//-----------------------------------------------------------------------------
#include <stdlib.h>
-#include <string.h>
#include "lfdemod.h"
+#include <string.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;
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 for Always 1's; 3 for Always 0'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
+ 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;
+ }
+ 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; 3 Always 0's), and binary Length (length to run)
+// Make sure *dest is long enough to store original sourceLen + #_of_parities_to_be_added
+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
+ switch (pType) {
+ case 3: dest[j++]=0; break; // marker bit which should be a 0
+ case 2: dest[j++]=1; break; // marker bit which should be a 1
+ default:
+ dest[j++] = parityTest(parityWd, pLen-1, pType) ^ 1;
+ break;
+ }
+ bitCnt += pLen;
+ parityWd = 0;
+ }
+ // if we got here then all the parities passed
+ //return ID start index and size
+ return bitCnt;
+}
+
+uint32_t bytebits_to_byte(uint8_t *src, size_t numbits)
+{
+ uint32_t num = 0;
+ for(int i = 0 ; i < numbits ; i++) {
+ num = (num << 1) | (*src);
+ src++;
+ }
+ 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;
+}
+
//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)
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;
} else if (waveHigh) {
BinStream[bitCnt++] = invert;
{
for(size_t i = 1; i<size; i++){
if (BitStream[i]-BitStream[i-1]>=30) //large jump up
- BitStream[i]=127;
+ BitStream[i]=255;
else if(BitStream[i]-BitStream[i-1]<=-20) //large jump down
- BitStream[i]=-127;
+ BitStream[i]=0;
}
return;
}
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);
uint8_t initLoopMax = 255;
if (initLoopMax > *size) initLoopMax = *size;
size_t errCnt = 0;
// if clean clipped waves detected run alternate demod
if (DetectCleanAskWave(BinStream, *size, high, low)) {
+ if (g_debugMode==2) prnt("DEBUG ASK: Clean Wave Detected - using clean wave demod");
errCnt = cleanAskRawDemod(BinStream, size, *clk, *invert, high, low);
if (askType) //askman
return manrawdecode(BinStream, size, 0);
else //askraw
return errCnt;
}
+ if (g_debugMode==2) prnt("DEBUG ASK: Weak Wave Detected - using weak wave demod");
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 = 1024;
+ size_t MaxBits = 3072; //max bits to collect
lastBit = start - *clk;
for (i = start; i < *size; ++i) {
BinStream[bitnum++] = *invert ^ 1;
} else if (i-lastBit >= *clk+tol) {
if (bitnum > 0) {
+ if (g_debugMode==2) prnt("DEBUG ASK: Modulation Error at: %u", i);
BinStream[bitnum++]=7;
errCnt++;
}
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)
//return start position
return (int) startIdx;
}
- return -5;
+ return -5; //spacer bits not found - not a valid gproxII
}
-//translate wave to 11111100000 (1 for each short wave 0 for each long wave)
+//translate wave to 11111100000 (1 for each short wave [higher freq] 0 for each long wave [lower freq])
size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow)
{
size_t last_transition = 0;
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
-
- 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++) {
+ // (could also be fc/5 && fc/7 for fsk1 = 4-9)
+ for(idx = 161; idx < size-20; idx++) {
// threshold current value
if (dest[idx] < threshold_value) dest[idx] = 0;
else dest[idx] = 1;
// Check for 0->1 transition
- if (dest[idx-1] < dest[idx]) { // 0 -> 1 transition
- if ((idx-last_transition)<(fclow-2)){ //0-5 = garbage noise
+ if (dest[idx-1] < dest[idx]) {
+ 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
+ } 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 )){
+ dest[numBits-1]=1;
+ }
dest[numBits++]=1;
- } else if ((idx-last_transition) > (fchigh+1) && !numBits) { //12 + and first bit = garbage
+
+ } else if (currSample > (fchigh) && !numBits) { //12 + and first bit = unusable 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 (or 4 then a 6 should be two 5's)
+ dest[numBits++]=1;
+ } else { //9+ = 10 sample waves (or 6+ = 7)
dest[numBits++]=0;
}
last_transition = idx;
}
//translate 11111100000 to 10
+//rfLen = clock, fchigh = larger field clock, fclow = smaller field clock
size_t aggregate_bits(uint8_t *dest, size_t size, uint8_t rfLen,
uint8_t invert, uint8_t fchigh, uint8_t fclow)
{
n++;
if (dest[idx]==lastval) continue;
+ //find out how many bits (n) we collected
//if lastval was 1, we have a 1->0 crossing
if (dest[idx-1]==1) {
- if (!numBits && n < rfLen/fclow) {
- n=0;
- lastval = dest[idx];
- continue;
- }
n = (n * fclow + rfLen/2) / rfLen;
} else {// 0->1 crossing
- //test first bitsample too small
- if (!numBits && n < rfLen/fchigh) {
- n=0;
- lastval = dest[idx];
- continue;
- }
n = (n * fchigh + rfLen/2) / rfLen;
}
if (n == 0) n = 1;
+ //add to our destination the bits we collected
memset(dest+numBits, dest[idx-1]^invert , n);
numBits += n;
n=0;
}
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)
return (int)startIdx;
}
-uint32_t bytebits_to_byte(uint8_t *src, size_t numbits)
-{
- uint32_t num = 0;
- for(int i = 0 ; i < numbits ; i++)
- {
- num = (num << 1) | (*src);
- src++;
- }
- 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;
}
// 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 for just drop it), 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--;
- // if parity fails then return 0
- if (pType != 2) {
- if (parityTest(parityWd, pLen, pType) == 0) return -1;
- }
- bitCnt+=(pLen-1);
- parityWd = 0;
- }
- // if we got here then all the parities passed
- //return ID start index and size
- return bitCnt;
+// 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;
+}
+
+// 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;
+
+ 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
+ //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 ISO11784demodBI(uint8_t *dest, size_t *size)
+int FDXBdemodBI(uint8_t *dest, size_t *size)
{
//make sure buffer has enough data
if (*size < 128) return -1;
}
// by marshmellow
-// FSK Demod then try to locate an Farpointe Data (pyramid) ID
+// FSK Demod then try to locate a Farpointe Data (pyramid) ID
int PyramiddemodFSK(uint8_t *dest, size_t *size)
{
//make sure buffer has data
// to detect a wave that has heavily clipped (clean) samples
uint8_t DetectCleanAskWave(uint8_t dest[], size_t size, uint8_t high, uint8_t low)
{
- uint16_t allPeaks=1;
+ bool allArePeaks = true;
uint16_t cntPeaks=0;
- size_t loopEnd = 512+60;
+ size_t loopEnd = 512+160;
if (loopEnd > size) loopEnd = size;
- for (size_t i=60; i<loopEnd; i++){
+ for (size_t i=160; i<loopEnd; i++){
if (dest[i]>low && dest[i]<high)
- allPeaks=0;
+ allArePeaks = false;
else
cntPeaks++;
}
- if (allPeaks == 0){
- if (cntPeaks > 300) return 1;
+ if (!allArePeaks){
+ if (cntPeaks > 300) return true;
}
- return allPeaks;
+ return allArePeaks;
}
-
// by marshmellow
// to help detect clocks on heavily clipped samples
// based on count of low to low
{
uint8_t fndClk[] = {8,16,32,40,50,64,128};
size_t startwave;
- size_t i = 0;
+ size_t i = 100;
size_t minClk = 255;
// get to first full low to prime loop and skip incomplete first pulse
while ((dest[i] < high) && (i < size))
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];
uint8_t clk[] = {255,8,16,32,40,50,64,100,128,255};
uint8_t clkEnd = 9;
uint8_t loopCnt = 255; //don't need to loop through entire array...
- if (size <= loopCnt) return -1; //not enough samples
-
+ if (size <= loopCnt+60) return -1; //not enough samples
+ size -= 60; //sometimes there is a strange end wave - filter out this....
//if we already have a valid clock
uint8_t clockFnd=0;
for (;i<clkEnd;++i)
if (!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;
}
}
}
-
uint8_t ii;
uint8_t clkCnt, tol = 0;
uint16_t bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000,1000};
}
//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 (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;
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]);
}
- //if (bestErr[best] > maxErr) return -1;
if (!clockFnd) *clock = clk[best];
return bestStart[best];
}
uint8_t clk[]={255,16,32,40,50,64,100,128,255}; //255 is not a valid clock
uint16_t loopCnt = 4096; //don't need to loop through entire array...
if (size == 0) return 0;
- if (size<loopCnt) loopCnt = size;
+ if (size<loopCnt) loopCnt = size-20;
//if we already have a valid clock quit
size_t i=1;
uint16_t peaksdet[]={0,0,0,0,0,0,0,0,0};
fc = countFC(dest, size, 0);
if (fc!=2 && fc!=4 && fc!=8) return -1;
- //PrintAndLog("DEBUG: FC: %d",fc);
+ if (g_debugMode==2) prnt("DEBUG PSK: FC: %d",fc);
//find first full wave
- for (i=0; i<loopCnt; i++){
+ for (i=160; i<loopCnt; i++){
if (dest[i] < dest[i+1] && dest[i+1] >= dest[i+2]){
if (waveStart == 0) {
waveStart = i+1;
- //PrintAndLog("DEBUG: waveStart: %d",waveStart);
+ //prnt("DEBUG: waveStart: %d",waveStart);
} else {
waveEnd = i+1;
- //PrintAndLog("DEBUG: waveEnd: %d",waveEnd);
+ //prnt("DEBUG: waveEnd: %d",waveEnd);
waveLenCnt = waveEnd-waveStart;
if (waveLenCnt > fc){
firstFullWave = waveStart;
}
}
}
- //PrintAndLog("DEBUG: firstFullWave: %d, waveLen: %d",firstFullWave,fullWaveLen);
+ 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--){
waveStart = 0;
errCnt=0;
peakcnt=0;
- //PrintAndLog("DEBUG: clk: %d, lastClkBit: %d",clk[clkCnt],lastClkBit);
+ 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
waveLenCnt = waveEnd-waveStart;
if (waveLenCnt > fc){
//if this wave is a phase shift
- //PrintAndLog("DEBUG: phase shift at: %d, len: %d, nextClk: %d, ii: %d, fc: %d",waveStart,waveLenCnt,lastClkBit+clk[clkCnt]-tol,ii+1,fc);
+ 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];
if (peaksdet[i] > peaksdet[best]) {
best = i;
}
- //PrintAndLog("DEBUG: Clk: %d, peaks: %d, errs: %d, bestClk: %d",clk[iii],peaksdet[iii],bestErr[iii],clk[best]);
+ 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;
+ }
+ }
+ 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)
uint8_t clk[]={8,16,32,40,50,64,100,128,255};
size_t loopCnt = 4096; //don't need to loop through entire array...
if (size == 0) return 0;
- if (size<loopCnt) loopCnt = size;
-
+ if (size<loopCnt) loopCnt = size-20;
//if we already have a valid clock quit
for (; i < 8; ++i)
if (clk[i] == clock) return clock;
int peak, low;
if (getHiLo(dest, loopCnt, &peak, &low, 75, 75) < 1) return 0;
- //PrintAndLog("DEBUG: peak: %d, low: %d",peak,low);
+ int lowestTransition = DetectStrongNRZClk(dest, size-20, peak, low);
size_t ii;
uint8_t clkCnt;
uint8_t tol = 0;
- uint16_t peakcnt=0;
- uint16_t peaksdet[]={0,0,0,0,0,0,0,0};
- uint16_t maxPeak=0;
+ uint16_t smplCnt = 0;
+ int16_t peakcnt = 0;
+ int16_t peaksdet[] = {0,0,0,0,0,0,0,0};
+ uint16_t maxPeak = 255;
+ bool firstpeak = false;
//test for large clipped waves
for (i=0; i<loopCnt; i++){
if (dest[i] >= peak || dest[i] <= low){
- peakcnt++;
+ if (!firstpeak) continue;
+ smplCnt++;
} else {
- if (peakcnt>0 && maxPeak < peakcnt){
- maxPeak = peakcnt;
+ firstpeak=true;
+ if (smplCnt > 6 ){
+ if (maxPeak > smplCnt){
+ maxPeak = smplCnt;
+ //prnt("maxPk: %d",maxPeak);
+ }
+ peakcnt++;
+ //prnt("maxPk: %d, smplCnt: %d, peakcnt: %d",maxPeak,smplCnt,peakcnt);
+ smplCnt=0;
}
- peakcnt=0;
}
}
+ bool errBitHigh = 0;
+ bool bitHigh = 0;
+ uint8_t ignoreCnt = 0;
+ uint8_t ignoreWindow = 4;
+ bool lastPeakHigh = 0;
+ int lastBit = 0;
peakcnt=0;
//test each valid clock from smallest to greatest to see which lines up
for(clkCnt=0; clkCnt < 8; ++clkCnt){
- //ignore clocks smaller than largest peak
- if (clk[clkCnt]<maxPeak) continue;
-
+ //ignore clocks smaller than smallest peak
+ if (clk[clkCnt] < maxPeak - (clk[clkCnt]/4)) continue;
//try lining up the peaks by moving starting point (try first 256)
- for (ii=0; ii< loopCnt; ++ii){
+ for (ii=20; ii < loopCnt; ++ii){
if ((dest[ii] >= peak) || (dest[ii] <= low)){
peakcnt=0;
- // now that we have the first one lined up test rest of wave array
- for (i=0; i < ((int)((size-ii-tol)/clk[clkCnt])-1); ++i){
- if (dest[ii+(i*clk[clkCnt])]>=peak || dest[ii+(i*clk[clkCnt])]<=low){
+ 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]) {
int iii=7;
uint8_t best=0;
for (iii=7; iii > 0; iii--){
- if (peaksdet[iii] > peaksdet[best]){
+ if ((peaksdet[iii] >= (peaksdet[best]-1)) && (peaksdet[iii] <= peaksdet[best]+1) && lowestTransition) {
+ if (clk[iii] > (lowestTransition - (clk[iii]/8)) && clk[iii] < (lowestTransition + (clk[iii]/8))) {
best = iii;
}
- //PrintAndLog("DEBUG: Clk: %d, peaks: %d, errs: %d, bestClk: %d",clk[iii],peaksdet[iii],bestErr[iii],clk[best]);
+ } else if (peaksdet[iii] > peaksdet[best]){
+ best = iii;
+ }
+ 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];
}
int indala26decode(uint8_t *bitStream, size_t *size, uint8_t *invert)
{
//26 bit 40134 format (don't know other formats)
- int i;
- int long_wait=29;//29 leading zeros in format
- int start;
- int first = 0;
- int first2 = 0;
- int bitCnt = 0;
- int ii;
- // Finding the start of a UID
- for (start = 0; start <= *size - 250; start++) {
- first = bitStream[start];
- for (i = start; i < start + long_wait; i++) {
- if (bitStream[i] != first) {
- break;
- }
- }
- if (i == (start + long_wait)) {
- break;
- }
- }
- if (start == *size - 250 + 1) {
- // did not find start sequence
- return -1;
- }
- // Inverting signal if needed
- if (first == 1) {
- for (i = start; i < *size; i++) {
- bitStream[i] = !bitStream[i];
- }
- *invert = 1;
- }else *invert=0;
-
- int iii;
- //found start once now test length by finding next one
- for (ii=start+29; ii <= *size - 250; ii++) {
- first2 = bitStream[ii];
- for (iii = ii; iii < ii + long_wait; iii++) {
- if (bitStream[iii] != first2) {
- break;
- }
- }
- if (iii == (ii + long_wait)) {
- break;
- }
- }
- if (ii== *size - 250 + 1){
- // did not find second start sequence
- return -2;
- }
- bitCnt=ii-start;
+ uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1};
+ uint8_t preamble_i[] = {1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0};
+ size_t startidx = 0;
+ if (!preambleSearch(bitStream, preamble, sizeof(preamble), size, &startidx)){
+ // if didn't find preamble try again inverting
+ if (!preambleSearch(bitStream, preamble_i, sizeof(preamble_i), size, &startidx)) return -1;
+ *invert ^= 1;
+ }
+ if (*size != 64 && *size != 224) return -2;
+ if (*invert==1)
+ for (size_t i = startidx; i < *size; i++)
+ bitStream[i] ^= 1;
- // Dumping UID
- i = start;
- for (ii = 0; ii < bitCnt; ii++) {
- bitStream[ii] = bitStream[i++];
- }
- *size=bitCnt;
- return 1;
+ return (int) startidx;
}
-// by marshmellow - demodulate NRZ wave (both similar enough)
+// by marshmellow - demodulate NRZ wave - requires a read with strong signal
// peaks invert bit (high=1 low=0) each clock cycle = 1 bit determined by last peak
-// there probably is a much simpler way to do this....
-int nrzRawDemod(uint8_t *dest, size_t *size, int *clk, int *invert, int maxErr)
-{
+int nrzRawDemod(uint8_t *dest, size_t *size, int *clk, int *invert){
if (justNoise(dest, *size)) return -1;
*clk = DetectNRZClock(dest, *size, *clk);
if (*clk==0) return -2;
size_t i, gLen = 4096;
- if (gLen>*size) gLen = *size;
+ if (gLen>*size) gLen = *size-20;
int high, low;
if (getHiLo(dest, gLen, &high, &low, 75, 75) < 1) return -3; //25% fuzz on high 25% fuzz on low
- int lastBit = 0; //set first clock check
- size_t iii = 0, bitnum = 0; //bitnum counter
- uint16_t errCnt = 0, MaxBits = 1000;
- size_t bestErrCnt = maxErr+1;
- size_t bestPeakCnt = 0, bestPeakStart = 0;
- uint8_t bestFirstPeakHigh=0, firstPeakHigh=0, curBit=0, bitHigh=0, errBitHigh=0;
- uint8_t tol = 1; //clock tolerance adjust - waves will be accepted as within the clock if they fall + or - this value + clock from last valid wave
- uint16_t peakCnt=0;
- uint8_t ignoreWindow=4;
- uint8_t ignoreCnt=ignoreWindow; //in case of noise near peak
- //loop to find first wave that works - align to clock
- for (iii=0; iii < gLen; ++iii){
- if ((dest[iii]>=high) || (dest[iii]<=low)){
- if (dest[iii]>=high) firstPeakHigh=1;
- else firstPeakHigh=0;
- lastBit=iii-*clk;
- peakCnt=0;
- errCnt=0;
- //loop through to see if this start location works
- for (i = iii; i < *size; ++i) {
- // if we are at a clock bit
- if ((i >= lastBit + *clk - tol) && (i <= lastBit + *clk + tol)) {
- //test high/low
- if (dest[i] >= high || dest[i] <= low) {
- bitHigh = 1;
- peakCnt++;
- errBitHigh = 0;
- ignoreCnt = ignoreWindow;
- lastBit += *clk;
- } else if (i == lastBit + *clk + tol) {
- lastBit += *clk;
- }
- //else if no bars found
- } else if (dest[i] < high && dest[i] > low){
- if (ignoreCnt==0){
- bitHigh=0;
- if (errBitHigh==1) errCnt++;
- errBitHigh=0;
- } else {
- ignoreCnt--;
- }
- } else if ((dest[i]>=high || dest[i]<=low) && (bitHigh==0)) {
- //error bar found no clock...
- errBitHigh=1;
- }
- if (((i-iii) / *clk)>=MaxBits) break;
- }
- //we got more than 64 good bits and not all errors
- if (((i-iii) / *clk) > 64 && (errCnt <= (maxErr))) {
- //possible good read
- if (!errCnt || peakCnt > bestPeakCnt){
- bestFirstPeakHigh=firstPeakHigh;
- bestErrCnt = errCnt;
- bestPeakCnt = peakCnt;
- bestPeakStart = iii;
- if (!errCnt) break; //great read - finish
- }
- }
- }
+
+ uint8_t bit=0;
+ //convert wave samples to 1's and 0's
+ for(i=20; i < *size-20; i++){
+ if (dest[i] >= high) bit = 1;
+ if (dest[i] <= low) bit = 0;
+ dest[i] = bit;
}
- //PrintAndLog("DEBUG: bestErrCnt: %d, maxErr: %d, bestStart: %d, bestPeakCnt: %d, bestPeakStart: %d",bestErrCnt,maxErr,bestStart,bestPeakCnt,bestPeakStart);
- if (bestErrCnt > maxErr) return bestErrCnt;
-
- //best run is good enough set to best run and set overwrite BinStream
- lastBit = bestPeakStart - *clk;
- memset(dest, bestFirstPeakHigh^1, bestPeakStart / *clk);
- bitnum += (bestPeakStart / *clk);
- for (i = bestPeakStart; i < *size; ++i) {
- // if expecting a clock bit
- if ((i >= lastBit + *clk - tol) && (i <= lastBit + *clk + tol)) {
- // test high/low
- if (dest[i] >= high || dest[i] <= low) {
- peakCnt++;
- bitHigh = 1;
- errBitHigh = 0;
- ignoreCnt = ignoreWindow;
- curBit = *invert;
- if (dest[i] >= high) curBit ^= 1;
- dest[bitnum++] = curBit;
- lastBit += *clk;
- //else no bars found in clock area
- } else if (i == lastBit + *clk + tol) {
- dest[bitnum++] = curBit;
- lastBit += *clk;
- }
- //else if no bars found
- } else if (dest[i] < high && dest[i] > low){
- if (ignoreCnt == 0){
- bitHigh = 0;
- if (errBitHigh == 1){
- dest[bitnum++] = 7;
- errCnt++;
- }
- errBitHigh=0;
- } else {
- ignoreCnt--;
- }
- } else if ((dest[i] >= high || dest[i] <= low) && (bitHigh == 0)) {
- //error bar found no clock...
- errBitHigh=1;
+ //now demod based on clock (rf/32 = 32 1's for one 1 bit, 32 0's for one 0 bit)
+ size_t lastBit = 0;
+ size_t numBits = 0;
+ for(i=21; i < *size-20; i++) {
+ //if transition detected or large number of same bits - store the passed bits
+ if (dest[i] != dest[i-1] || (i-lastBit) == (10 * *clk)) {
+ memset(dest+numBits, dest[i-1] ^ *invert, (i - lastBit + (*clk/4)) / *clk);
+ numBits += (i - lastBit + (*clk/4)) / *clk;
+ lastBit = i-1;
}
- if (bitnum >= MaxBits) break;
}
- *size = bitnum;
- return bestErrCnt;
+ *size = numBits;
+ return 0;
}
//by marshmellow
size_t i;
if (size == 0) return 0;
- uint8_t fcTol = (uint8_t)(0.5+(float)(fcHigh-fcLow)/2);
+ uint8_t fcTol = ((fcHigh*100 - fcLow*100)/2 + 50)/100; //(uint8_t)(0.5+(float)(fcHigh-fcLow)/2);
rfLensFnd=0;
fcCounter=0;
rfCounter=0;
firstBitFnd=0;
//PrintAndLog("DEBUG: fcTol: %d",fcTol);
- // prime i to first up transition
- for (i = 1; i < size-1; i++)
+ // prime i to first peak / up transition
+ for (i = 160; i < size-20; i++)
if (BitStream[i] > BitStream[i-1] && BitStream[i]>=BitStream[i+1])
break;
- for (; i < size-1; i++){
+ for (; i < size-20; i++){
fcCounter++;
rfCounter++;
//not the same size as the last wave - start of new bit sequence
if (firstBitFnd > 1){ //skip first wave change - probably not a complete bit
for (int ii=0; ii<15; ii++){
- if (rfLens[ii] == rfCounter){
+ if (rfLens[ii] >= (rfCounter-4) && rfLens[ii] <= (rfCounter+4)){
rfCnts[ii]++;
rfCounter = 0;
break;
uint8_t rfHighest=15, rfHighest2=15, rfHighest3=15;
for (i=0; i<15; i++){
- //PrintAndLog("DEBUG: RF %d, cnts %d",rfLens[i], rfCnts[i]);
//get highest 2 RF values (might need to get more values to compare or compare all?)
if (rfCnts[i]>rfCnts[rfHighest]){
rfHighest3=rfHighest2;
} else if(rfCnts[i]>rfCnts[rfHighest3]){
rfHighest3=i;
}
+ 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;
- //PrintAndLog("DEBUG: hightest: 1 %d, 2 %d, 3 %d",rfLens[rfHighest],rfLens[rfHighest2],rfLens[rfHighest3]);
+ if (g_debugMode==2) prnt("DEBUG FSK: most counted rf values: 1 %d, 2 %d, 3 %d",rfLens[rfHighest],rfLens[rfHighest2],rfLens[rfHighest3]);
// loop to find the highest clock that has a remainder less than the tolerance
// compare samples counted divided by
+ // 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>=0; ii--){
+ for (; ii>=2; ii--){
if (rfLens[rfHighest] % clk[ii] < tol1 || rfLens[rfHighest] % clk[ii] > clk[ii]-tol1){
if (rfLens[rfHighest2] % clk[ii] < tol1 || rfLens[rfHighest2] % clk[ii] > clk[ii]-tol1){
if (rfLens[rfHighest3] % clk[ii] < tol1 || rfLens[rfHighest3] % clk[ii] > clk[ii]-tol1){
+ if (g_debugMode==2) prnt("DEBUG FSK: clk %d divides into the 3 most rf values within tolerance",clk[ii]);
break;
}
}
//mainly used for FSK field clock detection
uint16_t countFC(uint8_t *BitStream, size_t size, uint8_t fskAdj)
{
- uint8_t fcLens[] = {0,0,0,0,0,0,0,0,0,0};
- uint16_t fcCnts[] = {0,0,0,0,0,0,0,0,0,0};
+ uint8_t fcLens[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
+ uint16_t fcCnts[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
uint8_t fcLensFnd = 0;
uint8_t lastFCcnt=0;
uint8_t fcCounter = 0;
if (size == 0) return 0;
// prime i to first up transition
- for (i = 1; i < size-1; i++)
+ for (i = 160; i < size-20; i++)
if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1])
break;
- for (; i < size-1; i++){
+ for (; i < size-20; i++){
if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1]){
// new up transition
fcCounter++;
lastFCcnt = fcCounter;
}
// find which fcLens to save it to:
- for (int ii=0; ii<10; ii++){
+ for (int ii=0; ii<15; ii++){
if (fcLens[ii]==fcCounter){
fcCnts[ii]++;
fcCounter=0;
break;
}
}
- if (fcCounter>0 && fcLensFnd<10){
+ if (fcCounter>0 && fcLensFnd<15){
//add new fc length
fcCnts[fcLensFnd]++;
fcLens[fcLensFnd++]=fcCounter;
}
}
- uint8_t best1=9, best2=9, best3=9;
+ uint8_t best1=14, best2=14, best3=14;
uint16_t maxCnt1=0;
// go through fclens and find which ones are bigest 2
- for (i=0; i<10; i++){
- // PrintAndLog("DEBUG: FC %d, Cnt %d, Errs %d",fcLens[i],fcCnts[i],errCnt);
+ for (i=0; i<15; i++){
// get the 3 best FC values
if (fcCnts[i]>maxCnt1) {
best3=best2;
} else if(fcCnts[i]>fcCnts[best3]){
best3=i;
}
+ 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];
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
uint16_t fcs = (((uint16_t)fcH)<<8) | fcL;
- // PrintAndLog("DEBUG: Best %d best2 %d best3 %d",fcLens[best1],fcLens[best2],fcLens[best3]);
if (fskAdj) return fcs;
return fcLens[best1];
}
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;
waveEnd = i+1;
//PrintAndLog("DEBUG: waveEnd: %d",waveEnd);
waveLenCnt = waveEnd-waveStart;
- if (waveLenCnt > fc && waveStart > fc){ //not first peak and is a large wave
+ if (waveLenCnt > fc && waveStart > fc && !(waveLenCnt > fc+2)){ //not first peak and is a large wave but not out of whack
lastAvgWaveVal = avgWaveVal/(waveLenCnt);
firstFullWave = waveStart;
fullWaveLen=waveLenCnt;
}
avgWaveVal += dest[i+2];
}
- //PrintAndLog("DEBUG: firstFullWave: %d, waveLen: %d",firstFullWave,fullWaveLen);
- lastClkBit = firstFullWave; //set start of wave as clock align
- //PrintAndLog("DEBUG: clk: %d, lastClkBit: %d", *clock, lastClkBit);
- waveStart = 0;
- size_t numBits=0;
- //set skipped bits
- memset(dest, curPhase^1, firstFullWave / *clock);
+ 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;
+ 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);
+ 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
*size = numBits;
return errCnt;
}
+
+//by marshmellow
+//attempt to identify a Sequence Terminator in ASK modulated raw wave
+bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) {
+ 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 clk = 0;
+ int tol = 0;
+ int i, j, skip, start, end, low, high, minClk, waveStart;
+ bool complete = false;
+ int tmpbuff[bufsize / 64];
+ int waveLen[bufsize / 64];
+ size_t testsize = (bufsize < 512) ? bufsize : 512;
+ int phaseoff = 0;
+ high = low = 128;
+ memset(tmpbuff, 0, sizeof(tmpbuff));
+
+ if ( getHiLo(buffer, testsize, &high, &low, 80, 80) == -1 ) {
+ if (g_debugMode==2) prnt("DEBUG STT: just noise detected - quitting");
+ return false; //just noise
+ }
+ i = 0;
+ j = 0;
+ minClk = 255;
+ // get to first full low to prime loop and skip incomplete first pulse
+ while ((buffer[i] < high) && (i < bufsize))
+ ++i;
+ while ((buffer[i] > low) && (i < bufsize))
+ ++i;
+ skip = i;
+
+ // populate tmpbuff buffer with pulse lengths
+ while (i < bufsize) {
+ // measure from low to low
+ while ((buffer[i] > low) && (i < bufsize))
+ ++i;
+ start= i;
+ while ((buffer[i] < high) && (i < bufsize))
+ ++i;
+ //first high point for this wave
+ waveStart = i;
+ while ((buffer[i] > low) && (i < bufsize))
+ ++i;
+ if (j >= (bufsize/64)) {
+ break;
+ }
+ waveLen[j] = i - waveStart; //first high to first low
+ tmpbuff[j++] = i - start;
+ if (i-start < minClk && i < bufsize) {
+ minClk = i - start;
+ }
+ }
+ // set clock - might be able to get this externally and remove this work...
+ if (!clk) {
+ for (uint8_t clkCnt = 0; clkCnt<7; clkCnt++) {
+ tol = fndClk[clkCnt]/8;
+ if (minClk >= fndClk[clkCnt]-tol && minClk <= fndClk[clkCnt]+1) {
+ clk=fndClk[clkCnt];
+ break;
+ }
+ }
+ // clock not found - ERROR
+ if (!clk) {
+ if (g_debugMode==2) prnt("DEBUG STT: clock not found - quitting");
+ return false;
+ }
+ } else tol = clk/8;
+
+ *foundclock = clk;
+
+ // look for Sequence Terminator - should be pulses of clk*(1 or 1.5), clk*2, clk*(1.5 or 2)
+ start = -1;
+ for (i = 0; i < j - 4; ++i) {
+ skip += tmpbuff[i];
+ 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 = i + 3;
+ break;
+ }
+ }
+ }
+ }
+ }
+ // first ST not found - ERROR
+ if (start < 0) {
+ if (g_debugMode==2) prnt("DEBUG STT: first STT not found - quitting");
+ return false;
+ }
+ if (waveLen[i+2] > clk*1+tol)
+ phaseoff = 0;
+ else
+ phaseoff = clk/2;
+
+ // skip over the remainder of ST
+ skip += clk*7/2; //3.5 clocks from tmpbuff[i] = end of st - also aligns for ending point
+
+ // now do it again to find the end
+ 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+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
+ complete = true;
+ break;
+ }
+ }
+ }
+ }
+ }
+ end -= phaseoff;
+ //didn't find second ST - ERROR
+ if (!complete) {
+ if (g_debugMode==2) prnt("DEBUG STT: second STT not found - quitting");
+ return false;
+ }
+ if (g_debugMode==2) prnt("DEBUG STT: start of data: %d end of data: %d, datalen: %d, clk: %d, bits: %d, phaseoff: %d", skip, end, end-skip, clk, (end-skip)/clk, phaseoff);
+ //now begin to trim out ST so we can use normal demod cmds
+ 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 (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) {
+ if (g_debugMode==2) prnt("DEBUG STT: datalen is less than 1 full t55xx block - quitting");
+ return false;
+ }
+ size_t dataloc = start;
+ size_t newloc = 0;
+ i=0;
+ // 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)
+ if (buffer[dataloc]<high && buffer[dataloc]>low && buffer[dataloc+3]<high && buffer[dataloc+3]>low) {
+ for(i=0; i < clk/2-tol; ++i) {
+ buffer[dataloc+i] = high+5;
+ }
+ }
+ for (i=0; i<datalen; ++i) {
+ if (i+newloc < bufsize) {
+ if (i+newloc < dataloc)
+ buffer[i+newloc] = buffer[dataloc];
+
+ dataloc++;
+ }
+ }
+ newloc += i;
+ //skip next ST - we just assume it will be there from now on...
+ dataloc += clk*4;
+ }
+ *size = newloc;
+ return true;
+}
projects / proxmark3-svn / blobdiff