//-----------------------------------------------------------------------------
-// Copyright (C) 2014
+// Copyright (C) 2014
//
// This code is licensed to you under the terms of the GNU GPL, version 2 or,
// at your option, any later version. See the LICENSE.txt file for the text of
// the license.
//-----------------------------------------------------------------------------
-// Low frequency commands
+// Low frequency demod/decode commands
//-----------------------------------------------------------------------------
#include <stdlib.h>
#include <string.h>
#include "lfdemod.h"
+
+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;
+}
+
//by marshmellow
-//takes 1s and 0s and searches for EM410x format - output EM ID
-uint64_t Em410xDecode(uint8_t *BitStream,uint32_t BitLen)
+//get high and low with passed in fuzz factor. also return noise test = 1 for passed or 0 for only noise
+int getHiLo(uint8_t *BitStream, size_t size, int *high, int *low, uint8_t fuzzHi, uint8_t fuzzLo)
{
- //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
- int high=0, low=128;
- uint64_t lo=0; //hi=0,
-
- uint32_t i = 0;
- uint32_t initLoopMax = 65;
- if (initLoopMax>BitLen) initLoopMax=BitLen;
-
- for (;i < initLoopMax; ++i) //65 samples should be plenty to find high and low values
- {
- if (BitStream[i] > high)
- high = BitStream[i];
- else if (BitStream[i] < low)
- low = BitStream[i];
- }
- if (((high !=1)||(low !=0))){ //allow only 1s and 0s
- // PrintAndLog("no data found");
- return 0;
- }
- uint8_t parityTest=0;
- // 111111111 bit pattern represent start of frame
- uint8_t frame_marker_mask[] = {1,1,1,1,1,1,1,1,1};
- uint32_t idx = 0;
- uint32_t ii=0;
- uint8_t resetCnt = 0;
- while( (idx + 64) < BitLen) {
-restart:
- // search for a start of frame marker
- if ( memcmp(BitStream+idx, frame_marker_mask, sizeof(frame_marker_mask)) == 0)
- { // frame marker found
- idx+=9;//sizeof(frame_marker_mask);
- for (i=0; i<10;i++){
- for(ii=0; ii<5; ++ii){
- parityTest += BitStream[(i*5)+ii+idx];
- }
- if (parityTest== ((parityTest>>1)<<1)){
- parityTest=0;
- for (ii=0; ii<4;++ii){
- //hi = (hi<<1)|(lo>>31);
- lo=(lo<<1LL)|(BitStream[(i*5)+ii+idx]);
- }
- //PrintAndLog("DEBUG: EM parity passed parity val: %d, i:%d, ii:%d,idx:%d, Buffer: %d%d%d%d%d,lo: %d",parityTest,i,ii,idx,BitStream[idx+ii+(i*5)-5],BitStream[idx+ii+(i*5)-4],BitStream[idx+ii+(i*5)-3],BitStream[idx+ii+(i*5)-2],BitStream[idx+ii+(i*5)-1],lo);
- }else {//parity failed
- //PrintAndLog("DEBUG: EM parity failed parity val: %d, i:%d, ii:%d,idx:%d, Buffer: %d%d%d%d%d",parityTest,i,ii,idx,BitStream[idx+ii+(i*5)-5],BitStream[idx+ii+(i*5)-4],BitStream[idx+ii+(i*5)-3],BitStream[idx+ii+(i*5)-2],BitStream[idx+ii+(i*5)-1]);
- parityTest=0;
- idx-=8;
- if (resetCnt>5)return 0;
- resetCnt++;
- goto restart;//continue;
- }
- }
- //skip last 5 bit parity test for simplicity.
- return lo;
- }else{
- idx++;
- }
+ *high=0;
+ *low=255;
+ // get high and low thresholds
+ for (int i=0; i < size; i++){
+ if (BitStream[i] > *high) *high = BitStream[i];
+ if (BitStream[i] < *low) *low = BitStream[i];
+ }
+ if (*high < 123) return -1; // just noise
+ *high = (int)(((*high-128)*(((float)fuzzHi)/100))+128);
+ *low = (int)(((*low-128)*(((float)fuzzLo)/100))+128);
+ return 1;
+}
+
+// by marshmellow
+// pass bits to be tested in bits, length bits passed in bitLen, and parity type (even=0 | odd=1) in pType
+// returns 1 if passed
+uint8_t parityTest(uint32_t bits, uint8_t bitLen, uint8_t pType)
+{
+ uint8_t ans = 0;
+ for (uint8_t i = 0; i < bitLen; i++){
+ ans ^= ((bits >> i) & 1);
+ }
+ //PrintAndLog("DEBUG: ans: %d, ptype: %d",ans,pType);
+ return (ans == pType);
+}
+
+//by marshmellow
+//search for given preamble in given BitStream and return startIndex and length
+uint8_t preambleSearch(uint8_t *BitStream, uint8_t *preamble, size_t pLen, size_t *size, size_t *startIdx)
+{
+ uint8_t foundCnt=0;
+ for (int idx=0; idx < *size - pLen; idx++){
+ if (memcmp(BitStream+idx, preamble, pLen) == 0){
+ //first index found
+ foundCnt++;
+ if (foundCnt == 1){
+ *startIdx = idx;
+ }
+ if (foundCnt == 2){
+ *size = idx - *startIdx;
+ return 1;
+ }
}
+ }
+ return 0;
+}
+
+
+//by marshmellow
+//takes 1s and 0s and searches for EM410x format - output EM ID
+uint64_t Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx)
+{
+ //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
+ uint64_t lo=0;
+ uint32_t i = 0;
+ if (BitStream[1]>1){ //allow only 1s and 0s
+ // PrintAndLog("no data found");
return 0;
+ }
+ // 111111111 bit pattern represent start of frame
+ uint8_t preamble[] = {1,1,1,1,1,1,1,1,1};
+ uint32_t idx = 0;
+ uint32_t parityBits = 0;
+ uint8_t errChk = 0;
+ *startIdx = 0;
+ for (uint8_t extraBitChk=0; extraBitChk<5; extraBitChk++){
+ errChk = preambleSearch(BitStream+extraBitChk+*startIdx, preamble, sizeof(preamble), size, startIdx);
+ if (errChk == 0) return 0;
+ idx = *startIdx + 9;
+ for (i=0; i<10;i++){ //loop through 10 sets of 5 bits (50-10p = 40 bits)
+ parityBits = bytebits_to_byte(BitStream+(i*5)+idx,5);
+ //check even parity
+ if (parityTest(parityBits, 5, 0) == 0){
+ //parity failed try next bit (in the case of 1111111111) but last 9 = preamble
+ startIdx++;
+ errChk = 0;
+ break;
+ }
+ for (uint8_t ii=0; ii<4; ii++){
+ lo = (lo << 1LL) | (BitStream[(i*5)+ii+idx]);
+ }
+ }
+ if (errChk != 0) return lo;
+ //skip last 5 bit parity test for simplicity.
+ // *size = 64;
+ }
+ return 0;
}
//by marshmellow
//takes 2 arguments - clock and invert both as integers
-//attempts to demodulate ask while decoding manchester
+//attempts to demodulate ask while decoding manchester
//prints binary found and saves in graphbuffer for further commands
-int askmandemod(uint8_t * BinStream,uint32_t *BitLen,int *clk, int *invert)
+int askmandemod(uint8_t *BinStream, size_t *size, int *clk, int *invert)
{
- int i;
- int high = 0, low = 128;
- *clk=DetectASKClock(BinStream,(size_t)*BitLen,*clk); //clock default
-
- if (*clk<8) *clk =64;
- if (*clk<32) *clk=32;
- if (*invert != 0 && *invert != 1) *invert=0;
- uint32_t initLoopMax = 200;
- if (initLoopMax>*BitLen) initLoopMax=*BitLen;
- // Detect high and lows
- for (i = 0; i < initLoopMax; ++i) //200 samples should be enough to find high and low values
- {
- if (BinStream[i] > high)
- high = BinStream[i];
- else if (BinStream[i] < low)
- low = BinStream[i];
- }
- if ((high < 158) ){ //throw away static
- //PrintAndLog("no data found");
- return -2;
- }
- //25% fuzz in case highs and lows aren't clipped [marshmellow]
- high=(int)((high-128)*.75)+128;
- low= (int)((low-128)*.75)+128;
-
- //PrintAndLog("DEBUG - valid high: %d - valid low: %d",high,low);
- int lastBit = 0; //set first clock check
- uint32_t bitnum = 0; //output counter
- int 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
- int iii = 0;
- uint32_t gLen = *BitLen;
- if (gLen > 3000) gLen=3000;
- uint8_t errCnt =0;
- uint32_t bestStart = *BitLen;
- uint32_t bestErrCnt = (*BitLen/1000);
- uint32_t maxErr = (*BitLen/1000);
- //PrintAndLog("DEBUG - lastbit - %d",lastBit);
- //loop to find first wave that works
- for (iii=0; iii < gLen; ++iii){
- if ((BinStream[iii]>=high)||(BinStream[iii]<=low)){
- lastBit=iii-*clk;
- errCnt=0;
- //loop through to see if this start location works
- for (i = iii; i < *BitLen; ++i) {
- if ((BinStream[i] >= high) && ((i-lastBit)>(*clk-tol))){
- lastBit+=*clk;
- } else if ((BinStream[i] <= low) && ((i-lastBit)>(*clk-tol))){
- //low found and we are expecting a bar
- lastBit+=*clk;
- } else {
- //mid value found or no bar supposed to be here
- if ((i-lastBit)>(*clk+tol)){
- //should have hit a high or low based on clock!!
-
- //debug
- //PrintAndLog("DEBUG - no wave in expected area - location: %d, expected: %d-%d, lastBit: %d - resetting search",i,(lastBit+(clk-((int)(tol)))),(lastBit+(clk+((int)(tol)))),lastBit);
-
- errCnt++;
- lastBit+=*clk;//skip over until hit too many errors
- if (errCnt>(maxErr)) break; //allow 1 error for every 1000 samples else start over
- }
- }
- if ((i-iii) >(400 * *clk)) break; //got plenty of bits
- }
- //we got more than 64 good bits and not all errors
- if ((((i-iii)/ *clk) > (64+errCnt)) && (errCnt<maxErr)) {
- //possible good read
- if (errCnt==0){
- bestStart=iii;
- bestErrCnt=errCnt;
- break; //great read - finish
- }
- if (errCnt<bestErrCnt){ //set this as new best run
- bestErrCnt=errCnt;
- bestStart = iii;
- }
- }
- }
- }
- if (bestErrCnt<maxErr){
- //best run is good enough set to best run and set overwrite BinStream
- iii=bestStart;
- lastBit=bestStart-*clk;
- bitnum=0;
- for (i = iii; i < *BitLen; ++i) {
- if ((BinStream[i] >= high) && ((i-lastBit)>(*clk-tol))){
- lastBit+=*clk;
- BinStream[bitnum] = *invert;
- bitnum++;
- } else if ((BinStream[i] <= low) && ((i-lastBit)>(*clk-tol))){
- //low found and we are expecting a bar
- lastBit+=*clk;
- BinStream[bitnum] = 1-*invert;
- bitnum++;
- } else {
- //mid value found or no bar supposed to be here
- if ((i-lastBit)>(*clk+tol)){
- //should have hit a high or low based on clock!!
-
- //debug
- //PrintAndLog("DEBUG - no wave in expected area - location: %d, expected: %d-%d, lastBit: %d - resetting search",i,(lastBit+(clk-((int)(tol)))),(lastBit+(clk+((int)(tol)))),lastBit);
- if (bitnum > 0){
- BinStream[bitnum]=77;
- bitnum++;
- }
-
- lastBit+=*clk;//skip over error
- }
- }
- if (bitnum >=400) break;
- }
- *BitLen=bitnum;
- } else{
- *invert=bestStart;
- *clk=iii;
- return -1;
- }
- return bestErrCnt;
+ int i;
+ int clk2=*clk;
+ *clk=DetectASKClock(BinStream, *size, *clk); //clock default
+
+ // if autodetected too low then adjust //MAY NEED ADJUSTMENT
+ if (clk2==0 && *clk<8) *clk =64;
+ if (clk2==0 && *clk<32) *clk=32;
+ if (*invert != 0 && *invert != 1) *invert=0;
+ uint32_t initLoopMax = 200;
+ if (initLoopMax > *size) initLoopMax=*size;
+ // Detect high and lows
+ // 25% fuzz in case highs and lows aren't clipped [marshmellow]
+ int high, low, ans;
+ ans = getHiLo(BinStream, initLoopMax, &high, &low, 75, 75);
+ if (ans<1) return -2; //just noise
+
+ // PrintAndLog("DEBUG - valid high: %d - valid low: %d",high,low);
+ int lastBit = 0; //set first clock check
+ uint32_t bitnum = 0; //output counter
+ int 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
+ int iii = 0;
+ uint32_t gLen = *size;
+ if (gLen > 3000) gLen=3000;
+ uint8_t errCnt =0;
+ uint32_t bestStart = *size;
+ uint32_t bestErrCnt = (*size/1000);
+ uint32_t maxErr = (*size/1000);
+ // PrintAndLog("DEBUG - lastbit - %d",lastBit);
+ // loop to find first wave that works
+ for (iii=0; iii < gLen; ++iii){
+ if ((BinStream[iii] >= high) || (BinStream[iii] <= low)){
+ lastBit=iii-*clk;
+ errCnt=0;
+ // loop through to see if this start location works
+ for (i = iii; i < *size; ++i) {
+ if ((BinStream[i] >= high) && ((i-lastBit) > (*clk-tol))){
+ lastBit+=*clk;
+ } else if ((BinStream[i] <= low) && ((i-lastBit) > (*clk-tol))){
+ //low found and we are expecting a bar
+ lastBit+=*clk;
+ } else {
+ //mid value found or no bar supposed to be here
+ if ((i-lastBit)>(*clk+tol)){
+ //should have hit a high or low based on clock!!
+
+ //debug
+ //PrintAndLog("DEBUG - no wave in expected area - location: %d, expected: %d-%d, lastBit: %d - resetting search",i,(lastBit+(clk-((int)(tol)))),(lastBit+(clk+((int)(tol)))),lastBit);
+
+ errCnt++;
+ lastBit+=*clk;//skip over until hit too many errors
+ if (errCnt>(maxErr)) break; //allow 1 error for every 1000 samples else start over
+ }
+ }
+ if ((i-iii) >(400 * *clk)) break; //got plenty of bits
+ }
+ //we got more than 64 good bits and not all errors
+ if ((((i-iii)/ *clk) > (64+errCnt)) && (errCnt<maxErr)) {
+ //possible good read
+ if (errCnt==0){
+ bestStart=iii;
+ bestErrCnt=errCnt;
+ break; //great read - finish
+ }
+ if (errCnt<bestErrCnt){ //set this as new best run
+ bestErrCnt=errCnt;
+ bestStart = iii;
+ }
+ }
+ }
+ }
+ if (bestErrCnt<maxErr){
+ //best run is good enough set to best run and set overwrite BinStream
+ iii=bestStart;
+ lastBit = bestStart - *clk;
+ bitnum=0;
+ for (i = iii; i < *size; ++i) {
+ if ((BinStream[i] >= high) && ((i-lastBit) > (*clk-tol))){
+ lastBit += *clk;
+ BinStream[bitnum] = *invert;
+ bitnum++;
+ } else if ((BinStream[i] <= low) && ((i-lastBit) > (*clk-tol))){
+ //low found and we are expecting a bar
+ lastBit+=*clk;
+ BinStream[bitnum] = 1-*invert;
+ bitnum++;
+ } else {
+ //mid value found or no bar supposed to be here
+ if ((i-lastBit)>(*clk+tol)){
+ //should have hit a high or low based on clock!!
+
+ //debug
+ //PrintAndLog("DEBUG - no wave in expected area - location: %d, expected: %d-%d, lastBit: %d - resetting search",i,(lastBit+(clk-((int)(tol)))),(lastBit+(clk+((int)(tol)))),lastBit);
+ if (bitnum > 0){
+ BinStream[bitnum]=77;
+ bitnum++;
+ }
+
+ lastBit+=*clk;//skip over error
+ }
+ }
+ if (bitnum >=400) break;
+ }
+ *size=bitnum;
+ } else{
+ *invert=bestStart;
+ *clk=iii;
+ return -1;
+ }
+ return bestErrCnt;
+}
+
+//by marshmellow
+//encode binary data into binary manchester
+int ManchesterEncode(uint8_t *BitStream, size_t size)
+{
+ size_t modIdx=20000, i=0;
+ if (size>modIdx) return -1;
+ for (size_t idx=0; idx < size; idx++){
+ BitStream[idx+modIdx++] = BitStream[idx];
+ BitStream[idx+modIdx++] = BitStream[idx]^1;
+ }
+ for (; i<(size*2); i++){
+ BitStream[i] = BitStream[i+20000];
+ }
+ return i;
}
//by marshmellow
//take 10 and 01 and manchester decode
//run through 2 times and take least errCnt
-int manrawdecode(uint8_t * BitStream, int *bitLen)
+int manrawdecode(uint8_t * BitStream, size_t *size)
{
- int bitnum=0;
- int errCnt =0;
- int i=1;
- int bestErr = 1000;
- int bestRun = 0;
- int ii=1;
- for (ii=1;ii<3;++ii){
- i=1;
- for (i=i+ii;i<*bitLen-2;i+=2){
- if(BitStream[i]==1 && (BitStream[i+1]==0)){
- } else if((BitStream[i]==0)&& BitStream[i+1]==1){
- } else {
- errCnt++;
- }
- if(bitnum>300) break;
- }
- if (bestErr>errCnt){
- bestErr=errCnt;
- bestRun=ii;
- }
- errCnt=0;
- }
- errCnt=bestErr;
- if (errCnt<20){
- ii=bestRun;
- i=1;
- for (i=i+ii;i<*bitLen-2;i+=2){
- if(BitStream[i]==1 && (BitStream[i+1]==0)){
- BitStream[bitnum++]=0;
- } else if((BitStream[i]==0)&& BitStream[i+1]==1){
- BitStream[bitnum++]=1;
- } else {
- BitStream[bitnum++]=77;
- //errCnt++;
- }
- if(bitnum>300) break;
- }
- *bitLen=bitnum;
- }
- return errCnt;
+ int bitnum=0;
+ int errCnt =0;
+ int i=1;
+ int bestErr = 1000;
+ int bestRun = 0;
+ int ii=1;
+ for (ii=1;ii<3;++ii){
+ i=1;
+ for (i=i+ii;i<*size-2;i+=2){
+ if(BitStream[i]==1 && (BitStream[i+1]==0)){
+ } else if((BitStream[i]==0)&& BitStream[i+1]==1){
+ } else {
+ errCnt++;
+ }
+ if(bitnum>300) break;
+ }
+ if (bestErr>errCnt){
+ bestErr=errCnt;
+ bestRun=ii;
+ }
+ errCnt=0;
+ }
+ errCnt=bestErr;
+ if (errCnt<20){
+ ii=bestRun;
+ i=1;
+ for (i=i+ii;i < *size-2;i+=2){
+ if(BitStream[i] == 1 && (BitStream[i+1] == 0)){
+ BitStream[bitnum++]=0;
+ } else if((BitStream[i] == 0) && BitStream[i+1] == 1){
+ BitStream[bitnum++]=1;
+ } else {
+ BitStream[bitnum++]=77;
+ //errCnt++;
+ }
+ if(bitnum>300) break;
+ }
+ *size=bitnum;
+ }
+ return errCnt;
}
-
//by marshmellow
//take 01 or 10 = 0 and 11 or 00 = 1
-int BiphaseRawDecode(uint8_t * BitStream, int *bitLen, int offset)
+int BiphaseRawDecode(uint8_t *BitStream, size_t *size, int offset, int invert)
{
- uint8_t bitnum=0;
- uint32_t errCnt =0;
- uint32_t i=1;
- i=offset;
- for (;i<*bitLen-2;i+=2){
- if((BitStream[i]==1 && BitStream[i+1]==0)||(BitStream[i]==0 && BitStream[i+1]==1)){
- BitStream[bitnum++]=1;
- } else if((BitStream[i]==0 && BitStream[i+1]==0)||(BitStream[i]==1 && BitStream[i+1]==1)){
- BitStream[bitnum++]=0;
- } else {
- BitStream[bitnum++]=77;
- errCnt++;
- }
- if(bitnum>250) break;
- }
- *bitLen=bitnum;
- return errCnt;
+ uint8_t bitnum=0;
+ uint32_t errCnt =0;
+ uint32_t i;
+ i=offset;
+ for (;i<*size-2; i+=2){
+ if((BitStream[i]==1 && BitStream[i+1]==0) || (BitStream[i]==0 && BitStream[i+1]==1)){
+ BitStream[bitnum++]=1^invert;
+ } else if((BitStream[i]==0 && BitStream[i+1]==0) || (BitStream[i]==1 && BitStream[i+1]==1)){
+ BitStream[bitnum++]=invert;
+ } else {
+ BitStream[bitnum++]=77;
+ errCnt++;
+ }
+ if(bitnum>250) break;
+ }
+ *size=bitnum;
+ return errCnt;
}
//by marshmellow
//takes 2 arguments - clock and invert both as integers
//attempts to demodulate ask only
//prints binary found and saves in graphbuffer for further commands
-int askrawdemod(uint8_t *BinStream, int *bitLen,int *clk, int *invert)
+int askrawdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert)
{
- uint32_t i;
- // int invert=0; //invert default
- int high = 0, low = 128;
- *clk=DetectASKClock(BinStream,*bitLen,*clk); //clock default
- uint8_t BitStream[502] = {0};
-
- if (*clk<8) *clk =64;
- if (*clk<32) *clk=32;
- if (*invert != 0 && *invert != 1) *invert =0;
- uint32_t initLoopMax = 200;
- if (initLoopMax>*bitLen) initLoopMax=*bitLen;
- // Detect high and lows
- for (i = 0; i < initLoopMax; ++i) //200 samples should be plenty to find high and low values
- {
- if (BinStream[i] > high)
- high = BinStream[i];
- else if (BinStream[i] < low)
- low = BinStream[i];
- }
- if ((high < 158)){ //throw away static
- // PrintAndLog("no data found");
- return -2;
- }
- //25% fuzz in case highs and lows aren't clipped [marshmellow]
- high=(int)((high-128)*.75)+128;
- low= (int)((low-128)*.75)+128;
-
- //PrintAndLog("DEBUG - valid high: %d - valid low: %d",high,low);
- int lastBit = 0; //set first clock check
- uint32_t bitnum = 0; //output counter
- 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
- uint32_t iii = 0;
- uint32_t gLen = *bitLen;
- if (gLen > 500) gLen=500;
- uint8_t errCnt =0;
- uint32_t bestStart = *bitLen;
- uint32_t bestErrCnt = (*bitLen/1000);
- uint8_t midBit=0;
- //PrintAndLog("DEBUG - lastbit - %d",lastBit);
- //loop to find first wave that works
- for (iii=0; iii < gLen; ++iii){
- if ((BinStream[iii]>=high)||(BinStream[iii]<=low)){
- lastBit=iii-*clk;
- //loop through to see if this start location works
- for (i = iii; i < *bitLen; ++i) {
- if ((BinStream[i] >= high) && ((i-lastBit)>(*clk-tol))){
- lastBit+=*clk;
- BitStream[bitnum] = *invert;
- bitnum++;
- midBit=0;
- } else if ((BinStream[i] <= low) && ((i-lastBit)>(*clk-tol))){
- //low found and we are expecting a bar
- lastBit+=*clk;
- BitStream[bitnum] = 1-*invert;
- bitnum++;
- midBit=0;
- } else if ((BinStream[i]<=low) && (midBit==0) && ((i-lastBit)>((*clk/2)-tol))){
- //mid bar?
- midBit=1;
- BitStream[bitnum]= 1-*invert;
- bitnum++;
- } else if ((BinStream[i]>=high)&&(midBit==0) && ((i-lastBit)>((*clk/2)-tol))){
- //mid bar?
- midBit=1;
- BitStream[bitnum]= *invert;
- bitnum++;
- } else if ((i-lastBit)>((*clk/2)+tol)&&(midBit==0)){
- //no mid bar found
- midBit=1;
- BitStream[bitnum]= BitStream[bitnum-1];
- bitnum++;
- } else {
- //mid value found or no bar supposed to be here
-
- if ((i-lastBit)>(*clk+tol)){
- //should have hit a high or low based on clock!!
- //debug
- //PrintAndLog("DEBUG - no wave in expected area - location: %d, expected: %d-%d, lastBit: %d - resetting search",i,(lastBit+(clk-((int)(tol)))),(lastBit+(clk+((int)(tol)))),lastBit);
- if (bitnum > 0){
- BitStream[bitnum]=77;
- bitnum++;
- }
-
-
- errCnt++;
- lastBit+=*clk;//skip over until hit too many errors
- if (errCnt>((*bitLen/1000))){ //allow 1 error for every 1000 samples else start over
- errCnt=0;
- bitnum=0;//start over
- break;
- }
- }
- }
- if (bitnum>500) break;
- }
- //we got more than 64 good bits and not all errors
- if ((bitnum > (64+errCnt)) && (errCnt<(*bitLen/1000))) {
- //possible good read
- if (errCnt==0) break; //great read - finish
- if (bestStart == iii) break; //if current run == bestErrCnt run (after exhausted testing) then finish
- if (errCnt<bestErrCnt){ //set this as new best run
- bestErrCnt=errCnt;
- bestStart = iii;
- }
- }
- }
- if (iii>=gLen){ //exhausted test
- //if there was a ok test go back to that one and re-run the best run (then dump after that run)
- if (bestErrCnt < (*bitLen/1000)) iii=bestStart;
- }
- }
- if (bitnum>16){
+ uint32_t i;
+ // int invert=0; //invert default
+ int clk2 = *clk;
+ *clk=DetectASKClock(BinStream, *size, *clk); //clock default
+ //uint8_t BitStream[502] = {0};
- // PrintAndLog("Data start pos:%d, lastBit:%d, stop pos:%d, numBits:%d",iii,lastBit,i,bitnum);
- //move BitStream back to BinStream
- // ClearGraph(0);
- for (i=0; i < bitnum; ++i){
- BinStream[i]=BitStream[i];
- }
- *bitLen=bitnum;
- // RepaintGraphWindow();
- //output
- // if (errCnt>0){
- // PrintAndLog("# Errors during Demoding (shown as 77 in bit stream): %d",errCnt);
- // }
- // PrintAndLog("ASK decoded bitstream:");
- // Now output the bitstream to the scrollback by line of 16 bits
- // printBitStream2(BitStream,bitnum);
- //int errCnt=0;
- //errCnt=manrawdemod(BitStream,bitnum);
-
- // Em410xDecode(Cmd);
- } else return -1;
- return errCnt;
+ //HACK: if clock not detected correctly - default
+ if (clk2==0 && *clk<8) *clk =64;
+ if (clk2==0 && *clk<32 && clk2==0) *clk=32;
+ if (*invert != 0 && *invert != 1) *invert =0;
+ uint32_t initLoopMax = 200;
+ if (initLoopMax > *size) initLoopMax=*size;
+ // Detect high and lows
+ //25% fuzz in case highs and lows aren't clipped [marshmellow]
+ int high, low, ans;
+ ans = getHiLo(BinStream, initLoopMax, &high, &low, 75, 75);
+ if (ans<1) return -2; //just noise
+
+ //PrintAndLog("DEBUG - valid high: %d - valid low: %d",high,low);
+ int lastBit = 0; //set first clock check
+ uint32_t bitnum = 0; //output counter
+ 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
+ uint32_t iii = 0;
+ uint32_t gLen = *size;
+ if (gLen > 500) gLen=500;
+ uint8_t errCnt =0;
+ uint32_t bestStart = *size;
+ uint32_t bestErrCnt = (*size/1000);
+ uint32_t maxErr = bestErrCnt;
+ uint8_t midBit=0;
+ //PrintAndLog("DEBUG - lastbit - %d",lastBit);
+ //loop to find first wave that works
+ for (iii=0; iii < gLen; ++iii){
+ if ((BinStream[iii]>=high) || (BinStream[iii]<=low)){
+ lastBit=iii-*clk;
+ //loop through to see if this start location works
+ for (i = iii; i < *size; ++i) {
+ if ((BinStream[i] >= high) && ((i-lastBit)>(*clk-tol))){
+ lastBit+=*clk;
+ midBit=0;
+ } else if ((BinStream[i] <= low) && ((i-lastBit)>(*clk-tol))){
+ //low found and we are expecting a bar
+ lastBit+=*clk;
+ midBit=0;
+ } else if ((BinStream[i]<=low) && (midBit==0) && ((i-lastBit)>((*clk/2)-tol))){
+ //mid bar?
+ midBit=1;
+ } else if ((BinStream[i]>=high) && (midBit==0) && ((i-lastBit)>((*clk/2)-tol))){
+ //mid bar?
+ midBit=1;
+ } else if ((i-lastBit)>((*clk/2)+tol) && (midBit==0)){
+ //no mid bar found
+ midBit=1;
+ } else {
+ //mid value found or no bar supposed to be here
+
+ if ((i-lastBit)>(*clk+tol)){
+ //should have hit a high or low based on clock!!
+ //debug
+ //PrintAndLog("DEBUG - no wave in expected area - location: %d, expected: %d-%d, lastBit: %d - resetting search",i,(lastBit+(clk-((int)(tol)))),(lastBit+(clk+((int)(tol)))),lastBit);
+
+ errCnt++;
+ lastBit+=*clk;//skip over until hit too many errors
+ if (errCnt > ((*size/1000))){ //allow 1 error for every 1000 samples else start over
+ errCnt=0;
+ break;
+ }
+ }
+ }
+ if ((i-iii)>(500 * *clk)) break; //got enough bits
+ }
+ //we got more than 64 good bits and not all errors
+ if ((((i-iii)/ *clk) > (64+errCnt)) && (errCnt<(*size/1000))) {
+ //possible good read
+ if (errCnt==0){
+ bestStart=iii;
+ bestErrCnt=errCnt;
+ break; //great read - finish
+ }
+ if (errCnt<bestErrCnt){ //set this as new best run
+ bestErrCnt=errCnt;
+ bestStart = iii;
+ }
+ }
+ }
+ }
+ if (bestErrCnt<maxErr){
+ //best run is good enough - set to best run and overwrite BinStream
+ iii=bestStart;
+ lastBit = bestStart - *clk;
+ bitnum=0;
+ for (i = iii; i < *size; ++i) {
+ if ((BinStream[i] >= high) && ((i-lastBit) > (*clk-tol))){
+ lastBit += *clk;
+ BinStream[bitnum] = *invert;
+ bitnum++;
+ midBit=0;
+ } else if ((BinStream[i] <= low) && ((i-lastBit) > (*clk-tol))){
+ //low found and we are expecting a bar
+ lastBit+=*clk;
+ BinStream[bitnum] = 1-*invert;
+ bitnum++;
+ midBit=0;
+ } else if ((BinStream[i]<=low) && (midBit==0) && ((i-lastBit)>((*clk/2)-tol))){
+ //mid bar?
+ midBit=1;
+ BinStream[bitnum] = 1 - *invert;
+ bitnum++;
+ } else if ((BinStream[i]>=high) && (midBit==0) && ((i-lastBit)>((*clk/2)-tol))){
+ //mid bar?
+ midBit=1;
+ BinStream[bitnum] = *invert;
+ bitnum++;
+ } else if ((i-lastBit)>((*clk/2)+tol) && (midBit==0)){
+ //no mid bar found
+ midBit=1;
+ if (bitnum!=0) BinStream[bitnum] = BinStream[bitnum-1];
+ bitnum++;
+
+ } else {
+ //mid value found or no bar supposed to be here
+ if ((i-lastBit)>(*clk+tol)){
+ //should have hit a high or low based on clock!!
+
+ //debug
+ //PrintAndLog("DEBUG - no wave in expected area - location: %d, expected: %d-%d, lastBit: %d - resetting search",i,(lastBit+(clk-((int)(tol)))),(lastBit+(clk+((int)(tol)))),lastBit);
+ if (bitnum > 0){
+ BinStream[bitnum]=77;
+ bitnum++;
+ }
+
+ lastBit+=*clk;//skip over error
+ }
+ }
+ if (bitnum >=400) break;
+ }
+ *size=bitnum;
+ } else{
+ *invert=bestStart;
+ *clk=iii;
+ return -1;
+ }
+ return bestErrCnt;
}
-//translate wave to 11111100000 (1 for each short wave 0 for each long wave)
+//translate wave to 11111100000 (1 for each short wave 0 for each long wave)
size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow)
{
- uint32_t last_transition = 0;
- uint32_t idx = 1;
- uint32_t maxVal=0;
- if (fchigh==0) fchigh=10;
- if (fclow==0) fclow=8;
- // we do care about the actual theshold value as sometimes near the center of the
- // wave we may get static that changes direction of wave for one value
- // if our value is too low it might affect the read. and if our tag or
- // antenna is weak a setting too high might not see anything. [marshmellow]
- if (size<100) return 0;
- for(idx=1; idx<100; idx++){
- if(maxVal<dest[idx]) maxVal = dest[idx];
- }
- // set close to the top of the wave threshold with 25% margin for error
- // less likely to get a false transition up there.
- // (but have to be careful not to go too high and miss some short waves)
- uint8_t threshold_value = (uint8_t)(((maxVal-128)*.75)+128);
- // idx=1;
- //uint8_t threshold_value = 127;
-
- // sync to first lo-hi transition, and threshold
-
- // Need to threshold first sample
-
- if(dest[0] < 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++) {
- // 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
- //do nothing with extra garbage
- } else if ((idx-last_transition) < (fchigh-1)) { //6-8 = 8 waves
- dest[numBits]=1;
- } else { //9+ = 10 waves
- dest[numBits]=0;
- }
- last_transition = idx;
- numBits++;
- }
- }
- return numBits; //Actually, it returns the number of bytes, but each byte represents a bit: 1 or 0
+ uint32_t last_transition = 0;
+ uint32_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
+ uint8_t threshold_value = 123;
+
+ // sync to first lo-hi transition, and threshold
+
+ // Need to threshold first sample
+
+ if(dest[0] < 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++) {
+ // 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
+ //do nothing with extra garbage
+ } else if ((idx-last_transition) < (fchigh-1)) { //6-8 = 8 waves
+ dest[numBits]=1;
+ } else { //9+ = 10 waves
+ dest[numBits]=0;
+ }
+ last_transition = idx;
+ numBits++;
+ }
+ }
+ return numBits; //Actually, it returns the number of bytes, but each byte represents a bit: 1 or 0
}
uint32_t myround2(float f)
{
- if (f >= 2000) return 2000;//something bad happened
- return (uint32_t) (f + (float)0.5);
+ if (f >= 2000) return 2000;//something bad happened
+ return (uint32_t) (f + (float)0.5);
}
-//translate 11111100000 to 10
-size_t aggregate_bits(uint8_t *dest,size_t size, uint8_t rfLen, uint8_t maxConsequtiveBits, uint8_t invert,uint8_t fchigh,uint8_t fclow )// uint8_t h2l_crossing_value,uint8_t l2h_crossing_value,
+//translate 11111100000 to 10
+size_t aggregate_bits(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t maxConsequtiveBits,
+ uint8_t invert, uint8_t fchigh, uint8_t fclow)
{
- uint8_t lastval=dest[0];
- uint32_t idx=0;
- size_t numBits=0;
- uint32_t n=1;
+ uint8_t lastval=dest[0];
+ uint32_t idx=0;
+ size_t numBits=0;
+ uint32_t n=1;
- for( idx=1; idx < size; idx++) {
+ for( idx=1; idx < size; idx++) {
- if (dest[idx]==lastval) {
- n++;
- continue;
- }
- //if lastval was 1, we have a 1->0 crossing
- if ( dest[idx-1]==1 ) {
- n=myround2((float)(n+1)/((float)(rfLen)/(float)fclow));
- //n=(n+1) / h2l_crossing_value;
- } else {// 0->1 crossing
- n=myround2((float)(n+1)/((float)(rfLen-2)/(float)fchigh)); //-2 for fudge factor
- //n=(n+1) / l2h_crossing_value;
- }
- if (n == 0) n = 1;
-
- if(n < maxConsequtiveBits) //Consecutive
- {
- if(invert==0){ //invert bits
- memset(dest+numBits, dest[idx-1] , n);
- }else{
- memset(dest+numBits, dest[idx-1]^1 , n);
- }
- numBits += n;
- }
- n=0;
- lastval=dest[idx];
- }//end for
- return numBits;
+ if (dest[idx]==lastval) {
+ n++;
+ continue;
+ }
+ //if lastval was 1, we have a 1->0 crossing
+ if ( dest[idx-1]==1 ) {
+ n=myround2((float)(n+1)/((float)(rfLen)/(float)fclow));
+ } else {// 0->1 crossing
+ n=myround2((float)(n+1)/((float)(rfLen-1)/(float)fchigh)); //-1 for fudge factor
+ }
+ if (n == 0) n = 1;
+
+ if(n < maxConsequtiveBits) //Consecutive
+ {
+ if(invert==0){ //invert bits
+ memset(dest+numBits, dest[idx-1] , n);
+ }else{
+ memset(dest+numBits, dest[idx-1]^1 , n);
+ }
+ numBits += n;
+ }
+ n=0;
+ lastval=dest[idx];
+ }//end for
+ 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)
{
- // FSK demodulator
- size = fsk_wave_demod(dest, size, fchigh, fclow);
- size = aggregate_bits(dest, size,rfLen,192,invert,fchigh,fclow);
- return size;
+ // FSK demodulator
+ size = fsk_wave_demod(dest, size, fchigh, fclow);
+ size = aggregate_bits(dest, size, rfLen, 192, invert, fchigh, fclow);
+ return 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)
{
+ if (justNoise(dest, *size)) return -1;
- size_t idx=0; //, found=0; //size=0,
- // FSK demodulator
- size = fskdemod(dest, size,50,0,10,8);
-
- // final loop, go over previously decoded manchester data and decode into usable tag ID
- // 111000 bit pattern represent start of frame, 01 pattern represents a 1 and 10 represents a 0
- uint8_t frame_marker_mask[] = {1,1,1,0,0,0};
- int numshifts = 0;
- idx = 0;
- //one scan
- while( idx + sizeof(frame_marker_mask) < size) {
- // search for a start of frame marker
- if ( memcmp(dest+idx, frame_marker_mask, sizeof(frame_marker_mask)) == 0)
- { // frame marker found
- idx+=sizeof(frame_marker_mask);
- while(dest[idx] != dest[idx+1] && idx < size-2)
- {
- // Keep going until next frame marker (or error)
- // Shift in a bit. Start by shifting high registers
- *hi2 = (*hi2<<1)|(*hi>>31);
- *hi = (*hi<<1)|(*lo>>31);
- //Then, shift in a 0 or one into low
- if (dest[idx] && !dest[idx+1]) // 1 0
- *lo=(*lo<<1)|0;
- else // 0 1
- *lo=(*lo<<1)|1;
- numshifts++;
- idx += 2;
- }
- // Hopefully, we read a tag and hit upon the next frame marker
- if(idx + sizeof(frame_marker_mask) < size)
- {
- if ( memcmp(dest+idx, frame_marker_mask, sizeof(frame_marker_mask)) == 0)
- {
- //good return
- return idx;
- }
- }
- // reset
- *hi2 = *hi = *lo = 0;
- numshifts = 0;
- }else {
- idx++;
- }
+ size_t numStart=0, size2=*size, startIdx=0;
+ // FSK demodulator
+ *size = fskdemod(dest, size2,50,1,10,8); //fsk2a
+ if (*size < 96) 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
+
+ numStart = startIdx + sizeof(preamble);
+ // final loop, go over previously decoded FSK data and manchester decode into usable tag ID
+ for (size_t idx = numStart; (idx-numStart) < *size - sizeof(preamble); idx+=2){
+ if (dest[idx] == dest[idx+1]){
+ return -4; //not manchester data
}
- return -1;
+ *hi2 = (*hi2<<1)|(*hi>>31);
+ *hi = (*hi<<1)|(*lo>>31);
+ //Then, shift in a 0 or one into low
+ if (dest[idx] && !dest[idx+1]) // 1 0
+ *lo=(*lo<<1)|1;
+ else // 0 1
+ *lo=(*lo<<1)|0;
+ }
+ return (int)startIdx;
}
-uint32_t bytebits_to_byte(uint8_t* src, int numbits)
+// 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)
{
- uint32_t num = 0;
- for(int i = 0 ; i < numbits ; i++)
- {
- num = (num << 1) | (*src);
- src++;
- }
- return num;
+ if (justNoise(dest, *size)) return -1;
+
+ 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
+
+ numStart = startIdx + sizeof(preamble);
+ // final loop, go over previously decoded FSK data and manchester decode into usable tag ID
+ for (size_t idx = numStart; (idx-numStart) < *size - sizeof(preamble); idx+=2){
+ if (dest[idx] == dest[idx+1])
+ return -4; //not manchester data
+ *hi2 = (*hi2<<1)|(*hi>>31);
+ *hi = (*hi<<1)|(*lo>>31);
+ //Then, shift in a 0 or one into low
+ if (dest[idx] && !dest[idx+1]) // 1 0
+ *lo=(*lo<<1)|1;
+ else // 0 1
+ *lo=(*lo<<1)|0;
+ }
+ 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;
}
int IOdemodFSK(uint8_t *dest, size_t size)
{
- uint32_t idx=0;
- //make sure buffer has data
- if (size < 66) return -1;
- //test samples are not just noise
- uint8_t testMax=0;
- for(idx=0;idx<65;idx++){
- if (testMax<dest[idx]) testMax=dest[idx];
- }
- idx=0;
- //if not just noise
- if (testMax>20){
- // FSK demodulator
- size = fskdemod(dest, size,64,1,10,8); // RF/64 and invert
- if (size < 65) return -1; //did we get a good demod?
- //Index map
- //0 10 20 30 40 50 60
- //| | | | | | |
- //01234567 8 90123456 7 89012345 6 78901234 5 67890123 4 56789012 3 45678901 23
- //-----------------------------------------------------------------------------
- //00000000 0 11110000 1 facility 1 version* 1 code*one 1 code*two 1 ???????? 11
- //
- //XSF(version)facility:codeone+codetwo
- //Handle the data
- uint8_t mask[] = {0,0,0,0,0,0,0,0,0,1};
- for( idx=0; idx < (size - 65); idx++) {
- if ( memcmp(dest + idx, mask, sizeof(mask))==0) {
- //frame marker found
- if (!dest[idx+8] && dest[idx+17]==1 && dest[idx+26]==1 && dest[idx+35]==1 && dest[idx+44]==1 && dest[idx+53]==1){
- //confirmed proper separator bits found
- //return start position
- return (int) idx;
- }
- }
- }
- }
- return 0;
+ if (justNoise(dest, size)) return -1;
+ //make sure buffer has data
+ if (size < 66*64) return -2;
+ // FSK demodulator
+ size = fskdemod(dest, size, 64, 1, 10, 8); // FSK2a RF/64
+ if (size < 65) return -3; //did we get a good demod?
+ //Index map
+ //0 10 20 30 40 50 60
+ //| | | | | | |
+ //01234567 8 90123456 7 89012345 6 78901234 5 67890123 4 56789012 3 45678901 23
+ //-----------------------------------------------------------------------------
+ //00000000 0 11110000 1 facility 1 version* 1 code*one 1 code*two 1 ???????? 11
+ //
+ //XSF(version)facility:codeone+codetwo
+ //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 (!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
+ //return start position
+ return (int) startIdx;
+ }
+ return -5;
+}
+
+// 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), 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 (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;
+}
+
+// by marshmellow
+// FSK Demod then try to locate an AWID ID
+int AWIDdemodFSK(uint8_t *dest, size_t *size)
+{
+ //make sure buffer has enough data
+ if (*size < 96*50) return -1;
+
+ if (justNoise(dest, *size)) return -2;
+
+ // FSK demodulator
+ *size = fskdemod(dest, *size, 50, 1, 10, 8); // 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};
+ size_t startIdx = 0;
+ uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
+ if (errChk == 0) return -4; //preamble not found
+ if (*size != 96) return -5;
+ return (int)startIdx;
+}
+
+// by marshmellow
+// FSK Demod then try to locate an Farpointe Data (pyramid) ID
+int PyramiddemodFSK(uint8_t *dest, size_t *size)
+{
+ //make sure buffer has data
+ if (*size < 128*50) return -5;
+
+ //test samples are not just noise
+ if (justNoise(dest, *size)) return -1;
+
+ // 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
+ if (*size != 128) return -3;
+ return (int)startIdx;
}
// by marshmellow
// maybe somehow adjust peak trimming value based on samples to fix?
int DetectASKClock(uint8_t dest[], size_t size, int clock)
{
- int i=0;
- int peak=0;
- int low=128;
- int clk[]={16,32,40,50,64,100,128,256};
- int loopCnt = 256; //don't need to loop through entire array...
- if (size<loopCnt) loopCnt = size;
-
- //if we already have a valid clock quit
- for (;i<8;++i)
- if (clk[i]==clock) return clock;
-
- //get high and low peak
- for (i=0;i<loopCnt;++i){
- if(dest[i]>peak){
- peak = dest[i];
- }
- if(dest[i]<low){
- low = dest[i];
- }
+ int i=0;
+ int clk[]={8,16,32,40,50,64,100,128,256};
+ int loopCnt = 256; //don't need to loop through entire array...
+ if (size<loopCnt) loopCnt = size;
+
+ //if we already have a valid clock quit
+
+ for (;i<8;++i)
+ if (clk[i] == clock) return clock;
+
+ //get high and low peak
+ int peak, low;
+ getHiLo(dest, loopCnt, &peak, &low, 75, 75);
+
+ int ii;
+ int clkCnt;
+ int tol = 0;
+ int bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000,1000};
+ int errCnt=0;
+ //test each valid clock from smallest to greatest to see which lines up
+ for(clkCnt=0; clkCnt < 8; ++clkCnt){
+ if (clk[clkCnt] == 32){
+ tol=1;
+ }else{
+ tol=0;
}
- peak=(int)((peak-128)*.75)+128;
- low= (int)((low-128)*.75)+128;
- int ii;
- int clkCnt;
- int tol = 0;
- int bestErr=1000;
- int errCnt[]={0,0,0,0,0,0,0,0};
- //test each valid clock from smallest to greatest to see which lines up
- for(clkCnt=0; clkCnt<6;++clkCnt){
- if (clk[clkCnt]==32){
- tol=1;
- }else{
- tol=0;
+ bestErr[clkCnt]=1000;
+ //try lining up the peaks by moving starting point (try first 256)
+ for (ii=0; ii < loopCnt; ++ii){
+ if ((dest[ii] >= peak) || (dest[ii] <= low)){
+ errCnt=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){
+ }else if(dest[ii+(i*clk[clkCnt])-tol]>=peak || dest[ii+(i*clk[clkCnt])-tol]<=low){
+ }else if(dest[ii+(i*clk[clkCnt])+tol]>=peak || dest[ii+(i*clk[clkCnt])+tol]<=low){
+ }else{ //error no peak detected
+ errCnt++;
+ }
}
- bestErr=1000;
- //try lining up the peaks by moving starting point (try first 256)
- for (ii=0; ii<loopCnt; ++ii){
- if ((dest[ii]>=peak) || (dest[ii]<=low)){
- errCnt[clkCnt]=0;
- // now that we have the first one lined up test rest of wave array
- for (i=0; i<((int)(size/clk[clkCnt])-1); ++i){
- if (dest[ii+(i*clk[clkCnt])]>=peak || dest[ii+(i*clk[clkCnt])]<=low){
- }else if(dest[ii+(i*clk[clkCnt])-tol]>=peak || dest[ii+(i*clk[clkCnt])-tol]<=low){
- }else if(dest[ii+(i*clk[clkCnt])+tol]>=peak || dest[ii+(i*clk[clkCnt])+tol]<=low){
- }else{ //error no peak detected
- errCnt[clkCnt]++;
- }
- }
- //if we found no errors this is correct one - return this clock
- if(errCnt[clkCnt]==0) return clk[clkCnt];
- //if we found errors see if it is lowest so far and save it as best run
- if(errCnt[clkCnt]<bestErr) bestErr=errCnt[clkCnt];
+ //if we found no errors then we can stop here
+ // this is correct one - return this clock
+ //PrintAndLog("DEBUG: clk %d, err %d, ii %d, i %d",clk[clkCnt],errCnt,ii,i);
+ if(errCnt==0 && clkCnt<6) return clk[clkCnt];
+ //if we found errors see if it is lowest so far and save it as best run
+ if(errCnt<bestErr[clkCnt]) bestErr[clkCnt]=errCnt;
+ }
+ }
+ }
+ uint8_t iii=0;
+ uint8_t best=0;
+ for (iii=0; iii<8; ++iii){
+ if (bestErr[iii]<bestErr[best]){
+ if (bestErr[iii]==0) bestErr[iii]=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;
+ }
+ }
+ }
+ return clk[best];
+}
+
+//by marshmellow
+//detect psk clock by reading #peaks vs no peaks(or errors)
+int DetectpskNRZClock(uint8_t dest[], size_t size, int clock)
+{
+ int i=0;
+ int clk[]={16,32,40,50,64,100,128,256};
+ int loopCnt = 2048; //don't need to loop through entire array...
+ if (size<loopCnt) loopCnt = size;
+
+ //if we already have a valid clock quit
+ for (; i < 7; ++i)
+ if (clk[i] == clock) return clock;
+
+ //get high and low peak
+ int peak, low;
+ getHiLo(dest, loopCnt, &peak, &low, 75, 75);
+
+ //PrintAndLog("DEBUG: peak: %d, low: %d",peak,low);
+ int ii;
+ uint8_t clkCnt;
+ uint8_t tol = 0;
+ int peakcnt=0;
+ int errCnt=0;
+ int bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000};
+ int peaksdet[]={0,0,0,0,0,0,0,0};
+ //test each valid clock from smallest to greatest to see which lines up
+ for(clkCnt=0; clkCnt < 7; ++clkCnt){
+ if (clk[clkCnt] <= 32){
+ tol=1;
+ }else{
+ tol=0;
+ }
+ //try lining up the peaks by moving starting point (try first 256)
+ for (ii=0; ii< loopCnt; ++ii){
+ if ((dest[ii] >= peak) || (dest[ii] <= low)){
+ errCnt=0;
+ 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++;
+ }else if(dest[ii+(i*clk[clkCnt])-tol]>=peak || dest[ii+(i*clk[clkCnt])-tol]<=low){
+ peakcnt++;
+ }else if(dest[ii+(i*clk[clkCnt])+tol]>=peak || dest[ii+(i*clk[clkCnt])+tol]<=low){
+ peakcnt++;
+ }else{ //error no peak detected
+ errCnt++;
+ }
+ }
+ if(peakcnt>peaksdet[clkCnt]) {
+ peaksdet[clkCnt]=peakcnt;
+ bestErr[clkCnt]=errCnt;
+ }
+ }
+ }
+ }
+ int iii=0;
+ int best=0;
+ //int ratio2; //debug
+ int ratio;
+ //int bits;
+ for (iii=0; iii < 7; ++iii){
+ ratio=1000;
+ //ratio2=1000; //debug
+ //bits=size/clk[iii]; //debug
+ if (peaksdet[iii] > 0){
+ ratio=bestErr[iii]/peaksdet[iii];
+ if (((bestErr[best]/peaksdet[best]) > (ratio)+1)){
+ best = iii;
+ }
+ //ratio2=bits/peaksdet[iii]; //debug
+ }
+ //PrintAndLog("DEBUG: Clk: %d, peaks: %d, errs: %d, bestClk: %d, ratio: %d, bits: %d, peakbitr: %d",clk[iii],peaksdet[iii],bestErr[iii],clk[best],ratio, bits,ratio2);
+ }
+ return clk[best];
+}
+
+// by marshmellow (attempt to get rid of high immediately after a low)
+void pskCleanWave(uint8_t *BitStream, size_t size)
+{
+ int i;
+ int gap = 4;
+ int newLow=0;
+ int newHigh=0;
+ int high, low;
+ getHiLo(BitStream, size, &high, &low, 80, 90);
+
+ for (i=0; i < size; ++i){
+ if (newLow == 1){
+ if (BitStream[i]>low){
+ BitStream[i]=low+8;
+ gap--;
+ }
+ if (gap == 0){
+ newLow=0;
+ gap=4;
+ }
+ }else if (newHigh == 1){
+ if (BitStream[i]<high){
+ BitStream[i]=high-8;
+ gap--;
+ }
+ if (gap == 0){
+ newHigh=0;
+ gap=4;
+ }
+ }
+ if (BitStream[i] <= low) newLow=1;
+ if (BitStream[i] >= high) newHigh=1;
+ }
+ return;
+}
+
+// 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 (lastBit!=BitStream[i]){
+ lastBit=BitStream[i];
+ BitStream[i]=1;
+ } else {
+ BitStream[i]=0;
+ }
+ }
+ return;
+}
+
+// redesigned by marshmellow adjusted from existing decode functions
+// indala id decoding - only tested on 26 bit tags, but attempted to make it work for more
+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;
+
+ // Dumping UID
+ i = start;
+ for (ii = 0; ii < bitCnt; ii++) {
+ bitStream[ii] = bitStream[i++];
+ }
+ *size=bitCnt;
+ return 1;
+}
+
+// by marshmellow - demodulate PSK1 wave or NRZ wave (both similar enough)
+// peaks invert bit (high=1 low=0) each clock cycle = 1 bit determined by last peak
+int pskNRZrawDemod(uint8_t *dest, size_t *size, int *clk, int *invert)
+{
+ if (justNoise(dest, *size)) return -1;
+ pskCleanWave(dest,*size);
+ int clk2 = DetectpskNRZClock(dest, *size, *clk);
+ *clk=clk2;
+ uint32_t i;
+ int high, low, ans;
+ ans = getHiLo(dest, 1260, &high, &low, 75, 80); //25% fuzz on high 20% fuzz on low
+ if (ans<1) return -2; //just noise
+ uint32_t gLen = *size;
+ //PrintAndLog("DEBUG - valid high: %d - valid low: %d",high,low);
+ int lastBit = 0; //set first clock check
+ uint32_t bitnum = 0; //output counter
+ 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
+ if (*clk==32) tol = 2; //clock tolerance may not be needed anymore currently set to + or - 1 but could be increased for poor waves or removed entirely
+ uint32_t iii = 0;
+ uint8_t errCnt =0;
+ uint32_t bestStart = *size;
+ uint32_t maxErr = (*size/1000);
+ uint32_t bestErrCnt = maxErr;
+ uint8_t curBit=0;
+ uint8_t bitHigh=0;
+ uint8_t ignorewin=*clk/8;
+ //PrintAndLog("DEBUG - lastbit - %d",lastBit);
+ //loop to find first wave that works - align to clock
+ for (iii=0; iii < gLen; ++iii){
+ if ((dest[iii]>=high) || (dest[iii]<=low)){
+ lastBit=iii-*clk;
+ //loop through to see if this start location works
+ for (i = iii; i < *size; ++i) {
+ //if we found a high bar and we are at a clock bit
+ if ((dest[i]>=high ) && (i>=lastBit+*clk-tol && i<=lastBit+*clk+tol)){
+ bitHigh=1;
+ lastBit+=*clk;
+ ignorewin=*clk/8;
+ bitnum++;
+ //else if low bar found and we are at a clock point
+ }else if ((dest[i]<=low ) && (i>=lastBit+*clk-tol && i<=lastBit+*clk+tol)){
+ bitHigh=1;
+ lastBit+=*clk;
+ ignorewin=*clk/8;
+ bitnum++;
+ //else if no bars found
+ }else if(dest[i] < high && dest[i] > low) {
+ if (ignorewin==0){
+ bitHigh=0;
+ }else ignorewin--;
+ //if we are past a clock point
+ if (i >= lastBit+*clk+tol){ //clock val
+ lastBit+=*clk;
+ bitnum++;
+ }
+ //else if bar found but we are not at a clock bit and we did not just have a clock bit
+ }else if ((dest[i]>=high || dest[i]<=low) && (i<lastBit+*clk-tol || i>lastBit+*clk+tol) && (bitHigh==0)){
+ //error bar found no clock...
+ errCnt++;
+ }
+ if (bitnum>=1000) break;
+ }
+ //we got more than 64 good bits and not all errors
+ if ((bitnum > (64+errCnt)) && (errCnt < (maxErr))) {
+ //possible good read
+ if (errCnt == 0){
+ bestStart = iii;
+ bestErrCnt = errCnt;
+ break; //great read - finish
+ }
+ if (errCnt < bestErrCnt){ //set this as new best run
+ bestErrCnt = errCnt;
+ bestStart = iii;
+ }
+ }
+ }
+ }
+ if (bestErrCnt < maxErr){
+ //best run is good enough set to best run and set overwrite BinStream
+ iii=bestStart;
+ lastBit=bestStart-*clk;
+ bitnum=0;
+ for (i = iii; i < *size; ++i) {
+ //if we found a high bar and we are at a clock bit
+ if ((dest[i] >= high ) && (i>=lastBit+*clk-tol && i<=lastBit+*clk+tol)){
+ bitHigh=1;
+ lastBit+=*clk;
+ curBit=1-*invert;
+ dest[bitnum]=curBit;
+ ignorewin=*clk/8;
+ bitnum++;
+ //else if low bar found and we are at a clock point
+ }else if ((dest[i]<=low ) && (i>=lastBit+*clk-tol && i<=lastBit+*clk+tol)){
+ bitHigh=1;
+ lastBit+=*clk;
+ curBit=*invert;
+ dest[bitnum]=curBit;
+ ignorewin=*clk/8;
+ bitnum++;
+ //else if no bars found
+ }else if(dest[i]<high && dest[i]>low) {
+ if (ignorewin==0){
+ bitHigh=0;
+ }else ignorewin--;
+ //if we are past a clock point
+ if (i>=lastBit+*clk+tol){ //clock val
+ lastBit+=*clk;
+ dest[bitnum]=curBit;
+ bitnum++;
+ }
+ //else if bar found but we are not at a clock bit and we did not just have a clock bit
+ }else if ((dest[i]>=high || dest[i]<=low) && ((i<lastBit+*clk-tol) || (i>lastBit+*clk+tol)) && (bitHigh==0)){
+ //error bar found no clock...
+ bitHigh=1;
+ dest[bitnum]=77;
+ bitnum++;
+ errCnt++;
+ }
+ if (bitnum >=1000) break;
+ }
+ *size=bitnum;
+ } else{
+ *size=bitnum;
+ *clk=bestStart;
+ return -1;
+ }
+
+ if (bitnum>16){
+ *size=bitnum;
+ } else return -1;
+ return errCnt;
+}
+
+//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 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};
+ uint8_t rfLensFnd = 0;
+ uint8_t lastFCcnt=0;
+ uint32_t fcCounter = 0;
+ uint16_t rfCounter = 0;
+ uint8_t firstBitFnd = 0;
+ size_t i;
+
+ uint8_t fcTol = (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++)
+ if (BitStream[i] > BitStream[i-1] && BitStream[i]>=BitStream[i+1])
+ break;
+
+ for (; i < size-1; i++){
+ if (BitStream[i] > BitStream[i-1] && BitStream[i]>=BitStream[i+1]){
+ // new peak
+ fcCounter++;
+ rfCounter++;
+ // if we got less than the small fc + tolerance then set it to the small fc
+ if (fcCounter < fcLow+fcTol)
+ fcCounter = fcLow;
+ else //set it to the large fc
+ fcCounter = fcHigh;
+
+ //look for bit clock (rf/xx)
+ if ((fcCounter<lastFCcnt || fcCounter>lastFCcnt)){
+ //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){
+ rfCnts[ii]++;
+ rfCounter=0;
+ break;
}
+ }
+ if (rfCounter>0 && rfLensFnd<15){
+ //PrintAndLog("DEBUG: rfCntr %d, fcCntr %d",rfCounter,fcCounter);
+ rfCnts[rfLensFnd]++;
+ rfLens[rfLensFnd++]=rfCounter;
+ }
+ } else {
+ firstBitFnd++;
}
+ rfCounter=0;
+ lastFCcnt=fcCounter;
+ }
+ fcCounter=0;
+ } else {
+ // count sample
+ fcCounter++;
+ rfCounter++;
}
- int iii=0;
- int best=0;
- for (iii=0; iii<6;++iii){
- if (errCnt[iii]<errCnt[best]){
- best = iii;
+ }
+ 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;
+ rfHighest2=rfHighest;
+ rfHighest=i;
+ } else if(rfCnts[i]>rfCnts[rfHighest2]){
+ rfHighest3=rfHighest2;
+ rfHighest2=i;
+ } else if(rfCnts[i]>rfCnts[rfHighest3]){
+ rfHighest3=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]);
+
+ // loop to find the highest clock that has a remainder less than the tolerance
+ // compare samples counted divided by
+ int ii=7;
+ for (; ii>=0; 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){
+ break;
}
+ }
}
- return clk[best];
+ }
+
+ if (ii<0) return 0; // oops we went too far
+
+ return clk[ii];
+}
+
+//by marshmellow
+//countFC is to detect the field clock lengths.
+//counts and returns the 2 most common wave lengths
+uint16_t countFC(uint8_t *BitStream, size_t size)
+{
+ 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 fcLensFnd = 0;
+ uint8_t lastFCcnt=0;
+ uint32_t fcCounter = 0;
+ size_t i;
+
+ // prime i to first up transition
+ for (i = 1; i < size-1; i++)
+ if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1])
+ break;
+
+ for (; i < size-1; i++){
+ if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1]){
+ // new up transition
+ fcCounter++;
+
+ //if we had 5 and now have 9 then go back to 8 (for when we get a fc 9 instead of an 8)
+ if (lastFCcnt==5 && fcCounter==9) fcCounter--;
+ //if odd and not rc/5 add one (for when we get a fc 9 instead of 10)
+ if ((fcCounter==9 && fcCounter & 1) || fcCounter==4) fcCounter++;
+
+ // save last field clock count (fc/xx)
+ // find which fcLens to save it to:
+ for (int ii=0; ii<10; ii++){
+ if (fcLens[ii]==fcCounter){
+ fcCnts[ii]++;
+ fcCounter=0;
+ break;
+ }
+ }
+ if (fcCounter>0 && fcLensFnd<10){
+ //add new fc length
+ fcCnts[fcLensFnd]++;
+ fcLens[fcLensFnd++]=fcCounter;
+ }
+ fcCounter=0;
+ } else {
+ // count sample
+ fcCounter++;
+ }
+ }
+
+ uint8_t best1=9, best2=9, best3=9;
+ 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);
+ // get the 3 best FC values
+ if (fcCnts[i]>maxCnt1) {
+ best3=best2;
+ best2=best1;
+ maxCnt1=fcCnts[i];
+ best1=i;
+ } else if(fcCnts[i]>fcCnts[best2]){
+ best3=best2;
+ best2=i;
+ } else if(fcCnts[i]>fcCnts[best3]){
+ best3=i;
+ }
+ }
+ uint8_t fcH=0, fcL=0;
+ if (fcLens[best1]>fcLens[best2]){
+ fcH=fcLens[best1];
+ fcL=fcLens[best2];
+ } else{
+ fcH=fcLens[best2];
+ fcL=fcLens[best1];
+ }
+
+ // 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]);
+
+ return fcs;
}
projects / proxmark3-svn / blobdiff