitStream[i];
+ uint8_t rfHighest=15, rfHighest2=15, rfHighest3=15;
+
+ for (i=0; i<15; i++){
+ //get highest 2 RF values (might need to get more values to compare or compare all?)
+ if (rfCnts[i]>rfCnts[rfHighest]){
+ rfHighest3=rfHighest2;
+ rfHighest2=rfHighest;
+ rfHighest=i;
+ } else if(rfCnts[i]>rfCnts[rfHighest2]){
+ rfHighest3=rfHighest2;
+ rfHighest2=i;
+ } else if(rfCnts[i]>rfCnts[rfHighest3]){
+ rfHighest3=i;
}
- *invert = 1;
- }else *invert=0;
+ if (g_debugMode==2) prnt("DEBUG FSK: RF %d, cnts %d",rfLens[i], rfCnts[i]);
+ }
+ // set allowed clock remainder tolerance to be 1 large field clock length+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;
+
+ if (g_debugMode==2) prnt("DEBUG FSK: most counted rf values: 1 %d, 2 %d, 3 %d",rfLens[rfHighest],rfLens[rfHighest2],rfLens[rfHighest3]);
- int iii;
- for (ii=start+29; ii <= *size - 250; ii++) {
- first2 = bitStream[ii];
- for (iii = ii; iii < ii + long_wait; iii++) {
- if (bitStream[iii] != first2) {
- break;
+ // 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;
+ 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 (g_debugMode==2) prnt("DEBUG FSK: clk %d divides into the 3 most rf values within tolerance",clk[ii]);
+ break;
+ }
}
}
- if (iii == (ii + long_wait)) {
- break;
- }
- }
- if (ii== *size - 250 + 1){
- // did not find second start sequence
- return -2;
}
- bitCnt=ii-start;
- // Dumping UID
- i = start;
- for (ii = 0; ii < bitCnt; ii++) {
- bitStream[ii] = bitStream[i++];
- }
- *size=bitCnt;
- return 1;
-}
+ if (ii<0) return 0; // oops we went too far
+ return clk[ii];
+}
-//by marshmellow - demodulate PSK wave or NRZ wave (both similar enough)
-//peaks switch bit (high=1 low=0) each clock cycle = 1 bit determined by last peak
-int pskNRZrawDemod(uint8_t *dest, size_t *size, int *clk, int *invert)
+//by marshmellow
+//countFC is to detect the field clock lengths.
+//counts and returns the 2 most common wave lengths
+//mainly used for FSK field clock detection
+uint16_t countFC(uint8_t *BitStream, size_t size, uint8_t fskAdj)
{
- pskCleanWave(dest,*size);
- int clk2 = DetectpskNRZClock(dest, *size, *clk);
- *clk=clk2;
- uint32_t i;
- uint8_t high=0, low=128;
- uint32_t gLen = *size;
- if (gLen > 1280) gLen=1280;
- // get high
- for (i=0; i < gLen; ++i){
- if (dest[i] > high) high = dest[i];
- if (dest[i] < low) low = dest[i];
- }
- //fudge high/low bars by 25%
- high = (uint8_t)((((int)(high)-128)*.75)+128);
- low = (uint8_t)((((int)(low)-128)*.80)+128);
+ 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;
+ size_t i;
+ if (size == 0) return 0;
- //PrintAndLog("DEBUG - valid high: %d - valid low: %d",high,low);
- int lastBit = 0; //set first clock check
- uint32_t bitnum = 0; //output counter
- uint8_t tol = 0; //clock tolerance adjust - waves will be accepted as within the clock if they fall + or - this value + clock from last valid wave
- if (*clk==32)tol=2; //clock tolerance may not be needed anymore currently set to + or - 1 but could be increased for poor waves or removed entirely
- uint32_t iii = 0;
- uint8_t errCnt =0;
- uint32_t bestStart = *size;
- uint32_t maxErr = (*size/1000);
- uint32_t bestErrCnt = maxErr;
- //uint8_t midBit=0;
- uint8_t curBit=0;
- uint8_t bitHigh=0;
- uint8_t ignorewin=*clk/8;
- //PrintAndLog("DEBUG - lastbit - %d",lastBit);
- //loop to find first wave that works - align to clock
- for (iii=0; iii < gLen; ++iii){
- if ((dest[iii]>=high) || (dest[iii]<=low)){
- lastBit=iii-*clk;
- //loop through to see if this start location works
- for (i = iii; i < *size; ++i) {
- //if we found a high bar and we are at a clock bit
- if ((dest[i]>=high ) && (i>=lastBit+*clk-tol && i<=lastBit+*clk+tol)){
- bitHigh=1;
- lastBit+=*clk;
- ignorewin=*clk/8;
- bitnum++;
- //else if low bar found and we are at a clock point
- }else if ((dest[i]<=low ) && (i>=lastBit+*clk-tol && i<=lastBit+*clk+tol)){
- bitHigh=1;
- lastBit+=*clk;
- ignorewin=*clk/8;
- bitnum++;
- //else if no bars found
- }else if(dest[i] < high && dest[i] > low) {
- if (ignorewin==0){
- bitHigh=0;
- }else ignorewin--;
- //if we are past a clock point
- if (i >= lastBit+*clk+tol){ //clock val
- lastBit+=*clk;
- bitnum++;
- }
- //else if bar found but we are not at a clock bit and we did not just have a clock bit
- }else if ((dest[i]>=high || dest[i]<=low) && (i<lastBit+*clk-tol || i>lastBit+*clk+tol) && (bitHigh==0)){
- //error bar found no clock...
- errCnt++;
- }
- if (bitnum>=1000) break;
+ // prime i to first up transition
+ for (i = 160; i < size-20; i++)
+ if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1])
+ break;
+
+ for (; i < size-20; i++){
+ if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1]){
+ // new up transition
+ fcCounter++;
+ if (fskAdj){
+ //if we had 5 and now have 9 then go back to 8 (for when we get a fc 9 instead of an 8)
+ if (lastFCcnt==5 && fcCounter==9) fcCounter--;
+ //if fc=9 or 4 add one (for when we get a fc 9 instead of 10 or a 4 instead of a 5)
+ if ((fcCounter==9) || fcCounter==4) fcCounter++;
+ // save last field clock count (fc/xx)
+ lastFCcnt = fcCounter;
}
- //we got more than 64 good bits and not all errors
- if ((bitnum > (64+errCnt)) && (errCnt < (maxErr))) {
- //possible good read
- if (errCnt == 0){
- bestStart = iii;
- bestErrCnt = errCnt;
- break; //great read - finish
- }
- if (bestStart == iii) break; //if current run == bestErrCnt run (after exhausted testing) then finish
- if (errCnt < bestErrCnt){ //set this as new best run
- bestErrCnt = errCnt;
- bestStart = iii;
+ // find which fcLens to save it to:
+ for (int ii=0; ii<15; ii++){
+ if (fcLens[ii]==fcCounter){
+ fcCnts[ii]++;
+ fcCounter=0;
+ break;
}
}
+ if (fcCounter>0 && fcLensFnd<15){
+ //add new fc length
+ fcCnts[fcLensFnd]++;
+ fcLens[fcLensFnd++]=fcCounter;
+ }
+ fcCounter=0;
+ } else {
+ // count sample
+ fcCounter++;
}
}
- if (bestErrCnt < maxErr){
- //best run is good enough set to best run and set overwrite BinStream
- iii=bestStart;
- lastBit=bestStart-*clk;
- bitnum=0;
- for (i = iii; i < *size; ++i) {
- //if we found a high bar and we are at a clock bit
- if ((dest[i] >= high ) && (i>=lastBit+*clk-tol && i<=lastBit+*clk+tol)){
- bitHigh=1;
- lastBit+=*clk;
- curBit=1-*invert;
- dest[bitnum]=curBit;
- ignorewin=*clk/8;
- bitnum++;
- //else if low bar found and we are at a clock point
- }else if ((dest[i]<=low ) && (i>=lastBit+*clk-tol && i<=lastBit+*clk+tol)){
- bitHigh=1;
- lastBit+=*clk;
- curBit=*invert;
- dest[bitnum]=curBit;
- ignorewin=*clk/8;
- bitnum++;
- //else if no bars found
- }else if(dest[i]<high && dest[i]>low) {
- if (ignorewin==0){
- bitHigh=0;
- }else ignorewin--;
- //if we are past a clock point
- if (i>=lastBit+*clk+tol){ //clock val
- lastBit+=*clk;
- dest[bitnum]=curBit;
- bitnum++;
- }
- //else if bar found but we are not at a clock bit and we did not just have a clock bit
- }else if ((dest[i]>=high || dest[i]<=low) && ((i<lastBit+*clk-tol) || (i>lastBit+*clk+tol)) && (bitHigh==0)){
- //error bar found no clock...
- bitHigh=1;
- dest[bitnum]=77;
- bitnum++;
- errCnt++;
- }
- if (bitnum >=1000) break;
+
+ uint8_t best1=14, best2=14, best3=14;
+ uint16_t maxCnt1=0;
+ // go through fclens and find which ones are bigest 2
+ for (i=0; i<15; i++){
+ // get the 3 best FC values
+ if (fcCnts[i]>maxCnt1) {
+ best3=best2;
+ best2=best1;
+ maxCnt1=fcCnts[i];
+ best1=i;
+ } else if(fcCnts[i]>fcCnts[best2]){
+ best3=best2;
+ best2=i;
+ } else if(fcCnts[i]>fcCnts[best3]){
+ best3=i;
}
- *size=bitnum;
+ if (g_debugMode==2) prnt("DEBUG countfc: FC %u, Cnt %u, best fc: %u, best2 fc: %u",fcLens[i],fcCnts[i],fcLens[best1],fcLens[best2]);
+ }
+ if (fcLens[best1]==0) return 0;
+ uint8_t fcH=0, fcL=0;
+ if (fcLens[best1]>fcLens[best2]){
+ fcH=fcLens[best1];
+ fcL=fcLens[best2];
} else{
- *size=bitnum;
- *clk=bestStart;
- return -1;
+ fcH=fcLens[best2];
+ fcL=fcLens[best1];
+ }
+ if ((size-180)/fcH/3 > fcCnts[best1]+fcCnts[best2]) {
+ if (g_debugMode==2) prnt("DEBUG countfc: fc is too large: %u > %u. Not psk or fsk",(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
- if (bitnum>16){
- *size=bitnum;
- } else return -1;
- return errCnt;
+ uint16_t fcs = (((uint16_t)fcH)<<8) | fcL;
+ if (fskAdj) return fcs;
+ return fcLens[best1];
}
+//by marshmellow - demodulate PSK1 wave
+//uses wave lengths (# Samples)
+int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert)
+{
+ if (size == 0) return -1;
+ 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;
+ uint16_t errCnt=0, waveLenCnt=0;
+ fc = countFC(dest, *size, 0);
+ if (fc!=2 && fc!=4 && fc!=8) return -1;
+ //PrintAndLog("DEBUG: FC: %d",fc);
+ *clock = DetectPSKClock(dest, *size, *clock);
+ if (*clock == 0) return -1;
+ int avgWaveVal=0, lastAvgWaveVal=0;
+ //find first phase shift
+ for (i=0; i<loopCnt; i++){
+ if (dest[i]+fc < dest[i+1] && dest[i+1] >= dest[i+2]){
+ waveEnd = i+1;
+ //PrintAndLog("DEBUG: waveEnd: %d",waveEnd);
+ waveLenCnt = waveEnd-waveStart;
+ 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;
+ //if average wave value is > graph 0 then it is an up wave or a 1
+ if (lastAvgWaveVal > 123) curPhase ^= 1; //fudge graph 0 a little 123 vs 128
+ break;
+ }
+ waveStart = i+1;
+ avgWaveVal = 0;
+ }
+ 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: clk: %d, lastClkBit: %d", *clock, lastClkBit);
+ waveStart = 0;
+ dest[numBits++] = curPhase; //set first read bit
+ for (i = firstFullWave + fullWaveLen - 1; i < *size-3; i++){
+ //top edge of wave = start of new wave
+ if (dest[i]+fc < dest[i+1] && dest[i+1] >= dest[i+2]){
+ if (waveStart == 0) {
+ waveStart = i+1;
+ waveLenCnt = 0;
+ avgWaveVal = dest[i+1];
+ } else { //waveEnd
+ waveEnd = i+1;
+ waveLenCnt = waveEnd-waveStart;
+ lastAvgWaveVal = avgWaveVal/waveLenCnt;
+ if (waveLenCnt > fc){
+ //PrintAndLog("DEBUG: avgWaveVal: %d, waveSum: %d",lastAvgWaveVal,avgWaveVal);
+ //this wave is a phase shift
+ //PrintAndLog("DEBUG: phase shift at: %d, len: %d, nextClk: %d, i: %d, fc: %d",waveStart,waveLenCnt,lastClkBit+*clock-tol,i+1,fc);
+ if (i+1 >= lastClkBit + *clock - tol){ //should be a clock bit
+ curPhase ^= 1;
+ dest[numBits++] = curPhase;
+ lastClkBit += *clock;
+ } else if (i < lastClkBit+10+fc){
+ //noise after a phase shift - ignore
+ } else { //phase shift before supposed to based on clock
+ errCnt++;
+ dest[numBits++] = 7;
+ }
+ } else if (i+1 > lastClkBit + *clock + tol + fc){
+ lastClkBit += *clock; //no phase shift but clock bit
+ dest[numBits++] = curPhase;
+ }
+ avgWaveVal = 0;
+ waveStart = i+1;
+ }
+ }
+ avgWaveVal += dest[i+1];
+ }
+ *size = numBits;
+ return errCnt;
+}
projects / proxmark3-svn / blobdiff