add lf PAC/Stanley tag read (#354)

[proxmark3-svn] / common / lfdemod.c

diff --git a/common/lfdemod.c b/common/lfdemod.c
index be9d361372cab66b8e9d98b402a39d37c86d6bb4..880e2c2b04ebfe20cd6d212f82d20837db9e5eb4 100644 (file)
--- a/common/lfdemod.c
+++ b/common/lfdemod.c
@@ -505,13 +505,14 @@ int DetectASKClock(uint8_t dest[], size_t size, int *clock, int maxErr) {
        return bestStart[best];
 }
 
-int DetectStrongNRZClk(uint8_t *dest, size_t size, int peak, int low){
+int DetectStrongNRZClk(uint8_t *dest, size_t size, int peak, int low, bool *strong) {
        //find shortest transition from high to low
+       *strong = false;
        size_t i = 0;
        size_t transition1 = 0;
        int lowestTransition = 255;
        bool lastWasHigh = false;
-
+       size_t transitionSampleCount = 0;
        //find first valid beginning of a high or low wave
        while ((dest[i] >= peak || dest[i] <= low) && (i < size))
                ++i;
@@ -527,10 +528,17 @@ int DetectStrongNRZClk(uint8_t *dest, size_t size, int peak, int low){
                        lastWasHigh = (dest[i] >= peak);
                        if (i-transition1 < lowestTransition) lowestTransition = i-transition1;
                        transition1 = i;
+               } else if (dest[i] < peak && dest[i] > low) {
+                       transitionSampleCount++;
                }
        }
        if (lowestTransition == 255) lowestTransition = 0;
        if (g_debugMode==2) prnt("DEBUG NRZ: detectstrongNRZclk smallest wave: %d",lowestTransition);
+       // if less than 10% of the samples were not peaks (or 90% were peaks) then we have a strong wave
+       if (transitionSampleCount / size < 10) {
+               *strong = true;
+               lowestTransition = getClosestClock(lowestTransition);
+       }
        return lowestTransition;
 }
 
@@ -550,7 +558,9 @@ int DetectNRZClock(uint8_t dest[], size_t size, int clock, size_t *clockStartIdx
        int peak, low;
        if (getHiLo(dest, loopCnt, &peak, &low, 90, 90) < 1) return 0;
 
-       int lowestTransition = DetectStrongNRZClk(dest, size-20, peak, low);
+       bool strong = false;
+       int lowestTransition = DetectStrongNRZClk(dest, size-20, peak, low, &strong);
+       if (strong) return lowestTransition;
        size_t ii;
        uint8_t clkCnt;
        uint8_t tol = 0;
@@ -1489,7 +1499,7 @@ size_t aggregate_bits(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t invert,
 
 //by marshmellow  (from holiman's base)
 // full fsk demod from GraphBuffer wave to decoded 1s and 0s (no mandemod)
-int fskdemod_ext(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t invert, uint8_t fchigh, uint8_t fclow, int *startIdx) {
+int fskdemod(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t invert, uint8_t fchigh, uint8_t fclow, int *startIdx) {
        if (justNoise(dest, size)) return 0;
        // FSK demodulator
        size = fsk_wave_demod(dest, size, fchigh, fclow, startIdx);
@@ -1497,11 +1507,6 @@ int fskdemod_ext(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t invert, uint
        return size;
 }
 
-int fskdemod(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t invert, uint8_t fchigh, uint8_t fclow) {
-       int startIdx=0;
-       return fskdemod_ext(dest, size, rfLen, invert, fchigh, fclow, &startIdx);
-}
-
 // by marshmellow
 // convert psk1 demod to psk2 demod
 // only transition waves are 1s
@@ -1628,12 +1633,12 @@ int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert) {
 
 // by marshmellow
 // FSK Demod then try to locate an AWID ID
-int AWIDdemodFSK(uint8_t *dest, size_t *size) {
+int AWIDdemodFSK(uint8_t *dest, size_t *size, int *waveStartIdx) {
        //make sure buffer has enough data
        if (*size < 96*50) return -1;
 
        // FSK demodulator
-       *size = fskdemod(dest, *size, 50, 1, 10, 8);  // fsk2a RF/50 
+       *size = fskdemod(dest, *size, 50, 1, 10, 8, waveStartIdx);  // fsk2a RF/50 
        if (*size < 96) return -3;  //did we get a good demod?
 
        uint8_t preamble[] = {0,0,0,0,0,0,0,1};
@@ -1715,10 +1720,10 @@ int gProxII_Demod(uint8_t BitStream[], size_t *size) {
 }
 
 // loop to get raw HID waveform then FSK demodulate the TAG ID from it
-int HIDdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo) {
+int HIDdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo, int *waveStartIdx) {
        size_t numStart=0, size2=*size, startIdx=0; 
-       // FSK demodulator
-       *size = fskdemod(dest, size2,50,1,10,8); //fsk2a
+       // FSK demodulator  fsk2a so invert and fc/10/8
+       *size = fskdemod(dest, size2, 50, 1, 10, 8, waveStartIdx);
        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};
@@ -1743,11 +1748,11 @@ int HIDdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32
        return (int)startIdx;
 }
 
-int IOdemodFSK(uint8_t *dest, size_t size) {
+int IOdemodFSK(uint8_t *dest, size_t size, int *waveStartIdx) {
        //make sure buffer has data
        if (size < 66*64) return -2;
-       // FSK demodulator
-       size = fskdemod(dest, size, 64, 1, 10, 8);  // FSK2a RF/64 
+       // FSK demodulator  RF/64, fsk2a so invert, and fc/10/8
+       size = fskdemod(dest, size, 64, 1, 10, 8, waveStartIdx); 
        if (size < 65) return -3;  //did we get a good demod?
        //Index map
        //0           10          20          30          40          50          60
@@ -1792,10 +1797,10 @@ int indala26decode(uint8_t *bitStream, size_t *size, uint8_t *invert) {
 }
 
 // loop to get raw paradox waveform then FSK demodulate the TAG ID from it
-int ParadoxdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo) {
+int ParadoxdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo, int *waveStartIdx) {
        size_t numStart=0, size2=*size, startIdx=0;
        // FSK demodulator
-       *size = fskdemod(dest, size2,50,1,10,8); //fsk2a
+       *size = fskdemod(dest, size2,50,1,10,8,waveStartIdx); //fsk2a
        if (*size < 96) return -2;
 
        // 00001111 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1
@@ -1835,12 +1840,12 @@ int PrescoDemod(uint8_t *dest, size_t *size) {
 
 // by marshmellow
 // FSK Demod then try to locate a Farpointe Data (pyramid) ID
-int PyramiddemodFSK(uint8_t *dest, size_t *size) {
+int PyramiddemodFSK(uint8_t *dest, size_t *size, int *waveStartIdx) {
        //make sure buffer has data
        if (*size < 128*50) return -5;
 
        // FSK demodulator
-       *size = fskdemod(dest, *size, 50, 1, 10, 8);  // fsk2a RF/50 
+       *size = fskdemod(dest, *size, 50, 1, 10, 8, waveStartIdx);  // 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};