//-----------------------------------------------------------------------------
// Low frequency demod/decode commands
//-----------------------------------------------------------------------------
-
-#include <stdlib.h>
#include "lfdemod.h"
-#include <string.h>
//un_comment to allow debug print calls when used not on device
void dummy(char *fmt, ...){}
+void dummy_sgc (int clock, int startidx) {}
#ifndef ON_DEVICE
-#include "ui.h"
-#include "cmdparser.h"
-#include "cmddata.h"
-#define prnt PrintAndLog
+# include "ui.h" // plotclock, plotclockstartindex
+# include "cmdparser.h"
+# include "cmddata.h"
+# define prnt PrintAndLog
+# define sgc SetGraphClock
+void SetGraphClock(int clock, int startidx){
+ PlotClock = clock;
+ PlockClockStartIndex = startidx;
+}
#else
- uint8_t g_debugMode=0;
-#define prnt dummy
+ uint8_t g_debugMode = 0;
+# define prnt dummy
+# define sgc dummy_sgc
#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;
+//test samples are not just noise
+uint8_t justNoise(uint8_t *bits, size_t size) {
+ #define THRESHOLD 123
+ uint8_t val = 1;
+ for(size_t idx = 0; idx < size && val; idx++)
+ val = bits[idx] < THRESHOLD;
+ return val;
}
//by marshmellow
for (uint8_t i = 0; i < bitLen; i++){
ans ^= ((bits >> i) & 1);
}
- //PrintAndLog("DEBUG: ans: %d, ptype: %d",ans,pType);
+ if (g_debugMode) prnt("DEBUG: ans: %d, ptype: %d, bits: %08X",ans,pType,bits);
return (ans == pType);
}
{
uint32_t parityWd = 0;
size_t j = 0, bitCnt = 0;
- for (int word = 0; word < (bLen); word+=pLen){
+ 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]);
}
+ if (word+pLen > bLen) break;
+
j--; // overwrite parity with next data
// if parity fails then return 0
switch (pType) {
- case 3: if (BitStream[j]==1) return 0; break; //should be 0 spacer bit
- case 2: if (BitStream[j]==0) return 0; break; //should be 1 spacer bit
- default: //test parity
- if (parityTest(parityWd, pLen, pType) == 0) return 0; break;
+ case 3: if (BitStream[j]==1) { return 0; } break; //should be 0 spacer bit
+ case 2: if (BitStream[j]==0) { return 0; } break; //should be 1 spacer bit
+ default: if (parityTest(parityWd, pLen, pType) == 0) { return 0; } break; //test parity
}
- bitCnt+=(pLen-1);
+ bitCnt += (pLen-1);
parityWd = 0;
}
// if we got here then all the parities passed
return num;
}
+//by marshmellow
+// search for given preamble in given BitStream and return success=1 or fail=0 and startIndex (where it was found)
+bool preambleSearch(uint8_t *BitStream, uint8_t *preamble, size_t pLen, size_t *size, size_t *startIdx){
+ return preambleSearchEx(BitStream, preamble, pLen, size, startIdx, false);
+}
//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)
+// param @findone: look for a repeating preamble or only the first.
+// em4x05/4x69 only sends preamble once, so look for it once in the first pLen bits
+bool preambleSearchEx(uint8_t *BitStream, uint8_t *preamble, size_t pLen, size_t *size, size_t *startIdx, bool findone)
{
- uint8_t foundCnt=0;
- for (int idx=0; idx < *size - pLen; idx++){
+ // Sanity check. If preamble length is bigger than bitstream length.
+ if ( *size <= pLen ) return false;
+
+ uint8_t foundCnt = 0;
+ for (int idx = 0; idx < *size - pLen; idx++){
if (memcmp(BitStream+idx, preamble, pLen) == 0){
+ if (g_debugMode) prnt("DEBUG: preamble found at %i", idx);
//first index found
foundCnt++;
if (foundCnt == 1){
*startIdx = idx;
+ if (findone) return true;
}
if (foundCnt == 2){
*size = idx - *startIdx;
- return 1;
+ return true;
}
}
}
- return 0;
+ return false;
+}
+
+// find start of modulating data (for fsk and psk) in case of beginning noise or slow chip startup.
+size_t findModStart(uint8_t dest[], size_t size, uint8_t threshold_value, uint8_t expWaveSize) {
+ size_t i = 0;
+ size_t waveSizeCnt = 0;
+ uint8_t thresholdCnt = 0;
+ bool isAboveThreshold = dest[i++] >= threshold_value;
+ for (; i < size-20; i++ ) {
+ if(dest[i] < threshold_value && isAboveThreshold) {
+ thresholdCnt++;
+ if (thresholdCnt > 2 && waveSizeCnt < expWaveSize+1) break;
+ isAboveThreshold = false;
+ waveSizeCnt = 0;
+ } else if (dest[i] >= threshold_value && !isAboveThreshold) {
+ thresholdCnt++;
+ if (thresholdCnt > 2 && waveSizeCnt < expWaveSize+1) break;
+ isAboveThreshold = true;
+ waveSizeCnt = 0;
+ } else {
+ waveSizeCnt++;
+ }
+ if (thresholdCnt > 10) break;
+ }
+ if (g_debugMode == 2) prnt("DEBUG: threshold Count reached at %u, count: %u",i, thresholdCnt);
+ return i;
}
//by marshmellow
//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)
+// actually, no arguments needed - built this way in case we want this to be a direct call from "data " cmds in the future
+int 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
-
- // 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;
+ // sanity check
+ if (*size < 64) return -3;
+ if (BitStream[1] > 1) return -1;
+
+ uint8_t fmtlen;
*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]);
- }
+
+ // preamble 0111111111
+ // include 0 in front to help get start pos
+ uint8_t preamble[] = {0,1,1,1,1,1,1,1,1,1};
+ if (!preambleSearch(BitStream, preamble, sizeof(preamble), size, startIdx))
+ return -2;
+
+ //XL and normal size.
+ if (*size != 64 && *size != 128) return -3;
+
+ fmtlen = (*size == 128) ? 22 : 10;
+
+ //skip last 4bit parity row for simplicity
+ *size = removeParity(BitStream, *startIdx + sizeof(preamble), 5, 0, fmtlen * 5);
+
+ switch (*size) {
+ case 40: {
+ // std em410x format
+ *hi = 0;
+ *lo = ((uint64_t)(bytebits_to_byte(BitStream, 8)) << 32) | (bytebits_to_byte(BitStream + 8, 32));
+ break;
+ }
+ case 88: {
+ // long em format
+ *hi = (bytebits_to_byte(BitStream, 24));
+ *lo = ((uint64_t)(bytebits_to_byte(BitStream + 24, 32)) << 32) | (bytebits_to_byte(BitStream + 24 + 32, 32));
+ break;
+ }
+ default: return -4;
}
- if (errChk != 0) return 1;
- //skip last 5 bit parity test for simplicity.
- // *size = 64 | 128;
- return 0;
+ return 1;
}
//by marshmellow
//demodulates strong heavily clipped samples
+//RETURN: num of errors. if 0, is ok.
int cleanAskRawDemod(uint8_t *BinStream, size_t *size, int clk, int invert, int high, int low)
{
size_t bitCnt=0, smplCnt=0, errCnt=0;
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++;
if (g_debugMode==2) prnt("DEBUG ASK: Modulation Error at: %u", i);
- BinStream[bitCnt++]=7;
+ BinStream[bitCnt++] = 7;
} else if (waveHigh) {
BinStream[bitCnt++] = invert;
BinStream[bitCnt++] = invert;
//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]=255;
- else if(BitStream[i]-BitStream[i-1]<=-20) //large jump down
- BitStream[i]=0;
+ uint8_t last = 128;
+ for(size_t i = 1; i < size; ++i){
+ if (BitStream[i]-BitStream[i-1] >= 30) //large jump up
+ last = 255;
+ else if(BitStream[i-1] - BitStream[i] >= 20) //large jump down
+ last = 0;
+
+ BitStream[i] = last;
}
- return;
}
//by marshmellow
if (*clk==0 || start < 0) return -3;
if (*invert != 1) *invert = 0;
if (amp==1) askAmp(BinStream, *size);
- if (g_debugMode==2) prnt("DEBUG ASK: clk %d, beststart %d", *clk, start);
+ if (g_debugMode==2) prnt("DEBUG ASK: clk %d, beststart %d, amp %d", *clk, start, amp);
+ sgc(*clk, start);
+
uint8_t initLoopMax = 255;
if (initLoopMax > *size) initLoopMax = *size;
// Detect high and lows
errCnt = cleanAskRawDemod(BinStream, size, *clk, *invert, high, low);
if (askType) //askman
return manrawdecode(BinStream, size, 0);
- else //askraw
- return errCnt;
+ //askraw
+ return errCnt;
}
if (g_debugMode==2) prnt("DEBUG ASK: Weak Wave Detected - using weak wave demod");
*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, uint8_t invert)
-{
- uint16_t bitnum=0, MaxBits = 512, errCnt = 0;
- size_t i, ii;
- uint16_t bestErr = 1000, bestRun = 0;
+int manrawdecode(uint8_t *BitStream, size_t *size, uint8_t invert){
+
+ // sanity check
if (*size < 16) return -1;
+
+ int errCnt = 0, bestErr = 1000;
+ uint16_t bitnum = 0, MaxBits = 512, bestRun = 0;
+ size_t i, k;
+
//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])
+ for (k = 0; k < 2; ++k){
+ for (i = k; i < *size-3; i += 2) {
+ if (BitStream[i] == BitStream[i+1])
errCnt++;
-
- if (bestErr>errCnt){
- bestErr=errCnt;
- bestRun=ii;
}
- errCnt=0;
+ if (bestErr > errCnt){
+ bestErr = errCnt;
+ bestRun = k;
+ }
+ 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;
+ 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;
+ BitStream[bitnum++] = 7;
}
- if(bitnum>MaxBits) break;
+ if (bitnum > MaxBits) break;
}
- *size=bitnum;
+ *size = bitnum;
return bestErr;
}
size_t startIdx=0;
uint8_t preamble[] = {1,1,1,1,1,0};
- uint8_t errChk = preambleSearch(BitStream, preamble, sizeof(preamble), size, &startIdx);
- if (errChk == 0) return -3; //preamble not found
+ if (!preambleSearch(BitStream, preamble, sizeof(preamble), size, &startIdx))
+ 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
{
size_t last_transition = 0;
size_t idx = 1;
- //uint32_t maxVal=0;
if (fchigh==0) fchigh=10;
if (fclow==0) fclow=8;
//set the threshold close to 0 (graph) or 128 std to avoid static
size_t preLastSample = 0;
size_t LastSample = 0;
size_t currSample = 0;
- // sync to first lo-hi transition, and threshold
+ if ( size < 1024 ) return 0; // not enough samples
+
+ //find start of modulating data in trace
+ idx = findModStart(dest, size, threshold_value, fchigh);
// Need to threshold first sample
- // skip 160 samples to allow antenna/samples to settle
- if(dest[160] < threshold_value) dest[0] = 0;
+ if(dest[idx] < threshold_value) dest[0] = 0;
else dest[0] = 1;
+ idx++;
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 anywhere
// between 7 to 11 cycles so fuzz it by treat anything <9 as 8 and anything else as 10
// (could also be fc/5 && fc/7 for fsk1 = 4-9)
- for(idx = 161; idx < size-20; idx++) {
+ for(; idx < size-20; idx++) {
// threshold current value
if (dest[idx] < threshold_value) dest[idx] = 0;
//do nothing with extra garbage
} else if (currSample < (fchigh-1)) { //6-8 = 8 sample waves (or 3-6 = 5)
//correct previous 9 wave surrounded by 8 waves (or 6 surrounded by 5)
- if (LastSample > (fchigh-2) && (preLastSample < (fchigh-1) || preLastSample == 0 )){
+ if (LastSample > (fchigh-2) && (preLastSample < (fchigh-1))){
dest[numBits-1]=1;
}
dest[numBits++]=1;
- } else if (currSample > (fchigh) && !numBits) { //12 + and first bit = unusable garbage
- //do nothing with beginning garbage
+ } else if (currSample > (fchigh+1) && numBits < 3) { //12 + and first two bit = unusable garbage
+ //do nothing with beginning garbage and reset.. should be rare..
+ numBits = 0;
} else if (currSample == (fclow+1) && LastSample == (fclow-1)) { // had a 7 then a 9 should be two 8's (or 4 then a 6 should be two 5's)
dest[numBits++]=1;
} else { //9+ = 10 sample waves (or 6+ = 7)
uint32_t n=1;
for( idx=1; idx < size; idx++) {
n++;
- if (dest[idx]==lastval) continue;
+ if (dest[idx]==lastval) continue; //skip until we hit a transition
//find out how many bits (n) we collected
//if lastval was 1, we have a 1->0 crossing
{
if (justNoise(dest, *size)) return -1;
- size_t numStart=0, size2=*size, startIdx=0;
+ size_t numStart=0, size2 = *size, startIdx=0;
// FSK demodulator
*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
+ if (!preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx))
+ return -3; //preamble not found
numStart = startIdx + sizeof(preamble);
// final loop, go over previously decoded FSK data and manchester decode into usable tag ID
*hi2 = (*hi2<<1)|(*hi>>31);
*hi = (*hi<<1)|(*lo>>31);
//Then, shift in a 0 or one into low
+ *lo <<= 1;
if (dest[idx] && !dest[idx+1]) // 1 0
- *lo=(*lo<<1)|1;
+ *lo |= 1;
else // 0 1
- *lo=(*lo<<1)|0;
+ *lo |= 0;
}
return (int)startIdx;
}
{
if (justNoise(dest, *size)) return -1;
- size_t numStart=0, size2=*size, startIdx=0;
+ 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
+ if (preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx))
+ return -3; //preamble not found
numStart = startIdx + sizeof(preamble);
// final loop, go over previously decoded FSK data and manchester decode into usable tag ID
//Handle the data
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 (! preambleSearch(dest, preamble, sizeof(preamble), &size, &startIdx))
+ 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
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
+ if (!preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx))
+ 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) ^
if ( checkCalc != 0xA8 ) return -5;
if (*size != 64) return -6;
//return start position
- return (int) startIdx;
+ return (int)startIdx;
}
+// by iceman
+// find Visa2000 preamble in already demoded data
+int Visa2kDemod_AM(uint8_t *dest, size_t *size) {
+ if (*size < 96) return -1; //make sure buffer has data
+ size_t startIdx = 0;
+ uint8_t preamble[] = {0,1,0,1,0,1,1,0,0,1,0,0,1,0,0,1,0,1,0,1,0,0,1,1,0,0,1,1,0,0,1,0};
+ if (!preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx))
+ return -2; //preamble not found
+ if (*size != 96) return -3; //wrong demoded size
+ //return start position
+ return (int)startIdx;
+}
+// by iceman
+// find Noralsy preamble in already demoded data
+int NoralsyDemod_AM(uint8_t *dest, size_t *size) {
+ if (*size < 96) return -1; //make sure buffer has data
+ size_t startIdx = 0;
+ uint8_t preamble[] = {1,0,1,1,1,0,1,1,0,0,0,0};
+ if (!preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx))
+ return -2; //preamble not found
+ if (*size != 96) return -3; //wrong demoded size
+ //return start position
+ return (int)startIdx;
+}
// find presco preamble 0x10D in already demoded data
int PrescoDemod(uint8_t *dest, size_t *size) {
- //make sure buffer has data
- if (*size < 64*2) return -2;
-
+ if (*size < 128*2) return -1; //make sure buffer has data
size_t startIdx = 0;
- uint8_t preamble[] = {1,0,0,0,0,1,1,0,1,0,0,0,0,0,0,0,0,0,0,0};
- uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
- if (errChk == 0) return -4; //preamble not found
+ uint8_t preamble[] = {0,0,0,1,0,0,0,0,1,1,0,1,0,0,0,0,0,0,0,0,0,0,0};
+ if (!preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx))
+ return -2; //preamble not found
+ if (*size != 128) return -3; //wrong demoded size
//return start position
- return (int) startIdx;
+ 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;
-
+int FDXBdemodBI(uint8_t *dest, size_t *size) {
+ if (*size < 128*2) return -1; //make sure buffer has enough data
size_t startIdx = 0;
uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,1};
+ if (!preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx))
+ return -2; //preamble not found
+ if (*size != 128) return -3; //wrong demoded size
+ //return start position
+ return (int)startIdx;
+}
- uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
- if (errChk == 0) return -2; //preamble not found
+// ASK/Diphase fc/64 (inverted Biphase)
+// Note: this i s not a demod, this is only a detection
+// the parameter *dest needs to be demoded before call
+// 0xFFFF preamble, 64bits
+int JablotronDemod(uint8_t *dest, size_t *size){
+ if (*size < 64*2) return -1; //make sure buffer has enough data
+ size_t startIdx = 0;
+ uint8_t preamble[] = {1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0};
+ if (!preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx))
+ return -2; //preamble not found
+ if (*size != 64) return -3; // wrong demoded size
+
+ uint8_t checkchksum = 0;
+ for (int i=16; i < 56; i += 8) {
+ checkchksum += bytebits_to_byte(dest+startIdx+i,8);
+ }
+ checkchksum ^= 0x3A;
+ uint8_t crc = bytebits_to_byte(dest+startIdx+56, 8);
+ if ( checkchksum != crc ) return -5;
return (int)startIdx;
}
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 (!preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx))
+ return -4; //preamble not found
if (*size != 96) return -5;
return (int)startIdx;
}
// 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
+ uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,1};
+ if (!preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx))
+ return -4; //preamble not found
if (*size != 128) return -3;
return (int)startIdx;
}
-// find presco preamble 0x10D in already demoded data
+// find nedap preamble in already demoded data
int NedapDemod(uint8_t *dest, size_t *size) {
//make sure buffer has data
if (*size < 128) return -3;
size_t startIdx = 0;
//uint8_t preamble[] = {1,1,1,1,1,1,1,1,1,0,0,0,1};
uint8_t preamble[] = {1,1,1,1,1,1,1,1,1,0};
- uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
- if (errChk == 0) return -4; //preamble not found
+ if (!preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx))
+ return -4; //preamble not found
+ return (int) startIdx;
+}
+
+// Find IDTEC PSK1, RF Preamble == 0x4944544B, Demodsize 64bits
+// by iceman
+int IdteckDemodPSK(uint8_t *dest, size_t *size) {
+ //make sure buffer has data
+ if (*size < 64*2) return -1;
+ size_t startIdx = 0;
+ uint8_t preamble[] = {0,1,0,0,1,0,0,1,0,1,0,0,0,1,0,0,0,1,0,1,0,1,0,0,0,1,0,0,1,0,1,1};
+ if (!preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx))
+ return -2; //preamble not found
+ if (*size != 64) return -3; // wrong demoded size
return (int) startIdx;
}
// 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)
+int DetectStrongAskClock(uint8_t dest[], size_t size, uint8_t high, uint8_t low, int *clock)
{
- uint8_t fndClk[] = {8,16,32,40,50,64,128};
+ uint8_t clocks[] = {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
+ int shortestWaveIdx = 0;
+ // 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))
while ((dest[i] > low) && (i < size))
++i;
//get minimum measured distance
- if (i-startwave < minClk && i < size)
+ if (i-startwave < minClk && i < size) {
minClk = i - startwave;
+ shortestWaveIdx = 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];
+ if (minClk >= clocks[clkCnt]-(clocks[clkCnt]/8) && minClk <= clocks[clkCnt]+1) {
+ *clock = clocks[clkCnt];
+ return shortestWaveIdx;
+ }
}
return 0;
}
// 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=1;
+ 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
+ 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)
+ uint8_t clockFnd = 0;
+ for (; i < clkEnd; ++i)
if (clk[i] == *clock) clockFnd = i;
//clock found but continue to find best startpos
//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]
- }
+ int ans = DetectStrongAskClock(dest, size, peak, low, clock);
+ if (g_debugMode==2) prnt("DEBUG ASK: detectaskclk Clean Ask Wave Detected: clk %i, ShortestWave: %i", clock ,ans);
+ if (ans > 0){
+ return ans; // return shortest wave start pos
}
}
}
size_t errCnt = 0;
size_t arrLoc, loopEnd;
- if (clockFnd>0) {
+ if (clockFnd > 0) {
clkCnt = clockFnd;
clkEnd = clockFnd+1;
+ } else {
+ clkCnt = 1;
}
- else clkCnt=1;
//test each valid clock from smallest to greatest to see which lines up
- for(; clkCnt < clkEnd; clkCnt++){
- if (clk[clkCnt] <= 32){
+ for (; clkCnt < clkEnd; clkCnt++) {
+ if (clk[clkCnt] <= 32) {
tol=1;
- }else{
+ } 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;
+ 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 few clocks)
for (ii=0; ii < loopCnt; ii++){
if (dest[ii] < peak && dest[ii] > low) continue;
- errCnt=0;
+ 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){
}
//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 (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;
+ if (errCnt < bestErr[clkCnt]) {
+ bestErr[clkCnt] = errCnt;
+ bestStart[clkCnt] = ii;
}
}
}
- 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;
+ uint8_t k;
+ uint8_t best = 0;
+ for (k=1; k < clkEnd; ++k){
+ if (bestErr[k] < bestErr[best]){
+ if (bestErr[k] == 0) bestErr[k]=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 ( (size/clk[best])/bestErr[best] < (size/clk[k])/bestErr[k] ){
+ best = k;
}
}
- 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]);
+ if (g_debugMode == 2) prnt("DEBUG ASK: clk %d, # Errors %d, Current Best Clk %d, bestStart %d", clk[k], bestErr[k], clk[best], bestStart[best]);
}
if (!clockFnd) *clock = clk[best];
+
return bestStart[best];
}
+int DetectPSKClock(uint8_t dest[], size_t size, int clock) {
+ int firstPhaseShift = 0;
+ return DetectPSKClock_ext(dest, size, clock, &firstPhaseShift);
+}
+
//by marshmellow
//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)
-{
- uint8_t clk[]={255,16,32,40,50,64,100,128,255}; //255 is not a valid clock
+int DetectPSKClock_ext(uint8_t dest[], size_t size, int clock, int *firstPhaseShift) {
+ 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;
+ if (size < 160+20) return 0;
+ // size must be larger than 20 here, and 160 later on.
+ if (size < loopCnt) loopCnt = size-20;
+
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};
+ 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++){
+ for (i=160; i < loopCnt; i++){
if (dest[i] < dest[i+1] && dest[i+1] >= dest[i+2]){
if (waveStart == 0) {
waveStart = i+1;
}
}
}
- if (g_debugMode ==2) prnt("DEBUG PSK: firstFullWave: %d, waveLen: %d",firstFullWave,fullWaveLen);
+ *firstPhaseShift = firstFullWave;
+ 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--){
+ for (clkCnt=7; clkCnt >= 1 ; clkCnt--){
lastClkBit = firstFullWave; //set end of wave as clock align
waveStart = 0;
errCnt=0;
}
}
}
- if (errCnt == 0){
- return clk[clkCnt];
- }
- if (errCnt <= bestErr[clkCnt]) bestErr[clkCnt]=errCnt;
- if (peakcnt > peaksdet[clkCnt]) peaksdet[clkCnt]=peakcnt;
+ 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]) {
+ 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];
return lowestTransition;
}
+int DetectNRZClock(uint8_t dest[], size_t size, int clock) {
+ int bestStart = 0;
+ return DetectNRZClock_ext(dest, size, clock, &bestStart);
+}
+
//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};
+int DetectNRZClock_ext(uint8_t dest[], size_t size, int clock, int *clockStartIdx) {
+ 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;
+
+ if (size < 20) return 0;
+ // size must be larger than 20 here
+ if (size < loopCnt) loopCnt = size-20;
//get high and low peak
int peak, low;
if (!firstpeak) continue;
smplCnt++;
} else {
- firstpeak=true;
+ firstpeak = true;
if (smplCnt > 6 ){
if (maxPeak > smplCnt){
maxPeak = smplCnt;
}
peakcnt++;
//prnt("maxPk: %d, smplCnt: %d, peakcnt: %d",maxPeak,smplCnt,peakcnt);
- smplCnt=0;
+ smplCnt = 0;
}
}
}
uint8_t ignoreWindow = 4;
bool lastPeakHigh = 0;
int lastBit = 0;
- peakcnt=0;
+ int bestStart[] = {0,0,0,0,0,0,0,0,0};
+ 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 (dest[i] >= peak || dest[i] <= low) {
//if same peak don't count it
if ((dest[i] >= peak && !lastPeakHigh) || (dest[i] <= low && lastPeakHigh)) {
- peakcnt++;
+ peakcnt++;
}
lastPeakHigh = (dest[i] >= peak);
bitHigh = true;
}
//else if not a clock bit and no peaks
} else if (dest[i] < peak && dest[i] > low){
- if (ignoreCnt==0){
+ if (ignoreCnt == 0){
bitHigh=false;
- if (errBitHigh==true) peakcnt--;
+ if (errBitHigh==true)
+ peakcnt--;
errBitHigh=false;
} else {
ignoreCnt--;
errBitHigh=true;
}
}
- if(peakcnt>peaksdet[clkCnt]) {
- peaksdet[clkCnt]=peakcnt;
+ if (peakcnt > peaksdet[clkCnt]) {
+ bestStart[clkCnt]=ii;
+ peaksdet[clkCnt] = peakcnt;
}
}
}
}
- 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;
- }
- } else if (peaksdet[iii] > peaksdet[best]){
- best = iii;
+
+ uint8_t best = 0;
+ for (int m = 7; m > 0; m--){
+ if ((peaksdet[m] >= (peaksdet[best]-1)) && (peaksdet[m] <= peaksdet[best]+1) && lowestTransition) {
+ if (clk[m] > (lowestTransition - (clk[m]/8)) && clk[m] < (lowestTransition + (clk[m]/8))) {
+ best = m;
+ }
+ } else if (peaksdet[m] > peaksdet[best]){
+ best = m;
}
- 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);
+ if (g_debugMode==2) prnt("DEBUG NRZ: Clk: %d, peaks: %d, maxPeak: %d, bestClk: %d, lowestTrs: %d", clk[m], peaksdet[m], maxPeak, clk[best], lowestTransition);
}
-
+ *clockStartIdx = bestStart[best];
return clk[best];
}
// 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;
+void psk1TOpsk2(uint8_t *bits, size_t size) {
+ uint8_t lastBit = bits[0];
+ for (size_t i = 1; i < size; i++){
+ //ignore errors
+ if (bits[i] == 7) continue;
+
+ if (lastBit != bits[i]){
+ lastBit = bits[i];
+ bits[i] = 1;
} else {
- BitStream[i]=0;
+ bits[i] = 0;
}
}
- 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;
+void psk2TOpsk1(uint8_t *bits, size_t size) {
+ uint8_t phase = 0;
+ for (size_t i = 0; i < size; i++){
+ if (bits[i] == 1){
+ phase ^= 1;
}
- BitStream[i]=phase;
+ bits[i] = phase;
}
- return;
}
// redesigned by marshmellow adjusted from existing decode functions
return 0;
}
+uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fcLow) {
+ int firstClockEdge = 0;
+ return detectFSKClk_ext(BitStream, size, fcHigh, fcLow, &firstClockEdge);
+}
+
//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 detectFSKClk_ext(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fcLow, int *firstClockEdge) {
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};
fcCounter=0;
rfCounter=0;
firstBitFnd=0;
- //PrintAndLog("DEBUG: fcTol: %d",fcTol);
+ //prnt("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])
continue;
// else new peak
// if we got less than the small fc + tolerance then set it to the small fc
- if (fcCounter < fcLow+fcTol)
+ // if it is inbetween set it to the last counter
+ if (fcCounter < fcHigh && fcCounter > fcLow)
+ fcCounter = lastFCcnt;
+ else if (fcCounter < fcLow+fcTol)
fcCounter = fcLow;
else //set it to the large fc
fcCounter = fcHigh;
}
}
if (rfCounter > 0 && rfLensFnd < 15){
- //PrintAndLog("DEBUG: rfCntr %d, fcCntr %d",rfCounter,fcCounter);
+ //prnt("DEBUG: rfCntr %d, fcCntr %d",rfCounter,fcCounter);
rfCnts[rfLensFnd]++;
rfLens[rfLensFnd++] = rfCounter;
}
} else {
+ *firstClockEdge = i;
firstBitFnd++;
}
rfCounter=0;
}
}
- if (ii<0) return 0; // oops we went too far
+ if (ii<2) return 0; // oops we went too far
return clk[ii];
}
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 lastFCcnt = 0;
uint8_t fcCounter = 0;
size_t i;
- if (size == 0) return 0;
+ if (size < 180) return 0;
// prime i to first up transition
for (i = 160; i < size-20; i++)
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);
+ size_t i=0, waveStart=1, waveEnd=0, firstFullWave=0, lastClkBit=0;
+ uint16_t fc=0, fullWaveLen=0, tol=1;
+ uint16_t errCnt=0, waveLenCnt=0, errCnt2=0;
+ fc = countFC(dest, *size, 1);
+ uint8_t fc2 = fc >> 8;
+ if (fc2 == 10) return -1; //fsk found - quit
+ fc = fc & 0xFF;
if (fc!=2 && fc!=4 && fc!=8) return -1;
- //PrintAndLog("DEBUG: FC: %d",fc);
+ //prnt("DEBUG: FC: %d",fc);
*clock = DetectPSKClock(dest, *size, *clock);
if (*clock == 0) return -1;
- int avgWaveVal=0, lastAvgWaveVal=0;
+
+ //find start of modulating data in trace
+ uint8_t threshold_value = 123; //-5
+ i = findModStart(dest, *size, threshold_value, fc);
+
//find first phase shift
- for (i=0; i<loopCnt; i++){
+ int avgWaveVal=0, lastAvgWaveVal=0;
+ waveStart = i;
+ for (; i<loopCnt; i++){
+ // find peak
if (dest[i]+fc < dest[i+1] && dest[i+1] >= dest[i+2]){
waveEnd = i+1;
- //PrintAndLog("DEBUG: waveEnd: %d",waveEnd);
+ if (g_debugMode == 2) prnt("DEBUG PSK: waveEnd: %u, waveStart: %u",waveEnd, waveStart);
waveLenCnt = waveEnd-waveStart;
- if (waveLenCnt > fc && waveStart > fc && !(waveLenCnt > fc+2)){ //not first peak and is a large wave but not out of whack
+ if (waveLenCnt > fc && waveStart > fc && !(waveLenCnt > fc+3)){ //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
+ //if average wave value is > graph 0 then it is an up wave or a 1 (could cause inverting)
+ if (lastAvgWaveVal > threshold_value) curPhase ^= 1;
break;
}
waveStart = i+1;
//set start of wave as clock align
lastClkBit = firstFullWave;
if (g_debugMode==2) prnt("DEBUG PSK: firstFullWave: %u, waveLen: %u",firstFullWave,fullWaveLen);
- if (g_debugMode==2) prnt("DEBUG: clk: %d, lastClkBit: %u, fc: %u", *clock, lastClkBit,(unsigned int) fc);
+ if (g_debugMode==2) prnt("DEBUG PSK: clk: %d, lastClkBit: %u, fc: %u", *clock, lastClkBit,(unsigned int) fc);
waveStart = 0;
dest[numBits++] = curPhase; //set first read bit
for (i = firstFullWave + fullWaveLen - 1; i < *size-3; i++){
waveLenCnt = waveEnd-waveStart;
lastAvgWaveVal = avgWaveVal/waveLenCnt;
if (waveLenCnt > fc){
- //PrintAndLog("DEBUG: avgWaveVal: %d, waveSum: %d",lastAvgWaveVal,avgWaveVal);
+ //prnt("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);
+ //prnt("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;
} else if (i+1 > lastClkBit + *clock + tol + fc){
lastClkBit += *clock; //no phase shift but clock bit
dest[numBits++] = curPhase;
+ } else if (waveLenCnt < fc - 1) { //wave is smaller than field clock (shouldn't happen often)
+ errCnt2++;
+ if(errCnt2 > 101) return errCnt2;
}
avgWaveVal = 0;
waveStart = i+1;
return errCnt;
}
+bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) {
+ size_t ststart = 0, stend = 0;
+ return DetectST_ext(buffer, size, foundclock, &ststart, &stend);
+}
+
//by marshmellow
//attempt to identify a Sequence Terminator in ASK modulated raw wave
-bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) {
+bool DetectST_ext(uint8_t buffer[], size_t *size, int *foundclock, size_t *ststart, size_t *stend) {
size_t bufsize = *size;
//need to loop through all samples and identify our clock, look for the ST pattern
uint8_t fndClk[] = {8,16,32,40,50,64,128};
int tol = 0;
int i, j, skip, start, end, low, high, minClk, waveStart;
bool complete = false;
- int tmpbuff[bufsize / 64];
- int waveLen[bufsize / 64];
+ int tmpbuff[bufsize / 32]; //guess rf/32 clock, if click is smaller we will only have room for a fraction of the samples captured
+ int waveLen[bufsize / 32]; // if clock is larger then we waste memory in array size that is not needed...
size_t testsize = (bufsize < 512) ? bufsize : 512;
int phaseoff = 0;
high = low = 128;
memset(tmpbuff, 0, sizeof(tmpbuff));
+ memset(waveLen, 0, sizeof(waveLen));
+
if ( getHiLo(buffer, testsize, &high, &low, 80, 80) == -1 ) {
if (g_debugMode==2) prnt("DEBUG STT: just noise detected - quitting");
return false; //just noise
waveStart = i;
while ((buffer[i] > low) && (i < bufsize))
++i;
- if (j >= (bufsize/64)) {
+ if (j >= (bufsize/32)) {
break;
}
waveLen[j] = i - waveStart; //first high to first low
if (start < 0) {
if (g_debugMode==2) prnt("DEBUG STT: first STT not found - quitting");
return false;
+ } else {
+ if (g_debugMode==2) prnt("DEBUG STT: first STT found at: %d, j=%d",start, j);
}
if (waveLen[i+2] > clk*1+tol)
phaseoff = 0;
end = skip;
for (i += 3; i < j - 4; ++i) {
end += tmpbuff[i];
- if (tmpbuff[i] >= clk*1-tol && tmpbuff[i] <= (clk*2)+tol) { //1 to 2 clocks depending on 2 bits prior
+ if (tmpbuff[i] >= clk*1-tol && tmpbuff[i] <= (clk*2)+tol && waveLen[i] < clk+tol) { //1 to 2 clocks depending on 2 bits prior
if (tmpbuff[i+1] >= clk*2-tol && tmpbuff[i+1] <= clk*2+tol && waveLen[i+1] > clk*3/2-tol) { //2 clocks and wave size is 1 1/2
if (tmpbuff[i+2] >= (clk*3)/2-tol && tmpbuff[i+2] <= clk*2+tol && waveLen[i+2] > clk-tol) { //1 1/2 to 2 clocks and at least one full clock wave
if (tmpbuff[i+3] >= clk*1-tol && tmpbuff[i+3] <= clk*2+tol) { //1 to 2 clocks for end of ST + first bit
start = skip;
size_t datalen = end - start;
// check validity of datalen (should be even clock increments) - use a tolerance of up to 1/8th a clock
- if (datalen % clk > clk/8) {
+ if ( clk - (datalen % clk) <= clk/8) {
+ // padd the amount off - could be problematic... but shouldn't happen often
+ datalen += clk - (datalen % clk);
+ } else if ( (datalen % clk) <= clk/8 ) {
+ // padd the amount off - could be problematic... but shouldn't happen often
+ datalen -= datalen % clk;
+ } else {
if (g_debugMode==2) prnt("DEBUG STT: datalen not divisible by clk: %u %% %d = %d - quitting", datalen, clk, datalen % clk);
return false;
- } else {
- // padd the amount off - could be problematic... but shouldn't happen often
- datalen += datalen % clk;
}
// if datalen is less than one t55xx block - ERROR
if (datalen/clk < 8*4) {
return false;
}
size_t dataloc = start;
+ if (buffer[dataloc-(clk*4)-(clk/8)] <= low && buffer[dataloc] <= low && buffer[dataloc-(clk*4)] >= high) {
+ //we have low drift (and a low just before the ST and a low just after the ST) - compensate by backing up the start
+ for ( i=0; i <= (clk/8); ++i ) {
+ if ( buffer[dataloc - (clk*4) - i] <= low ) {
+ dataloc -= i;
+ break;
+ }
+ }
+ }
+
size_t newloc = 0;
i=0;
+ if (g_debugMode==2) prnt("DEBUG STT: Starting STT trim - start: %d, datalen: %d ",dataloc, datalen);
+ bool firstrun = true;
// warning - overwriting buffer given with raw wave data with ST removed...
while ( dataloc < bufsize-(clk/2) ) {
//compensate for long high at end of ST not being high due to signal loss... (and we cut out the start of wave high part)
for(i=0; i < clk/2-tol; ++i) {
buffer[dataloc+i] = high+5;
}
+ } //test for single sample outlier (high between two lows) in the case of very strong waves
+ if (buffer[dataloc] >= high && buffer[dataloc+2] <= low) {
+ buffer[dataloc] = buffer[dataloc+2];
+ buffer[dataloc+1] = buffer[dataloc+2];
+ }
+ if (firstrun) {
+ *stend = dataloc;
+ *ststart = dataloc-(clk*4);
+ firstrun=false;
}
for (i=0; i<datalen; ++i) {
if (i+newloc < bufsize) {
}
newloc += i;
//skip next ST - we just assume it will be there from now on...
+ if (g_debugMode==2) prnt("DEBUG STT: skipping STT at %d to %d", dataloc, dataloc+(clk*4));
dataloc += clk*4;
}
*size = newloc;
projects / proxmark3-svn / blobdiff