#include <stdlib.h>
#include <string.h>
#include "lfdemod.h"
+#include "common.h"
+
+/* //un_comment to allow debug print calls when used not on device
+void dummy(char *fmt, ...){}
+
+#ifndef ON_DEVICE
+#include "ui.h"
+#define prnt PrintAndLog
+#else
+
+#define prnt dummy
+#endif
+*/
+
uint8_t justNoise(uint8_t *BitStream, size_t size)
{
static const uint8_t THRESHOLD = 123;
// sync to first lo-hi transition, and threshold
// Need to threshold first sample
-
- if(dest[0] < threshold_value) dest[0] = 0;
+ // skip 160 samples to allow antenna/samples to settle
+ if(dest[160] < threshold_value) dest[0] = 0;
else dest[0] = 1;
size_t numBits = 0;
// count cycles between consecutive lo-hi transitions, there should be either 8 (fc/8)
// or 10 (fc/10) cycles but in practice due to noise etc we may end up with with anywhere
// between 7 to 11 cycles so fuzz it by treat anything <9 as 8 and anything else as 10
- for(idx = 1; idx < size; idx++) {
+ for(idx = 161; idx < size-20; idx++) {
// threshold current value
if (dest[idx] < threshold_value) dest[idx] = 0;
preLastSample = LastSample;
LastSample = currSample;
currSample = idx-last_transition;
- if (currSample < (fclow-2)){ //0-5 = garbage noise
+ if (currSample < (fclow-2)){ //0-5 = garbage noise (or 0-3)
//do nothing with extra garbage
- } 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
+ } else if (currSample < (fchigh-1)) { //6-8 = 8 sample waves or 3-6 = 5
+ if (LastSample > (fchigh-2) && (preLastSample < (fchigh-1) || preLastSample == 0 )){
+ dest[numBits-1]=1; //correct previous 9 wave surrounded by 8 waves
}
dest[numBits++]=1;
- } else if (currSample > (fchigh+1) && !numBits) { //12 + and first bit = garbage
+ } else if (currSample > (fchigh) && !numBits) { //12 + and first bit = garbage
//do nothing with beginning garbage
} else if (currSample == (fclow+1) && LastSample == (fclow-1)) { // had a 7 then a 9 should be two 8's
dest[numBits++]=1;
//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;
}
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;
}
return -5;
+}
+
+// by marshmellow
+// find viking preamble 0xF200 in already demoded data
+int VikingDemod_AM(uint8_t *dest, size_t *size) {
+ //make sure buffer has data
+ if (*size < 64*2) return -2;
+
+ size_t startIdx = 0;
+ uint8_t preamble[] = {1,1,1,1,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
+ uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
+ if (errChk == 0) return -4; //preamble not found
+ uint32_t checkCalc = bytebits_to_byte(dest+startIdx,8) ^ bytebits_to_byte(dest+startIdx+8,8) ^ bytebits_to_byte(dest+startIdx+16,8)
+ ^ bytebits_to_byte(dest+startIdx+24,8) ^ bytebits_to_byte(dest+startIdx+32,8) ^ bytebits_to_byte(dest+startIdx+40,8)
+ ^ bytebits_to_byte(dest+startIdx+48,8) ^ bytebits_to_byte(dest+startIdx+56,8);
+ if ( checkCalc != 0xA8 ) return -5;
+ if (*size != 64) return -6;
+ //return start position
+ return (int) startIdx;
}
// by marshmellow
}
// 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
+ //prnt("minClk: %d",minClk);
for (uint8_t clkCnt = 0; clkCnt<7; clkCnt++) {
if (minClk >= fndClk[clkCnt]-(fndClk[clkCnt]/8) && minClk <= fndClk[clkCnt]+1)
return fndClk[clkCnt];
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)
}
}
}
-
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);
+ //prnt("DEBUG: clk %d, err %d, ii %d, i %d",clk[clkCnt],errCnt,ii,i);
if(errCnt==0 && clkCnt<7) {
if (!clockFnd) *clock = clk[clkCnt];
return ii;
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);
+ //prnt("DEBUG: 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);
+ //prnt("DEBUG: firstFullWave: %d, waveLen: %d",firstFullWave,fullWaveLen);
//test each valid clock from greatest to smallest to see which lines up
for(clkCnt=7; clkCnt >= 1 ; clkCnt--){
waveStart = 0;
errCnt=0;
peakcnt=0;
- //PrintAndLog("DEBUG: clk: %d, lastClkBit: %d",clk[clkCnt],lastClkBit);
+ //prnt("DEBUG: clk: %d, lastClkBit: %d",clk[clkCnt],lastClkBit);
for (i = firstFullWave+fullWaveLen-1; i < loopCnt-2; i++){
//top edge of wave = start of new wave
waveLenCnt = waveEnd-waveStart;
if (waveLenCnt > fc){
//if this wave is a phase shift
- //PrintAndLog("DEBUG: phase shift at: %d, len: %d, nextClk: %d, ii: %d, fc: %d",waveStart,waveLenCnt,lastClkBit+clk[clkCnt]-tol,ii+1,fc);
+ //prnt("DEBUG: phase shift at: %d, len: %d, nextClk: %d, ii: %d, fc: %d",waveStart,waveLenCnt,lastClkBit+clk[clkCnt]-tol,ii+1,fc);
if (i+1 >= lastClkBit + clk[clkCnt] - tol){ //should be a clock bit
peakcnt++;
lastClkBit+=clk[clkCnt];
if (peaksdet[i] > peaksdet[best]) {
best = i;
}
- //PrintAndLog("DEBUG: Clk: %d, peaks: %d, errs: %d, bestClk: %d",clk[iii],peaksdet[iii],bestErr[iii],clk[best]);
+ //prnt("DEBUG: Clk: %d, peaks: %d, errs: %d, bestClk: %d",clk[iii],peaksdet[iii],bestErr[iii],clk[best]);
}
return clk[best];
}
+int DetectStrongNRZClk(uint8_t *dest, size_t size, int peak, int low){
+ //find shortest transition from high to low
+ size_t i = 0;
+ size_t transition1 = 0;
+ int lowestTransition = 255;
+ bool lastWasHigh = false;
+
+ //find first valid beginning of a high or low wave
+ while ((dest[i] >= peak || dest[i] <= low) && (i < size))
+ ++i;
+ while ((dest[i] < peak && dest[i] > low) && (i < size))
+ ++i;
+ lastWasHigh = (dest[i] >= peak);
+
+ if (i==size) return 0;
+ transition1 = i;
+
+ for (;i < size; i++) {
+ if ((dest[i] >= peak && !lastWasHigh) || (dest[i] <= low && lastWasHigh)) {
+ lastWasHigh = (dest[i] >= peak);
+ if (i-transition1 < lowestTransition) lowestTransition = i-transition1;
+ transition1 = i;
+ }
+ }
+ //prnt("DEBUG: LowestTrs: %d",lowestTransition);
+ if (lowestTransition == 255) lowestTransition = 0;
+ return lowestTransition;
+}
+
//by marshmellow
//detect nrz clock by reading #peaks vs no peaks(or errors)
int DetectNRZClock(uint8_t dest[], size_t size, int clock)
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){
- peakcnt++;
+ peakcnt = 0;
+ bitHigh = false;
+ ignoreCnt = 0;
+ lastBit = ii-clk[clkCnt];
+ //loop through to see if this start location works
+ for (i = ii; i < size-20; ++i) {
+ //if we are at a clock bit
+ if ((i >= lastBit + clk[clkCnt] - tol) && (i <= lastBit + clk[clkCnt] + tol)) {
+ //test high/low
+ if (dest[i] >= peak || dest[i] <= low) {
+ //if same peak don't count it
+ if ((dest[i] >= peak && !lastPeakHigh) || (dest[i] <= low && lastPeakHigh)) {
+ peakcnt++;
+ }
+ lastPeakHigh = (dest[i] >= peak);
+ bitHigh = true;
+ errBitHigh = false;
+ ignoreCnt = ignoreWindow;
+ lastBit += clk[clkCnt];
+ } else if (i == lastBit + clk[clkCnt] + tol) {
+ lastBit += clk[clkCnt];
+ }
+ //else if not a clock bit and no peaks
+ } else if (dest[i] < peak && dest[i] > low){
+ if (ignoreCnt==0){
+ bitHigh=false;
+ if (errBitHigh==true) peakcnt--;
+ errBitHigh=false;
+ } else {
+ ignoreCnt--;
+ }
+ // else if not a clock bit but we have a peak
+ } else if ((dest[i]>=peak || dest[i]<=low) && (!bitHigh)) {
+ //error bar found no clock...
+ errBitHigh=true;
}
}
if(peakcnt>peaksdet[clkCnt]) {
int iii=7;
uint8_t best=0;
for (iii=7; iii > 0; iii--){
- if (peaksdet[iii] > peaksdet[best]){
+ if ((peaksdet[iii] >= (peaksdet[best]-1)) && (peaksdet[iii] <= peaksdet[best]+1) && lowestTransition) {
+ if (clk[iii] > (lowestTransition - (clk[iii]/8)) && clk[iii] < (lowestTransition + (clk[iii]/8))) {
+ best = iii;
+ }
+ } else if (peaksdet[iii] > peaksdet[best]){
best = iii;
}
- //PrintAndLog("DEBUG: Clk: %d, peaks: %d, errs: %d, bestClk: %d",clk[iii],peaksdet[iii],bestErr[iii],clk[best]);
+ //prnt("DEBUG: Clk: %d, peaks: %d, maxPeak: %d, bestClk: %d, lowestTrs: %d",clk[iii],peaksdet[iii],maxPeak, clk[best], lowestTransition);
}
+
return clk[best];
}
int indala26decode(uint8_t *bitStream, size_t *size, uint8_t *invert)
{
//26 bit 40134 format (don't know other formats)
- int i;
- int long_wait=29;//29 leading zeros in format
- int start;
- int first = 0;
- int first2 = 0;
- int bitCnt = 0;
- int ii;
- // Finding the start of a UID
- for (start = 0; start <= *size - 250; start++) {
- first = bitStream[start];
- for (i = start; i < start + long_wait; i++) {
- if (bitStream[i] != first) {
- break;
- }
- }
- if (i == (start + long_wait)) {
- break;
- }
- }
- if (start == *size - 250 + 1) {
- // did not find start sequence
- return -1;
- }
- // Inverting signal if needed
- if (first == 1) {
- for (i = start; i < *size; i++) {
- bitStream[i] = !bitStream[i];
- }
- *invert = 1;
- }else *invert=0;
-
- int iii;
- //found start once now test length by finding next one
- for (ii=start+29; ii <= *size - 250; ii++) {
- first2 = bitStream[ii];
- for (iii = ii; iii < ii + long_wait; iii++) {
- if (bitStream[iii] != first2) {
- break;
- }
- }
- if (iii == (ii + long_wait)) {
- break;
- }
- }
- if (ii== *size - 250 + 1){
- // did not find second start sequence
- return -2;
- }
- bitCnt=ii-start;
+ uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1};
+ uint8_t preamble_i[] = {1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0};
+ size_t startidx = 0;
+ if (!preambleSearch(bitStream, preamble, sizeof(preamble), size, &startidx)){
+ // if didn't find preamble try again inverting
+ if (!preambleSearch(bitStream, preamble_i, sizeof(preamble_i), size, &startidx)) return -1;
+ *invert ^= 1;
+ }
+ if (*size != 64 && *size != 224) return -2;
+ if (*invert==1)
+ for (size_t i = startidx; i < *size; i++)
+ bitStream[i] ^= 1;
- // Dumping UID
- i = start;
- for (ii = 0; ii < bitCnt; ii++) {
- bitStream[ii] = bitStream[i++];
- }
- *size=bitCnt;
- return 1;
+ return (int) startidx;
}
-// by marshmellow - demodulate NRZ wave (both similar enough)
+// by marshmellow - demodulate NRZ wave
// peaks invert bit (high=1 low=0) each clock cycle = 1 bit determined by last peak
-// 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]);
+ //prnt("DEBUG: RF %d, cnts %d",rfLens[i], rfCnts[i]);
//get highest 2 RF values (might need to get more values to compare or compare all?)
if (rfCnts[i]>rfCnts[rfHighest]){
rfHighest3=rfHighest2;
// we could have mistakenly made a 9 a 10 instead of an 8 or visa versa so rfLens could be 1 FC off
uint8_t tol1 = fcHigh+1;
- //PrintAndLog("DEBUG: hightest: 1 %d, 2 %d, 3 %d",rfLens[rfHighest],rfLens[rfHighest2],rfLens[rfHighest3]);
+ //prnt("DEBUG: hightest: 1 %d, 2 %d, 3 %d",rfLens[rfHighest],rfLens[rfHighest2],rfLens[rfHighest3]);
// loop to find the highest clock that has a remainder less than the tolerance
// compare samples counted divided by
+ // 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){
//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++){
+ //prnt("DEBUG: FC %d, Cnt %d",fcLens[i],fcCnts[i]);
// get the 3 best FC values
if (fcCnts[i]>maxCnt1) {
best3=best2;
best3=i;
}
}
+ 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];
}
+ //prnt("DEBUG: dd %d > %d",(size-180)/fcH/3,fcCnts[best1]+fcCnts[best2]);
+ if ((size-180)/fcH/3 > fcCnts[best1]+fcCnts[best2]) return 0; //lots of waves not psk or fsk
// TODO: take top 3 answers and compare to known Field clocks to get top 2
uint16_t fcs = (((uint16_t)fcH)<<8) | fcL;
- // PrintAndLog("DEBUG: Best %d best2 %d best3 %d",fcLens[best1],fcLens[best2],fcLens[best3]);
+ //prnt("DEBUG: Best %d best2 %d best3 %d",fcLens[best1],fcLens[best2],fcLens[best3]);
if (fskAdj) return fcs;
return fcLens[best1];
}
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];
}
+ if (firstFullWave == 0) {
+ // no phase shift detected - could be all 1's or 0's - doesn't matter where we start
+ // so skip a little to ensure we are past any Start Signal
+ firstFullWave = 160;
+ memset(dest, curPhase, firstFullWave / *clock);
+ } else {
+ memset(dest, curPhase^1, firstFullWave / *clock);
+ }
+ //advance bits
+ numBits += (firstFullWave / *clock);
+ //set start of wave as clock align
+ lastClkBit = firstFullWave;
//PrintAndLog("DEBUG: firstFullWave: %d, waveLen: %d",firstFullWave,fullWaveLen);
- 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);
- numBits += (firstFullWave / *clock);
dest[numBits++] = curPhase; //set first read bit
for (i = firstFullWave + fullWaveLen - 1; i < *size-3; i++){
//top edge of wave = start of new wave
projects / proxmark3-svn / blobdiff