// otherwise could be a void with no arguments
//set defaults
uint32_t i = 0;
- if (BitStream[1]>1){ //allow only 1s and 0s
- // PrintAndLog("no data found");
- return 0;
- }
+ if (BitStream[1]>1) return 0; //allow only 1s and 0s
+
// 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};
}
//by marshmellow
-//takes 3 arguments - clock, invert, maxErr 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 maxErr)
-{
- size_t i;
- int start = DetectASKClock(BinStream, *size, clk, 20); //clock default
- if (*clk==0 || start < 0) return -3;
- if (*invert != 1) *invert=0;
- uint8_t initLoopMax = 255;
- if (initLoopMax > *size) initLoopMax = *size;
- // Detect high and lows
- // 25% fuzz 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
-
- // PrintAndLog("DEBUG - valid high: %d - valid low: %d",high,low);
- int lastBit = 0; //set first clock check
- uint16_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
- size_t iii = 0;
- //if 0 errors allowed then only try first 2 clock cycles as we want a low tolerance
- if (!maxErr) initLoopMax = *clk * 2;
- uint16_t errCnt = 0, MaxBits = 512;
- uint16_t bestStart = start;
- uint16_t bestErrCnt = 0;
- // PrintAndLog("DEBUG - lastbit - %d",lastBit);
- // if best start position not already found by detect clock then
- if (start <= 0 || start > initLoopMax){
- bestErrCnt = maxErr+1;
- // loop to find first wave that works
- for (iii=0; iii < initLoopMax; ++iii){
- // if no peak skip
- if (BinStream[iii] < high && BinStream[iii] > low) continue;
-
- lastBit = iii - *clk;
- // loop through to see if this start location works
- for (i = iii; i < *size; ++i) {
- if ((i-lastBit) > (*clk-tol) && (BinStream[i] >= high || BinStream[i] <= low)) {
- lastBit += *clk;
- } else if ((i-lastBit) > (*clk+tol)) {
- errCnt++;
- lastBit += *clk;
- }
- if ((i-iii) > (MaxBits * *clk) || errCnt > maxErr) break; //got plenty of bits or too many errors
- }
- //we got more than 64 good bits and not all errors
- if ((((i-iii)/ *clk) > (64)) && (errCnt<=maxErr)) {
- //possible good read
- if (!errCnt || errCnt < bestErrCnt){
- bestStart = iii; //set this as new best run
- bestErrCnt = errCnt;
- if (!errCnt) break; //great read - finish
- }
- }
- errCnt = 0;
- }
- }
- if (bestErrCnt > maxErr){
- *invert = bestStart;
- *clk = iii;
- return -1;
- }
- //best run is good enough set to best run and set overwrite BinStream
- lastBit = bestStart - *clk;
- errCnt = 0;
- for (i = bestStart; i < *size; ++i) {
- if ((BinStream[i] >= high) && ((i-lastBit) > (*clk-tol))){
- //high found and we are expecting a bar
- lastBit += *clk;
- BinStream[bitnum++] = *invert;
- } else if ((BinStream[i] <= low) && ((i-lastBit) > (*clk-tol))){
- //low found and we are expecting a bar
- lastBit += *clk;
- BinStream[bitnum++] = *invert ^ 1;
- } else if ((i-lastBit)>(*clk+tol)){
- //should have hit a high or low based on clock!!
- //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;
- errCnt++;
- }
- lastBit += *clk;//skip over error
- }
- if (bitnum >= MaxBits) break;
- }
- *size = bitnum;
- return bestErrCnt;
-}
-
-//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 10 and 01 and manchester decode
-//run through 2 times and take least errCnt
-int manrawdecode(uint8_t * BitStream, size_t *size)
-{
- uint16_t bitnum=0, MaxBits = 512, errCnt = 0;
- size_t i, ii;
- uint16_t bestErr = 1000, bestRun = 0;
- if (size == 0) return -1;
- for (ii=0;ii<2;++ii){
- for (i=ii; i<*size-2; i+=2)
- if (BitStream[i]==BitStream[i+1])
- errCnt++;
-
- if (bestErr>errCnt){
- bestErr=errCnt;
- bestRun=ii;
- }
- errCnt=0;
- }
- if (bestErr<20){
- for (i=bestRun; 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;
- }
- if(bitnum>MaxBits) break;
- }
- *size=bitnum;
- }
- return bestErr;
-}
-
-//by marshmellow
-//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++]=77;
- errCnt++;
- }
- if((BitStream[i]==1 && BitStream[i+1]==0) || (BitStream[i]==0 && BitStream[i+1]==1)){
- BitStream[bitnum++]=1^invert;
- } else if((BitStream[i]==0 && BitStream[i+1]==0) || (BitStream[i]==1 && BitStream[i+1]==1)){
- BitStream[bitnum++]=invert;
- } else {
- BitStream[bitnum++]=77;
- errCnt++;
- }
- if(bitnum>MaxBits) break;
- }
- *size=bitnum;
- return errCnt;
-}
-
-//by marshmellow
-void askAmp(uint8_t *BitStream, size_t size)
-{
- int shift = 127;
- int shiftedVal=0;
- for(size_t i = 1; i<size; i++){
- if (BitStream[i]-BitStream[i-1]>=30) //large jump up
- shift=127;
- else if(BitStream[i]-BitStream[i-1]<=-20) //large jump down
- shift=-127;
-
- shiftedVal=BitStream[i]+shift;
-
- if (shiftedVal>255)
- shiftedVal=255;
- else if (shiftedVal<0)
- shiftedVal=0;
- BitStream[i-1] = shiftedVal;
- }
- return;
-}
-
-// demodulates strong heavily clipped samples
+//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;
- //PrintAndLog("clk: %d", clk);
for (size_t i=0; i < *size; i++){
if (BinStream[i] >= high && waveHigh){
smplCnt++;
if (smplCnt > clk-(clk/4)-1) { //full clock
if (smplCnt > clk + (clk/4)+1) { //too many samples
errCnt++;
- BinStream[bitCnt++]=77;
+ BinStream[bitCnt++]=7;
} else if (waveHigh) {
BinStream[bitCnt++] = invert;
BinStream[bitCnt++] = invert;
}
//by marshmellow
-//takes 3 arguments - clock, invert and maxErr as integers
-//attempts to demodulate ask only
-int askrawdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr, uint8_t amp)
+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, 20); //clock default
- if (*clk==0 || start < 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);
uint8_t initLoopMax = 255;
- if (initLoopMax > *size) initLoopMax=*size;
+ 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 -1; //just noise
+ return -2; //just noise
+ size_t errCnt = 0;
// if clean clipped waves detected run alternate demod
- if (DetectCleanAskWave(BinStream, *size, high, low))
- return cleanAskRawDemod(BinStream, size, *clk, *invert, high, low);
+ if (DetectCleanAskWave(BinStream, *size, high, low)) {
+ errCnt = cleanAskRawDemod(BinStream, size, *clk, *invert, high, low);
+ if (askType) //askman
+ return manrawdecode(BinStream, size, 0);
+ else //askraw
+ return errCnt;
+ }
- int lastBit = 0; //set first clock check - can go negative
- size_t i, iii = 0;
- size_t errCnt = 0, bitnum = 0; //output counter
+ int lastBit; //set first clock check - can go negative
+ size_t i, bitnum = 0; //output counter
uint8_t midBit = 0;
- size_t bestStart = start, bestErrCnt = 0; //(*size/1000);
+ 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 = 1024;
+ lastBit = start - *clk;
- //if 0 errors allowed then only try first 2 clock cycles as we want a low tolerance
- if (!maxErr) initLoopMax = *clk * 2;
- //if best start not already found by detectclock
- if (start <= 0 || start > initLoopMax){
- bestErrCnt = maxErr+1;
- //PrintAndLog("DEBUG - lastbit - %d",lastBit);
- //loop to find first wave that works
- for (iii=0; iii < initLoopMax; ++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 (i-lastBit > *clk && (BinStream[i] >= high || BinStream[i] <= low)){
- lastBit += *clk;
- midBit = 0;
- } else if (i-lastBit > (*clk/2) && midBit == 0) {
- midBit = 1;
- } else if ((i-lastBit) > *clk) {
- //should have hit a high or low based on clock!!
- //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);
- errCnt++;
- lastBit += *clk;//skip over until hit too many errors
- if (errCnt > maxErr)
- break;
- }
- if ((i-iii)>(MaxBits * *clk)) break; //got enough bits
- }
- //we got more than 64 good bits and not all errors
- if ((((i-iii)/ *clk) > 64) && (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;
- }
- }
- errCnt=0;
- }
- }
- }
- if (bestErrCnt > maxErr){
- *invert = bestStart;
- *clk = iii;
- return -1;
- }
- //best run is good enough - set to best run and overwrite BinStream
- lastBit = bestStart - *clk - 1;
- errCnt = 0;
-
- for (i = bestStart; i < *size; ++i) {
- if (i - lastBit > *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 {
+ } else if (i-lastBit >= *clk+tol) {
if (bitnum > 0) {
- BinStream[bitnum++]=77;
+ BinStream[bitnum++]=7;
errCnt++;
}
+ } else { //in tolerance - looking for peak
+ continue;
}
midBit = 0;
lastBit += *clk;
- } else if (i-lastBit > (*clk/2) && midBit == 0){
+ } 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 {
-
+ } else if (i-lastBit >= *clk/2+tol) {
BinStream[bitnum] = BinStream[bitnum-1];
bitnum++;
+ } else { //in tolerance - looking for peak
+ continue;
}
midBit = 1;
}
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, 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 (bestErr>errCnt){
+ bestErr=errCnt;
+ bestRun=ii;
+ }
+ errCnt=0;
+ }
+ //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;
+ }
+ if(bitnum>MaxBits) break;
+ }
+ *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 = 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^invert;
+ } else if((BitStream[i]==0 && BitStream[i+1]==0) || (BitStream[i]==1 && BitStream[i+1]==1)){
+ BitStream[bitnum++]=invert;
+ } else {
+ BitStream[bitnum++]=7;
+ errCnt++;
+ }
+ if(bitnum>MaxBits) break;
+ }
+ *size=bitnum;
+ return errCnt;
+}
+
+// by marshmellow
// demod gProxIIDemod
// error returns as -x
// success returns start position in BitStream
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
// 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
//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
+ if (LastSample > (fchigh-2) && preLastSample < (fchigh-1)){
+ dest[numBits-1]=1; //correct last 9 wave surrounded by 8 waves
+ }
dest[numBits++]=1;
- } else if ((idx-last_transition) > (fchigh+1) && !numBits) { //12 + and first bit = garbage
+
+ } else if (currSample > (fchigh+1) && !numBits) { //12 + and first bit = 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;
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++)
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;
return (int) startIdx;
}
return -5;
+}
+
+// by marshmellow
+// find viking preamble 0xF200 in already demoded data
+int VikingDemod_AM(uint8_t *dest, size_t *size) {
+ if (justNoise(dest, *size)) return -1;
+ //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
+
+ if (*size != 64) return -5;
+ //return start position
+ return (int) startIdx;
}
// 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;
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 (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;
}
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)
return (int)startIdx;
}
-
-uint8_t DetectCleanAskWave(uint8_t dest[], size_t size, int high, int low)
+// 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)
{
uint16_t allPeaks=1;
uint16_t cntPeaks=0;
- size_t loopEnd = 572;
+ size_t loopEnd = 512+60;
if (loopEnd > size) loopEnd = size;
for (size_t i=60; i<loopEnd; i++){
if (dest[i]>low && dest[i]<high)
// by marshmellow
// to help detect clocks on heavily clipped samples
-// based on counts between zero crossings
-int DetectStrongAskClock(uint8_t dest[], size_t size)
+// based on count of low to low
+int DetectStrongAskClock(uint8_t dest[], size_t size, uint8_t high, uint8_t low)
{
- int clk[]={0,8,16,32,40,50,64,100,128};
- size_t idx = 40;
- uint8_t high=0;
- size_t cnt = 0;
- size_t highCnt = 0;
- size_t highCnt2 = 0;
- for (;idx < size; idx++){
- if (dest[idx]>128) {
- if (!high){
- high=1;
- if (cnt > highCnt){
- if (highCnt != 0) highCnt2 = highCnt;
- highCnt = cnt;
- } else if (cnt > highCnt2) {
- highCnt2 = cnt;
- }
- cnt=1;
- } else {
- cnt++;
- }
- } else if (dest[idx] <= 128){
- if (high) {
- high=0;
- if (cnt > highCnt) {
- if (highCnt != 0) highCnt2 = highCnt;
- highCnt = cnt;
- } else if (cnt > highCnt2) {
- highCnt2 = cnt;
- }
- cnt=1;
- } else {
- cnt++;
- }
- }
+ uint8_t fndClk[] = {8,16,32,40,50,64,128};
+ size_t startwave;
+ size_t i = 0;
+ 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;
}
- uint8_t tol;
- for (idx=8; idx>0; idx--){
- tol = clk[idx]/8;
- if (clk[idx] >= highCnt - tol && clk[idx] <= highCnt + tol)
- return clk[idx];
- if (clk[idx] >= highCnt2 - tol && clk[idx] <= highCnt2 + tol)
- return clk[idx];
+ // set clock
+ for (uint8_t clkCnt = 0; clkCnt<7; clkCnt++) {
+ if (minClk >= fndClk[clkCnt]-(fndClk[clkCnt]/8) && minClk <= fndClk[clkCnt]+1)
+ return fndClk[clkCnt];
}
- return -1;
+ return 0;
}
// by marshmellow
// 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)
{
- size_t i=0;
- uint8_t clk[]={8,16,32,40,50,64,100,128,255};
+ 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) return -1; //not enough samples
- //if we already have a valid clock quit
-
- for (;i<8;++i)
- if (clk[i] == *clock) return 0;
+
+ //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
int peak, low;
if (getHiLo(dest, loopCnt, &peak, &low, 75, 75) < 1) return -1;
//test for large clean peaks
- if (DetectCleanAskWave(dest, size, peak, low)==1){
- int ans = DetectStrongAskClock(dest, size);
- for (i=7; i>0; i--){
- if (clk[i] == ans) {
- *clock = ans;
- return 0;
+ if (!clockFnd){
+ if (DetectCleanAskWave(dest, size, peak, low)==1){
+ int ans = DetectStrongAskClock(dest, size, peak, low);
+ 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]
+ }
}
}
}
+
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 < 8; clkCnt++){
- if (clk[clkCnt] == 32){
+ for(; clkCnt < clkEnd; clkCnt++){
+ if (clk[clkCnt] <= 32){
tol=1;
}else{
tol=0;
}
- if (!maxErr) loopCnt=clk[clkCnt]*2;
+ //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)
+ //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++;
}
}
- //if we found no errors then we can stop here
+ //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);
- if(errCnt==0 && clkCnt<6) {
- *clock = clk[clkCnt];
+ 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
}
}
}
- uint8_t iii=0;
+ uint8_t iii;
uint8_t best=0;
- for (iii=0; iii<8; ++iii){
+ 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 (bestErr[best] > maxErr) return -1;
- *clock = clk[best];
+ //if (bestErr[best] > maxErr) return -1;
+ if (!clockFnd) *clock = clk[best];
return bestStart[best];
}
size_t i=1;
uint8_t lastBit=BitStream[0];
for (; i<size; i++){
- if (BitStream[i]==77){
+ if (BitStream[i]==7){
//ignore errors
} else if (lastBit!=BitStream[i]){
lastBit=BitStream[i];
if (ignoreCnt == 0){
bitHigh = 0;
if (errBitHigh == 1){
- dest[bitnum++] = 77;
+ dest[bitnum++] = 7;
errCnt++;
}
errBitHigh=0;
//noise after a phase shift - ignore
} else { //phase shift before supposed to based on clock
errCnt++;
- dest[numBits++] = 77;
+ dest[numBits++] = 7;
}
} else if (i+1 > lastClkBit + *clock + tol + fc){
lastClkBit += *clock; //no phase shift but clock bit
projects / proxmark3-svn / blobdiff