// Low frequency commands
//-----------------------------------------------------------------------------
+#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "lfdemod.h"
//by marshmellow
//takes 1s and 0s and searches for EM410x format - output EM ID
-uint64_t Em410xDecode(uint8_t *BitStream,uint32_t BitLen)
+uint64_t Em410xDecode(uint8_t *BitStream, uint32_t BitLen)
{
- //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,
+ //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;
+ 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];
+ }
- uint32_t i = 0;
- uint32_t initLoopMax = 65;
- if (initLoopMax>BitLen) initLoopMax=BitLen;
+ if (((high !=1)||(low !=0))){ //allow only 1s and 0s
+ 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 j = 0;
+ uint8_t resetCnt = 0;
+ while( (idx + 64) < BitLen) {
+
+ restart:
- 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++;
- }
- }
- return 0;
+ 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( j = 0; j < 5; ++j){
+ parityTest += BitStream[(i*5) + j + idx];
+ }
+ if (parityTest == ( (parityTest >> 1) << 1)){
+ parityTest = 0;
+ for (j = 0; j < 4; ++j){
+ lo = ( lo << 1LL)|( BitStream[( i * 5 ) + j + idx]);
+ }
+ } else {
+ //parity failed
+ 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++;
+ }
+ }
+ return 0;
}
//by marshmellow
//takes 2 arguments - clock and invert both as integers
//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, uint32_t *BitLen, 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 != 1) *invert=0;
+ 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 != 1) *invert = 0;
+
+ uint32_t initLoopMax = 200;
+ if (initLoopMax > *BitLen)
+ initLoopMax = *BitLen;
- uint32_t initLoopMax = 200;
- if (initLoopMax>*BitLen) initLoopMax=*BitLen;
+ // Detect high and lows
+ // 200 samples should be enough to find high and low values
+ for (i = 0; i < initLoopMax; ++i) {
+ if (BinStream[i] > high)
+ high = BinStream[i];
+ else if (BinStream[i] < low)
+ low = BinStream[i];
+ }
- // 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
- 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;
+ //throw away static
+ if ((high < 158) )
+ return -2;
+
+ //25% fuzz in case highs and lows aren't clipped [marshmellow]
+ high = (int)(high * .75);
+ low = (int)(low+128 * .25);
- //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);
+ int lastBit = 0; // set first clock check
+ uint32_t bitnum = 0; // output counter
+
+ // clock tolerance adjust - waves will be accepted as within the clock if they fall + or - this value + clock from last valid wave
+ //clock tolerance may not be needed anymore currently set to + or - 1 but could be increased for poor waves or removed entirely
+ int tol = ( *clk == 32 ) ? 1 : 0;
+
+ int j = 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 = bestErrCnt;
//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;
+ for (j=0; j < gLen; ++j){
+
+ if ((BinStream[j] >= high)||(BinStream[j] <= low)){
+ lastBit = j - *clk;
+ errCnt = 0;
+
//loop through to see if this start location works
- for (i = iii; i < *BitLen; ++i) {
+ for (i = j; i < *BitLen; ++i) {
if ((BinStream[i] >= high) && ((i-lastBit)>(*clk-tol))){
- lastBit+=*clk;
+ lastBit += *clk;
} else if ((BinStream[i] <= low) && ((i-lastBit)>(*clk-tol))){
//low found and we are expecting a bar
- lastBit+=*clk;
+ lastBit += *clk;
} else {
//mid value found or no bar supposed to be here
- if ((i-lastBit)>(*clk+tol)){
+ if ((i-lastBit) > (*clk + tol)){
//should have hit a high or low based on clock!!
errCnt++;
- lastBit+=*clk;//skip over until hit too many errors
- if (errCnt>(maxErr)) break; //allow 1 error for every 1000 samples else start over
+ 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
+ if ((i-j) >(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)) {
+ if ((((i-j)/ *clk) > (64 + errCnt)) && (errCnt < maxErr)) {
//possible good read
- if (errCnt==0){
- bestStart=iii;
- bestErrCnt=errCnt;
+ if (errCnt == 0){
+ bestStart = j;
+ bestErrCnt = errCnt;
break; //great read - finish
}
- if (errCnt<bestErrCnt){ //set this as new best run
- bestErrCnt=errCnt;
- bestStart = iii;
+ if (errCnt < bestErrCnt){ //set this as new best run
+ bestErrCnt = errCnt;
+ bestStart = j;
}
}
}
}
- if (bestErrCnt<maxErr){
+ 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!!
-
- 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;
- }
+ j = bestStart;
+ lastBit = bestStart - *clk;
+ bitnum = 0;
+ for (i = j; 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!!
+ if (bitnum > 0){
+ BinStream[bitnum] = 77;
+ bitnum++;
+ }
+ lastBit += *clk;//skip over error
+ }
+ }
+ if (bitnum >= 400) break;
+ }
+ *BitLen = bitnum;
+ } else {
+ *invert = bestStart;
+ *clk = j;
+ return -1;
+ }
return bestErrCnt;
}
//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 * bits, int *bitlen)
{
- int bitnum=0;
- int errCnt =0;
- int i=1;
+ int bitnum = 0;
+ int errCnt = 0;
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;
+ int i = 1;
+ int j = 1;
+
+ for (; j < 3; ++j){
+ i = 1;
+ for ( i = i + j; i < *bitlen-2; i += 2){
+ if ( bits[i]==1 && (bits[i+1]==0)){
+ } else if ((bits[i]==0)&& bits[i+1]==1){
+ } else {
+ errCnt++;
+ }
+ if(bitnum > 300) break;
}
- if (bestErr>errCnt){
- bestErr=errCnt;
- bestRun=ii;
+ if (bestErr > errCnt){
+ bestErr = errCnt;
+ bestRun = j;
}
- 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;
+ errCnt = 0;
+ }
+ errCnt = bestErr;
+ if (errCnt < 20){
+ j = bestRun;
+ i = 1;
+ for ( i = i+j; i < *bitlen-2; i += 2){
+ if ( bits[i] == 1 && bits[i + 1] == 0 ){
+ bits[bitnum++] = 0;
+ } else if ( bits[i] == 0 && bits[i + 1] == 1 ){
+ bits[bitnum++] = 1;
+ } else {
+ bits[bitnum++] = 77;
+ }
+ if ( bitnum > 300 ) break;
}
- *bitLen=bitnum;
+ *bitlen = bitnum;
}
- return errCnt;
+ 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 * bits, int *bitlen, int offset)
{
- 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;
+ uint8_t bitnum = 0;
+ uint32_t errCnt = 0;
+ uint32_t i = offset;
+
+ for (; i < *bitlen-2; i += 2 ){
+ if ( (bits[i]==1 && bits[i+1]==0)||
+ (bits[i]==0 && bits[i+1]==1)){
+ bits[bitnum++] = 1;
+ } else if ( (bits[i]==0 && bits[i+1]==0)||
+ (bits[i]==1 && bits[i+1]==1)){
+ bits[bitnum++] = 0;
+ } else {
+ bits[bitnum++] = 77;
+ errCnt++;
+ }
+ if ( bitnum > 250) break;
}
- *bitLen=bitnum;
- return errCnt;
+ *bitlen = 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, int *bitLen, int *clk, int *invert)
{
uint32_t i;
- // int invert=0; //invert default
+ uint32_t initLoopMax = 200;
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;
+ uint8_t BitStream[502] = {0x00};
+
+ *clk = DetectASKClock(BinStream, *bitLen, *clk); //clock default
+
+ if (*clk < 8) *clk = 64;
+ if (*clk < 32) *clk = 32;
if (*invert != 1) *invert = 0;
+
+ if (initLoopMax > *bitLen)
+ initLoopMax = *bitLen;
- 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];
+ high = BinStream[i];
else if (BinStream[i] < low)
- low = BinStream[i];
+ low = BinStream[i];
}
- if ((high < 158)){ //throw away static
- 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;
-
- 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;
+
+ //throw away static
+ if ((high < 158)){
+ return -2;
+ }
+
+ //25% fuzz in case highs and lows aren't clipped [marshmellow]
+ high = (int)(high * .75);
+ low = (int)(low+128 * .25);
+
+ 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 gLen = *bitLen;
- if (gLen > 500) gLen=500;
- uint8_t errCnt =0;
- uint32_t bestStart = *bitLen;
- uint32_t bestErrCnt = (*bitLen/1000);
- uint8_t midBit=0;
+ if (gLen > 500) gLen = 500;
+ uint32_t j = 0;
+ uint8_t errCnt = 0;
+ uint32_t bestStart = *bitLen;
+ uint32_t bestErrCnt = (*bitLen / 1000);
+ uint32_t errCntLimit = bestErrCnt;
+ uint8_t midBit = 0;
+
//loop to find first wave that works
- for (iii=0; iii < gLen; ++iii){
- if ((BinStream[iii]>=high)||(BinStream[iii]<=low)){
- lastBit=iii-*clk;
+ for (j = 0; j < gLen; ++j){
+
+ if ((BinStream[j] >= high)||(BinStream[j] <= low)){
+ lastBit = j - *clk;
//loop through to see if this start location works
- for (i = iii; i < *bitLen; ++i) {
+ for (i = j; i < *bitLen; ++i) {
if ((BinStream[i] >= high) && ((i-lastBit)>(*clk-tol))){
- lastBit+=*clk;
+ lastBit += *clk;
BitStream[bitnum] = *invert;
bitnum++;
- midBit=0;
+ midBit = 0;
} else if ((BinStream[i] <= low) && ((i-lastBit)>(*clk-tol))){
//low found and we are expecting a bar
- lastBit+=*clk;
+ 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;
+ 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;
+ 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];
+ midBit = 1;
+ BitStream[bitnum] = BitStream[bitnum-1];
bitnum++;
} else {
//mid value found or no bar supposed to be here
- if ((i-lastBit)>(*clk+tol)){
+ if (( i - lastBit) > ( *clk + tol)){
//should have hit a high or low based on clock!!
if (bitnum > 0){
- BitStream[bitnum]=77;
+ 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
+ lastBit += *clk;//skip over until hit too many errors
+ if (errCnt > errCntLimit){ //allow 1 error for every 1000 samples else start over
+ errCnt = 0;
+ bitnum = 0;//start over
break;
}
}
}
- if (bitnum>500) 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;
+ //possible good read
+ if ((bitnum > (64 + errCnt)) && (errCnt < errCntLimit)) {
+
+ //great read - finish
+ if (errCnt == 0) break;
+
+ //if current run == bestErrCnt run (after exhausted testing) then finish
+ if (bestStart == j) break;
+
+ //set this as new best run
+ if (errCnt < bestErrCnt){
+ bestErrCnt = errCnt;
+ bestStart = j;
}
}
}
- if (iii>=gLen){ //exhausted test
+ if (j >= 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 (bestErrCnt < errCntLimit)
+ j = bestStart;
}
}
- if (bitnum>16){
+ if (bitnum > 16){
- for (i=0; i < bitnum; ++i){
- BinStream[i]=BitStream[i];
+ for (i = 0; i < bitnum; ++i){
+ BinStream[i] = BitStream[i];
}
*bitLen = bitnum;
} else {
{
uint32_t last_transition = 0;
uint32_t idx = 1;
- uint32_t maxVal=0;
- if (fchigh==0) fchigh=10;
- if (fclow==0) fclow=8;
+ 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];
- }
+ if ( size < 100)
+ return 0;
+
+ // Find high from first 100 samples
+ 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);
+ uint8_t threshold_value = (uint8_t)(maxVal * .75);
// 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;
+ dest[0] = (dest[0] < threshold_value) ? 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;
+ // threshold current value
+ dest[idx] = (dest[idx] < threshold_value) ? 0 : 1;
// Check for 0->1 transition
if (dest[idx-1] < dest[idx]) { // 0 -> 1 transition
- if ((idx-last_transition)<(fclow-2)){ //0-5 = garbage noise
+ if ( ( 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
+ } else if ((idx - last_transition) < ( fchigh - 1 )) { //6-8 = 8 waves
dest[numBits]=1;
} else { //9+ = 10 waves
dest[numBits]=0;
numBits++;
}
}
- return numBits; //Actually, it returns the number of bytes, but each byte represents a bit: 1 or 0
+ //it returns the number of bytes, but each byte represents a bit: 1 or 0
+ return numBits;
}
uint32_t myround2(float f)
}
//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,
+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;
+ uint32_t n = 1;
+ size_t numBits = 0;
- for( idx=1; idx < size; idx++) {
+ for( idx = 1; idx < size; idx++) {
- if (dest[idx]==lastval) {
+ 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 ( dest[idx-1] == 1 ) {
+ n = myround2( (float)( n + 1 ) / ((float)(rfLen)/(float)fclow));
+ } else { // 0->1 crossing
+ n = myround2( (float)( n + 1 ) / ((float)(rfLen-2)/(float)fchigh)); //-2 for fudge factor
}
if (n == 0) n = 1;
if(n < maxConsequtiveBits) //Consecutive
{
- if(invert==0){ //invert bits
+ 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];
+ 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);
+ if ( size > 0 )
+ size = aggregate_bits(dest, size, rfLen, 192, invert, fchigh, fclow);
+ else
+ return -1;
+ 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)
{
-
- size_t idx=0; //, found=0; //size=0,
+ size_t idx = 0;
+ int numshifts = 0;
+
// FSK demodulator
- size = fskdemod(dest, size,50,0,10,8);
+ 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;
+
+ uint8_t mask_len = sizeof frame_marker_mask / sizeof frame_marker_mask[0];
+
//one scan
- while( idx + sizeof(frame_marker_mask) < size) {
+ while( idx + mask_len < 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);
+ idx += mask_len;
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);
+ *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;
+ *lo = ( *lo << 1 ) | 0;
else // 0 1
- *lo=(*lo<<1)|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(idx + mask_len < size)
{
if ( memcmp(dest+idx, frame_marker_mask, sizeof(frame_marker_mask)) == 0)
{
return -1;
}
-uint32_t bytebits_to_byte(uint8_t* src, int numbits)
+uint32_t bytebits_to_byte(uint8_t *src, int numbits)
{
+ //HACK: potential overflow in numbits is larger then uint32 bits.
+
uint32_t num = 0;
- for(int i = 0 ; i < numbits ; i++) {
+ for(int i = 0 ; i < numbits ; ++i) {
num = (num << 1) | (*src);
src++;
}
int IOdemodFSK(uint8_t *dest, size_t size)
{
- uint32_t idx=0;
//make sure buffer has data
- if (size < 66) return -1;
+ if (size < 100) return -1;
+
+ uint32_t idx = 0;
+ uint8_t testMax = 0;
+
//test samples are not just noise
- uint8_t testMax=0;
- for(idx=0;idx<65;idx++){
- if (testMax<dest[idx]) testMax=dest[idx];
+ for (; idx < 65; ++idx ){
+ if (testMax < dest[idx])
+ testMax = dest[idx];
}
- idx=0;
+
//if not just noise
- if (testMax>170){
- // 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;
- }
- }
- }
- }
+ if (testMax < 170) return -2;
+
+ // FSK demodulator
+ size = fskdemod(dest, size, 64, 1, 10, 8); // RF/64 and invert
+
+ //did we get a good demod?
+ if (size < 65) return -3;
+
+ //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;
}
// 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];
- }
- }
- 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=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];
- }
- }
- }
- int iii=0;
- int best=0;
- for (iii=0; iii<6;++iii){
- if (errCnt[iii]<errCnt[best]){
- best = iii;
- }
- }
- return clk[best];
+ int i = 0;
+ int clk[] = {16,32,40,50,64,100,128,256};
+ uint8_t clkLen = sizeof clk / sizeof clk[0];
+
+ //if we already have a valid clock quit
+ for (; i < clkLen; ++i)
+ if (clk[i] == clock)
+ return clock;
+
+ int peak = 0;
+ int low = 128;
+ int loopCnt = 256;
+ if (size < loopCnt)
+ loopCnt = size;
+
+ //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];
+ }
+
+ peak = (int)(peak * .75);
+ low = (int)(low+128 * .25);
+
+ int ii, cnt, bestErr, tol = 0;
+ int errCnt[clkLen];
+ memset(errCnt, 0x00, clkLen);
+
+ int tmpIndex, tmphigh, tmplow;
+
+ //test each valid clock from smallest to greatest to see which lines up
+ for( cnt = 0; cnt < clkLen; ++cnt ){
+
+ tol = (clk[cnt] == 32) ? 1 : 0;
+ bestErr = 1000;
+ tmpIndex = tmphigh = tmplow = 0;
+
+ //try lining up the peaks by moving starting point (try first 256)
+ for (ii=0; ii < loopCnt; ++ii){
+
+ // not a peak? continue
+ if ( (dest[ii] < peak) && (dest[ii] > low))
+ continue;
+
+ errCnt[cnt] = 0;
+
+ // now that we have the first one lined up test rest of wave array
+ for ( i = 0; i < ((int)(size / clk[cnt]) - 1); ++i){
+
+ tmpIndex = ii + (i * clk[cnt] );
+ tmplow = dest[ tmpIndex - tol];
+ tmphigh = dest[ tmpIndex + tol];
+
+ if ( dest[tmpIndex] >= peak || dest[tmpIndex] <= low ) {
+ }
+ else if ( tmplow >= peak || tmplow <= low){
+ }
+ else if ( tmphigh >= peak || tmphigh <= low){
+ }
+ else
+ errCnt[cnt]++; //error no peak detected
+ }
+
+ //if we found no errors this is correct one - return this clock
+ if ( errCnt[cnt] == 0 )
+ return clk[cnt];
+
+ if ( errCnt[cnt] < bestErr)
+ bestErr = errCnt[cnt];
+ }
+ // save the least error.
+ errCnt[cnt] = bestErr;
+ }
+ // find best clock which has lowest number of errors
+ int j = 0, bestIndex = 0;
+ for (; j < clkLen; ++j){
+ if ( errCnt[j] < errCnt[bestIndex] )
+ bestIndex = j;
+ }
+ return clk[bestIndex];
}
projects / proxmark3-svn / blobdiff