#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
+ } 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 last 9 wave surrounded by 8 waves
+ dest[numBits-1]=1; //correct previous 9 wave surrounded by 8 waves
}
dest[numBits++]=1;
//if lastval was 1, we have a 1->0 crossing
if (dest[idx-1]==1) {
- if (!numBits) {
- if (n < rfLen/fclow) {
- n=0;
- lastval = dest[idx];
- continue;
- }
- n = (n * fclow + rfLen/4) / rfLen;
- } else {
- n = (n * fclow + rfLen/2) / rfLen;
- }
+ 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)
}
// 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
return (int)startIdx;
}
-/*
-void dummy(char *fmt, ...){}
-
-#ifndef ON_DEVICE
-#include "ui.h"
-#define prnt PrintAndLog
-#else
-
-#define prnt dummy
-#endif
-*/
// by marshmellow
// to detect a wave that has heavily clipped (clean) samples
uint8_t DetectCleanAskWave(uint8_t dest[], size_t size, uint8_t high, uint8_t low)
{
- uint16_t allPeaks=1;
+ bool allArePeaks = true;
uint16_t cntPeaks=0;
size_t loopEnd = 512+160;
if (loopEnd > size) loopEnd = size;
for (size_t i=160; i<loopEnd; i++){
if (dest[i]>low && dest[i]<high)
- 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
size_t i = 0;
size_t transition1 = 0;
int lowestTransition = 255;
- uint8_t lastWasHigh=0;
- //find first valid beginning of a high/low wave
- if (dest[i] >= peak) {
- for (; i < size; i++) {
- if (dest[i] <= low) break;
- }
- lastWasHigh=0;
- } else if (dest[i] <= low) {
- for (; i < size; i++) {
- if (dest[i] >= peak) break;
- }
- lastWasHigh=1;
- } else {
- for (; i < size; i++) {
- if (dest[i] >= peak || dest[i] <= low) {
- lastWasHigh = (dest[i] >= peak);
- break;
- }
- }
- }
+ 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;
transition1 = i;
}
}
+ //prnt("DEBUG: LowestTrs: %d",lowestTransition);
if (lowestTransition == 255) lowestTransition = 0;
return lowestTransition;
}
if (getHiLo(dest, loopCnt, &peak, &low, 75, 75) < 1) return 0;
int lowestTransition = DetectStrongNRZClk(dest, size-20, peak, low);
- //prnt("DEBUG: peak: %d, low: %d",peak,low);
size_t ii;
uint8_t clkCnt;
uint8_t tol = 0;
int16_t peakcnt = 0;
int16_t peaksdet[] = {0,0,0,0,0,0,0,0};
uint16_t maxPeak = 255;
- uint8_t firstpeak = 0;
+ bool firstpeak = false;
//test for large clipped waves
for (i=0; i<loopCnt; i++){
if (dest[i] >= peak || dest[i] <= low){
if (!firstpeak) continue;
smplCnt++;
} else {
- firstpeak=1;
+ firstpeak=true;
if (smplCnt > 6 ){
if (maxPeak > smplCnt){
maxPeak = smplCnt;
}
}
}
- uint8_t samePeak=0;
- uint8_t errBitHigh=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){
//try lining up the peaks by moving starting point (try first 256)
for (ii=20; ii < loopCnt; ++ii){
if ((dest[ii] >= peak) || (dest[ii] <= low)){
- peakcnt=0;
- uint8_t bitHigh =0;
- uint8_t ignoreCnt = 0;
- uint8_t ignoreWindow = 4;
- int lastBit = ii-clk[clkCnt];
+ 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 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 (samePeak) peakcnt--;
- bitHigh=1;
- peakcnt++;
- errBitHigh = 0;
+ //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];
- samePeak = 1;
} else if (i == lastBit + clk[clkCnt] + tol) {
lastBit += clk[clkCnt];
- samePeak = 0;
}
//else if not a clock bit and no peaks
} else if (dest[i] < peak && dest[i] > low){
- samePeak = 0;
if (ignoreCnt==0){
- bitHigh=0;
- if (errBitHigh==1) peakcnt--;
- errBitHigh=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==0)) {
+ } else if ((dest[i]>=peak || dest[i]<=low) && (!bitHigh)) {
//error bar found no clock...
- errBitHigh=1;
+ errBitHigh=true;
}
}
if(peakcnt>peaksdet[clkCnt]) {
int iii=7;
uint8_t best=0;
for (iii=7; iii > 0; iii--){
- if (peaksdet[iii] > peaksdet[best]){
- best = iii;
- } else if (peaksdet[iii] == peaksdet[best] && lowestTransition){
- if (clk[iii] > (lowestTransition - (clk[iii]/8)) && clk[iii] < (lowestTransition + (clk[iii]/8))){
+ 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;
}
//prnt("DEBUG: Clk: %d, peaks: %d, maxPeak: %d, bestClk: %d, lowestTrs: %d",clk[iii],peaksdet[iii],maxPeak, clk[best], lowestTransition);
}
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];
}
projects / proxmark3-svn / commitdiff