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1e090a61a1
data fskfcdetect (field clock and bit clock detect for FSK) data fskdemodawid -AWID demod/decode data fskdemodpyramid - AWID demod/decode
1279 lines
38 KiB
C
1279 lines
38 KiB
C
//-----------------------------------------------------------------------------
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// Copyright (C) 2014
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//
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// This code is licensed to you under the terms of the GNU GPL, version 2 or,
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// at your option, any later version. See the LICENSE.txt file for the text of
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// the license.
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//-----------------------------------------------------------------------------
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// Low frequency demod/decode commands
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//-----------------------------------------------------------------------------
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#include <stdlib.h>
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#include <string.h>
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#include "lfdemod.h"
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//by marshmellow
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//get high and low with passed in fuzz factor. also return noise test = 1 for passed or 0 for only noise
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int getHiLo(uint8_t *BitStream, size_t size, int *high, int *low, uint8_t fuzzHi, uint8_t fuzzLo)
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{
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*high=0;
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*low=255;
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// get high and low thresholds
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for (int i=0; i < size; i++){
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if (BitStream[i] > *high) *high = BitStream[i];
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if (BitStream[i] < *low) *low = BitStream[i];
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}
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if (*high < 123) return -1; // just noise
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*high = (int)(((*high-128)*(((float)fuzzHi)/100))+128);
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*low = (int)(((*low-128)*(((float)fuzzLo)/100))+128);
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return 1;
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}
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//by marshmellow
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//takes 1s and 0s and searches for EM410x format - output EM ID
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uint64_t Em410xDecode(uint8_t *BitStream, size_t size)
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{
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//no arguments needed - built this way in case we want this to be a direct call from "data " cmds in the future
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// otherwise could be a void with no arguments
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//set defaults
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uint64_t lo=0;
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uint32_t i = 0;
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if (BitStream[10]>1){ //allow only 1s and 0s
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// PrintAndLog("no data found");
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return 0;
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}
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uint8_t parityTest=0;
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// 111111111 bit pattern represent start of frame
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uint8_t frame_marker_mask[] = {1,1,1,1,1,1,1,1,1};
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uint32_t idx = 0;
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uint32_t ii=0;
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uint8_t resetCnt = 0;
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while( (idx + 64) < size) {
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restart:
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// search for a start of frame marker
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if ( memcmp(BitStream+idx, frame_marker_mask, sizeof(frame_marker_mask)) == 0)
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{ // frame marker found
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idx+=9;
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for (i=0; i<10;i++){
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for(ii=0; ii<5; ++ii){
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parityTest ^= BitStream[(i*5)+ii+idx];
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}
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if (!parityTest){
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parityTest=0;
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for (ii=0; ii<4;++ii){
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lo=(lo<<1LL)|(BitStream[(i*5)+ii+idx]);
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}
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//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);
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}else {//parity failed
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//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]);
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parityTest=0;
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idx-=8;
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if (resetCnt>5)return 0; //try 5 times
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resetCnt++;
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goto restart;//continue;
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}
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}
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//skip last 5 bit parity test for simplicity.
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return lo;
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}else{
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idx++;
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}
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}
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return 0;
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}
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//by marshmellow
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//takes 2 arguments - clock and invert both as integers
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//attempts to demodulate ask while decoding manchester
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//prints binary found and saves in graphbuffer for further commands
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int askmandemod(uint8_t *BinStream, size_t *size, int *clk, int *invert)
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{
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int i;
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*clk=DetectASKClock(BinStream, *size, *clk); //clock default
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if (*clk<8) *clk =64;
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if (*clk<32) *clk=32;
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if (*invert != 0 && *invert != 1) *invert=0;
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uint32_t initLoopMax = 200;
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if (initLoopMax > *size) initLoopMax=*size;
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// Detect high and lows
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// 25% fuzz in case highs and lows aren't clipped [marshmellow]
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int high, low, ans;
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ans = getHiLo(BinStream, initLoopMax, &high, &low, 75, 75);
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if (ans<1) return -2; //just noise
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// PrintAndLog("DEBUG - valid high: %d - valid low: %d",high,low);
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int lastBit = 0; //set first clock check
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uint32_t bitnum = 0; //output counter
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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
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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
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int iii = 0;
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uint32_t gLen = *size;
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if (gLen > 3000) gLen=3000;
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uint8_t errCnt =0;
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uint32_t bestStart = *size;
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uint32_t bestErrCnt = (*size/1000);
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uint32_t maxErr = (*size/1000);
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// PrintAndLog("DEBUG - lastbit - %d",lastBit);
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// loop to find first wave that works
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for (iii=0; iii < gLen; ++iii){
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if ((BinStream[iii] >= high) || (BinStream[iii] <= low)){
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lastBit=iii-*clk;
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errCnt=0;
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// loop through to see if this start location works
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for (i = iii; i < *size; ++i) {
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if ((BinStream[i] >= high) && ((i-lastBit) > (*clk-tol))){
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lastBit+=*clk;
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} else if ((BinStream[i] <= low) && ((i-lastBit) > (*clk-tol))){
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//low found and we are expecting a bar
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lastBit+=*clk;
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} else {
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//mid value found or no bar supposed to be here
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if ((i-lastBit)>(*clk+tol)){
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//should have hit a high or low based on clock!!
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//debug
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//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);
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errCnt++;
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lastBit+=*clk;//skip over until hit too many errors
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if (errCnt>(maxErr)) break; //allow 1 error for every 1000 samples else start over
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}
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}
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if ((i-iii) >(400 * *clk)) break; //got plenty of bits
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}
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//we got more than 64 good bits and not all errors
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if ((((i-iii)/ *clk) > (64+errCnt)) && (errCnt<maxErr)) {
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//possible good read
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if (errCnt==0){
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bestStart=iii;
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bestErrCnt=errCnt;
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break; //great read - finish
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}
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if (errCnt<bestErrCnt){ //set this as new best run
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bestErrCnt=errCnt;
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bestStart = iii;
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}
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}
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}
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}
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if (bestErrCnt<maxErr){
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//best run is good enough set to best run and set overwrite BinStream
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iii=bestStart;
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lastBit = bestStart - *clk;
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bitnum=0;
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for (i = iii; i < *size; ++i) {
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if ((BinStream[i] >= high) && ((i-lastBit) > (*clk-tol))){
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lastBit += *clk;
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BinStream[bitnum] = *invert;
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bitnum++;
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} else if ((BinStream[i] <= low) && ((i-lastBit) > (*clk-tol))){
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//low found and we are expecting a bar
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lastBit+=*clk;
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BinStream[bitnum] = 1-*invert;
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bitnum++;
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} else {
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//mid value found or no bar supposed to be here
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if ((i-lastBit)>(*clk+tol)){
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//should have hit a high or low based on clock!!
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//debug
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//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);
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if (bitnum > 0){
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BinStream[bitnum]=77;
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bitnum++;
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}
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lastBit+=*clk;//skip over error
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}
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}
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if (bitnum >=400) break;
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}
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*size=bitnum;
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} else{
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*invert=bestStart;
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*clk=iii;
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return -1;
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}
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return bestErrCnt;
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}
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//by marshmellow
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//take 10 and 01 and manchester decode
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//run through 2 times and take least errCnt
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int manrawdecode(uint8_t * BitStream, size_t *size)
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{
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int bitnum=0;
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int errCnt =0;
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int i=1;
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int bestErr = 1000;
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int bestRun = 0;
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int ii=1;
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for (ii=1;ii<3;++ii){
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i=1;
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for (i=i+ii;i<*size-2;i+=2){
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if(BitStream[i]==1 && (BitStream[i+1]==0)){
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} else if((BitStream[i]==0)&& BitStream[i+1]==1){
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} else {
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errCnt++;
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}
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if(bitnum>300) break;
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}
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if (bestErr>errCnt){
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bestErr=errCnt;
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bestRun=ii;
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}
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errCnt=0;
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}
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errCnt=bestErr;
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if (errCnt<20){
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ii=bestRun;
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i=1;
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for (i=i+ii;i < *size-2;i+=2){
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if(BitStream[i] == 1 && (BitStream[i+1] == 0)){
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BitStream[bitnum++]=0;
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} else if((BitStream[i] == 0) && BitStream[i+1] == 1){
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BitStream[bitnum++]=1;
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} else {
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BitStream[bitnum++]=77;
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//errCnt++;
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}
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if(bitnum>300) break;
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}
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*size=bitnum;
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}
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return errCnt;
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}
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//by marshmellow
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//take 01 or 10 = 0 and 11 or 00 = 1
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int BiphaseRawDecode(uint8_t *BitStream, size_t *size, int offset, int invert)
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{
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uint8_t bitnum=0;
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uint32_t errCnt =0;
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uint32_t i;
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i=offset;
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for (;i<*size-2; i+=2){
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if((BitStream[i]==1 && BitStream[i+1]==0) || (BitStream[i]==0 && BitStream[i+1]==1)){
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BitStream[bitnum++]=1^invert;
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} else if((BitStream[i]==0 && BitStream[i+1]==0) || (BitStream[i]==1 && BitStream[i+1]==1)){
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BitStream[bitnum++]=invert;
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} else {
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BitStream[bitnum++]=77;
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errCnt++;
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}
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if(bitnum>250) break;
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}
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*size=bitnum;
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return errCnt;
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}
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//by marshmellow
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//takes 2 arguments - clock and invert both as integers
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//attempts to demodulate ask only
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//prints binary found and saves in graphbuffer for further commands
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int askrawdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert)
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{
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uint32_t i;
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// int invert=0; //invert default
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int clk2 = *clk;
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*clk=DetectASKClock(BinStream, *size, *clk); //clock default
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//uint8_t BitStream[502] = {0};
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//HACK: if clock not detected correctly - default
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if (*clk<8) *clk =64;
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if (*clk<32 && clk2==0) *clk=32;
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if (*invert != 0 && *invert != 1) *invert =0;
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uint32_t initLoopMax = 200;
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if (initLoopMax > *size) initLoopMax=*size;
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// Detect high and lows
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//25% fuzz in case highs and lows aren't clipped [marshmellow]
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int high, low, ans;
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ans = getHiLo(BinStream, initLoopMax, &high, &low, 75, 75);
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if (ans<1) return -2; //just noise
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//PrintAndLog("DEBUG - valid high: %d - valid low: %d",high,low);
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int lastBit = 0; //set first clock check
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uint32_t bitnum = 0; //output counter
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uint8_t tol = 0; //clock tolerance adjust - waves will be accepted as within the clock
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// if they fall + or - this value + clock from last valid wave
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if (*clk == 32) tol=1; //clock tolerance may not be needed anymore currently set to
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// + or - 1 but could be increased for poor waves or removed entirely
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uint32_t iii = 0;
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uint32_t gLen = *size;
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if (gLen > 500) gLen=500;
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uint8_t errCnt =0;
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uint32_t bestStart = *size;
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uint32_t bestErrCnt = (*size/1000);
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uint32_t maxErr = bestErrCnt;
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uint8_t midBit=0;
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//PrintAndLog("DEBUG - lastbit - %d",lastBit);
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//loop to find first wave that works
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for (iii=0; iii < gLen; ++iii){
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if ((BinStream[iii]>=high) || (BinStream[iii]<=low)){
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lastBit=iii-*clk;
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//loop through to see if this start location works
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for (i = iii; i < *size; ++i) {
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if ((BinStream[i] >= high) && ((i-lastBit)>(*clk-tol))){
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lastBit+=*clk;
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//BitStream[bitnum] = *invert;
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//bitnum++;
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midBit=0;
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} else if ((BinStream[i] <= low) && ((i-lastBit)>(*clk-tol))){
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//low found and we are expecting a bar
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lastBit+=*clk;
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//BitStream[bitnum] = 1- *invert;
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//bitnum++;
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midBit=0;
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} else if ((BinStream[i]<=low) && (midBit==0) && ((i-lastBit)>((*clk/2)-tol))){
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//mid bar?
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midBit=1;
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//BitStream[bitnum]= 1- *invert;
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//bitnum++;
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} else if ((BinStream[i]>=high) && (midBit==0) && ((i-lastBit)>((*clk/2)-tol))){
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//mid bar?
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midBit=1;
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//BitStream[bitnum]= *invert;
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//bitnum++;
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} else if ((i-lastBit)>((*clk/2)+tol) && (midBit==0)){
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//no mid bar found
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midBit=1;
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//BitStream[bitnum]= BitStream[bitnum-1];
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//bitnum++;
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} else {
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//mid value found or no bar supposed to be here
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if ((i-lastBit)>(*clk+tol)){
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//should have hit a high or low based on clock!!
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//debug
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//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);
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//if (bitnum > 0){
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// BitStream[bitnum]=77;
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// bitnum++;
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//}
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errCnt++;
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lastBit+=*clk;//skip over until hit too many errors
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if (errCnt > ((*size/1000))){ //allow 1 error for every 1000 samples else start over
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errCnt=0;
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// bitnum=0;//start over
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break;
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}
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}
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}
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if ((i-iii)>(500 * *clk)) break; //got enough bits
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}
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//we got more than 64 good bits and not all errors
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if ((((i-iii)/ *clk) > (64+errCnt)) && (errCnt<(*size/1000))) {
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//possible good read
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if (errCnt==0){
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bestStart=iii;
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bestErrCnt=errCnt;
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break; //great read - finish
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}
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if (errCnt<bestErrCnt){ //set this as new best run
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bestErrCnt=errCnt;
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bestStart = iii;
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}
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}
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}
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}
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if (bestErrCnt<maxErr){
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//best run is good enough - set to best run and overwrite BinStream
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iii=bestStart;
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lastBit = bestStart - *clk;
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bitnum=0;
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for (i = iii; i < *size; ++i) {
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if ((BinStream[i] >= high) && ((i-lastBit) > (*clk-tol))){
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lastBit += *clk;
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BinStream[bitnum] = *invert;
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bitnum++;
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midBit=0;
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} else if ((BinStream[i] <= low) && ((i-lastBit) > (*clk-tol))){
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//low found and we are expecting a bar
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lastBit+=*clk;
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BinStream[bitnum] = 1-*invert;
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bitnum++;
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midBit=0;
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} else if ((BinStream[i]<=low) && (midBit==0) && ((i-lastBit)>((*clk/2)-tol))){
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//mid bar?
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midBit=1;
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BinStream[bitnum] = 1 - *invert;
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bitnum++;
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} else if ((BinStream[i]>=high) && (midBit==0) && ((i-lastBit)>((*clk/2)-tol))){
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//mid bar?
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midBit=1;
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BinStream[bitnum] = *invert;
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bitnum++;
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} else if ((i-lastBit)>((*clk/2)+tol) && (midBit==0)){
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//no mid bar found
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midBit=1;
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if (bitnum!=0) BinStream[bitnum] = BinStream[bitnum-1];
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bitnum++;
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} else {
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//mid value found or no bar supposed to be here
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if ((i-lastBit)>(*clk+tol)){
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//should have hit a high or low based on clock!!
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//debug
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//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);
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if (bitnum > 0){
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BinStream[bitnum]=77;
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bitnum++;
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}
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lastBit+=*clk;//skip over error
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}
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}
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if (bitnum >=400) break;
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}
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*size=bitnum;
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} else{
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*invert=bestStart;
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*clk=iii;
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return -1;
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}
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return bestErrCnt;
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}
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//translate wave to 11111100000 (1 for each short wave 0 for each long wave)
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size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow)
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{
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uint32_t last_transition = 0;
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uint32_t idx = 1;
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//uint32_t maxVal=0;
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|
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);
|
|
}
|
|
|
|
//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;
|
|
|
|
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));
|
|
} 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;
|
|
}
|
|
// 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,
|
|
// 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++;
|
|
}
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
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)
|
|
{
|
|
static const uint8_t THRESHOLD = 129;
|
|
uint32_t idx=0;
|
|
//make sure buffer has data
|
|
if (size < 66) return -1;
|
|
//test samples are not just noise
|
|
uint8_t justNoise = 1;
|
|
for(idx=0;idx< size && justNoise ;idx++){
|
|
justNoise = dest[idx] < THRESHOLD;
|
|
}
|
|
if(justNoise) return 0;
|
|
|
|
// 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;
|
|
}
|
|
|
|
// 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
|
|
int parityTest(uint32_t bits, uint8_t bitLen, uint8_t pType)
|
|
{
|
|
uint8_t ans = 0;
|
|
for (int i = 0; i < bitLen; i++){
|
|
ans ^= ((bits >> i) & 1);
|
|
}
|
|
//PrintAndLog("DEBUG: ans: %d, ptype: %d",ans,pType);
|
|
return (ans == pType);
|
|
}
|
|
|
|
// 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)
|
|
{
|
|
static const uint8_t THRESHOLD = 123;
|
|
uint32_t idx=0;
|
|
//make sure buffer has data
|
|
if (size < 96*50) return -1;
|
|
//test samples are not just noise
|
|
uint8_t justNoise = 1;
|
|
for(idx=0; idx < size && justNoise ;idx++){
|
|
justNoise = dest[idx] < THRESHOLD;
|
|
}
|
|
if(justNoise) return -2;
|
|
|
|
// FSK demodulator
|
|
size = fskdemod(dest, size, 50, 1, 10, 8); // RF/64 and invert
|
|
if (size < 96) return -3; //did we get a good demod?
|
|
|
|
uint8_t mask[] = {0,0,0,0,0,0,0,1};
|
|
for( idx=0; idx < (size - 96); idx++) {
|
|
if ( memcmp(dest + idx, mask, sizeof(mask))==0) {
|
|
// frame marker found
|
|
//return ID start index and size
|
|
return idx;
|
|
//size should always be 96
|
|
}
|
|
}
|
|
//never found mask
|
|
return -4;
|
|
}
|
|
|
|
// by marshmellow
|
|
// FSK Demod then try to locate an Farpointe Data (pyramid) ID
|
|
int PyramiddemodFSK(uint8_t *dest, size_t size)
|
|
{
|
|
static const uint8_t THRESHOLD = 123;
|
|
uint32_t idx=0;
|
|
// size_t size2 = size;
|
|
//make sure buffer has data
|
|
if (size < 128*50) return -5;
|
|
//test samples are not just noise
|
|
uint8_t justNoise = 1;
|
|
for(idx=0; idx < size && justNoise ;idx++){
|
|
justNoise = dest[idx] < THRESHOLD;
|
|
}
|
|
if(justNoise) return -1;
|
|
|
|
// FSK demodulator
|
|
size = fskdemod(dest, size, 50, 1, 10, 8); // RF/64 and invert
|
|
if (size < 128) return -2; //did we get a good demod?
|
|
|
|
uint8_t mask[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1};
|
|
for( idx=0; idx < (size - 128); idx++) {
|
|
if ( memcmp(dest + idx, mask, sizeof(mask))==0) {
|
|
// frame marker found
|
|
return idx;
|
|
}
|
|
}
|
|
//never found mask
|
|
return -4;
|
|
}
|
|
|
|
// by marshmellow
|
|
// not perfect especially with lower clocks or VERY good antennas (heavy wave clipping)
|
|
// 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 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 < 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/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++;
|
|
}
|
|
}
|
|
//if we found no errors this is correct one - return this clock
|
|
if(errCnt==0) 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;
|
|
}
|
|
}
|
|
}
|
|
int iii=0;
|
|
int best=0;
|
|
for (iii=0; iii<8;++iii){
|
|
if (bestErr[iii]<bestErr[best]){
|
|
// 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 < 8; ++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[]={1000,1000,1000,1000,1000,1000,1000,1000,1000};
|
|
int peaksdet[]={0,0,0,0,0,0,0,0,0};
|
|
//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;
|
|
}
|
|
//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/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;
|
|
}
|
|
|
|
|
|
//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
|
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int indala26decode(uint8_t *bitStream, size_t *size, uint8_t *invert)
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{
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//26 bit 40134 format (don't know other formats)
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int i;
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int long_wait=29;//29 leading zeros in format
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int start;
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int first = 0;
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int first2 = 0;
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int bitCnt = 0;
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int ii;
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// Finding the start of a UID
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for (start = 0; start <= *size - 250; start++) {
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first = bitStream[start];
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for (i = start; i < start + long_wait; i++) {
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if (bitStream[i] != first) {
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break;
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}
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}
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if (i == (start + long_wait)) {
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break;
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}
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}
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if (start == *size - 250 + 1) {
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// did not find start sequence
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return -1;
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}
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// Inverting signal if needed
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if (first == 1) {
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for (i = start; i < *size; i++) {
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bitStream[i] = !bitStream[i];
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}
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*invert = 1;
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}else *invert=0;
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int iii;
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//found start once now test length by finding next one
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for (ii=start+29; ii <= *size - 250; ii++) {
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first2 = bitStream[ii];
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for (iii = ii; iii < ii + long_wait; iii++) {
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if (bitStream[iii] != first2) {
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break;
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}
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}
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if (iii == (ii + long_wait)) {
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break;
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}
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}
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if (ii== *size - 250 + 1){
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// did not find second start sequence
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return -2;
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}
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bitCnt=ii-start;
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// Dumping UID
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i = start;
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for (ii = 0; ii < bitCnt; ii++) {
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bitStream[ii] = bitStream[i++];
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}
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*size=bitCnt;
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return 1;
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}
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//by marshmellow - demodulate PSK1 wave or NRZ wave (both similar enough)
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//peaks switch bit (high=1 low=0) each clock cycle = 1 bit determined by last peak
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int pskNRZrawDemod(uint8_t *dest, size_t *size, int *clk, int *invert)
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{
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pskCleanWave(dest,*size);
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int clk2 = DetectpskNRZClock(dest, *size, *clk);
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*clk=clk2;
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uint32_t i;
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int high, low, ans;
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ans = getHiLo(dest, 1260, &high, &low, 75, 80); //25% fuzz on high 20% fuzz on low
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if (ans<1) return -2; //just noise
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uint32_t gLen = *size;
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//PrintAndLog("DEBUG - valid high: %d - valid low: %d",high,low);
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int lastBit = 0; //set first clock check
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uint32_t bitnum = 0; //output counter
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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
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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
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uint32_t iii = 0;
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uint8_t errCnt =0;
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uint32_t bestStart = *size;
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uint32_t maxErr = (*size/1000);
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uint32_t bestErrCnt = maxErr;
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//uint8_t midBit=0;
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uint8_t curBit=0;
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uint8_t bitHigh=0;
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uint8_t ignorewin=*clk/8;
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//PrintAndLog("DEBUG - lastbit - %d",lastBit);
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//loop to find first wave that works - align to clock
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for (iii=0; iii < gLen; ++iii){
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if ((dest[iii]>=high) || (dest[iii]<=low)){
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lastBit=iii-*clk;
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//loop through to see if this start location works
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for (i = iii; i < *size; ++i) {
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//if we found a high bar and we are at a clock bit
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if ((dest[i]>=high ) && (i>=lastBit+*clk-tol && i<=lastBit+*clk+tol)){
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bitHigh=1;
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lastBit+=*clk;
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ignorewin=*clk/8;
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bitnum++;
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//else if low bar found and we are at a clock point
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}else if ((dest[i]<=low ) && (i>=lastBit+*clk-tol && i<=lastBit+*clk+tol)){
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bitHigh=1;
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lastBit+=*clk;
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ignorewin=*clk/8;
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bitnum++;
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//else if no bars found
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}else if(dest[i] < high && dest[i] > low) {
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if (ignorewin==0){
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bitHigh=0;
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}else ignorewin--;
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//if we are past a clock point
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if (i >= lastBit+*clk+tol){ //clock val
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lastBit+=*clk;
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bitnum++;
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}
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//else if bar found but we are not at a clock bit and we did not just have a clock bit
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}else if ((dest[i]>=high || dest[i]<=low) && (i<lastBit+*clk-tol || i>lastBit+*clk+tol) && (bitHigh==0)){
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//error bar found no clock...
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errCnt++;
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}
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if (bitnum>=1000) break;
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}
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//we got more than 64 good bits and not all errors
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if ((bitnum > (64+errCnt)) && (errCnt < (maxErr))) {
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//possible good read
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if (errCnt == 0){
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bestStart = iii;
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bestErrCnt = errCnt;
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break; //great read - finish
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}
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if (errCnt < bestErrCnt){ //set this as new best run
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bestErrCnt = errCnt;
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bestStart = iii;
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}
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}
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}
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}
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if (bestErrCnt < maxErr){
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//best run is good enough set to best run and set overwrite BinStream
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iii=bestStart;
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lastBit=bestStart-*clk;
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bitnum=0;
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for (i = iii; i < *size; ++i) {
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//if we found a high bar and we are at a clock bit
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if ((dest[i] >= high ) && (i>=lastBit+*clk-tol && i<=lastBit+*clk+tol)){
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bitHigh=1;
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lastBit+=*clk;
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curBit=1-*invert;
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dest[bitnum]=curBit;
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ignorewin=*clk/8;
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bitnum++;
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//else if low bar found and we are at a clock point
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}else if ((dest[i]<=low ) && (i>=lastBit+*clk-tol && i<=lastBit+*clk+tol)){
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bitHigh=1;
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lastBit+=*clk;
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curBit=*invert;
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dest[bitnum]=curBit;
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ignorewin=*clk/8;
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bitnum++;
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//else if no bars found
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}else if(dest[i]<high && dest[i]>low) {
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if (ignorewin==0){
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bitHigh=0;
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}else ignorewin--;
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//if we are past a clock point
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if (i>=lastBit+*clk+tol){ //clock val
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lastBit+=*clk;
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dest[bitnum]=curBit;
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bitnum++;
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}
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//else if bar found but we are not at a clock bit and we did not just have a clock bit
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}else if ((dest[i]>=high || dest[i]<=low) && ((i<lastBit+*clk-tol) || (i>lastBit+*clk+tol)) && (bitHigh==0)){
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//error bar found no clock...
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bitHigh=1;
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dest[bitnum]=77;
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bitnum++;
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errCnt++;
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}
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if (bitnum >=1000) break;
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}
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*size=bitnum;
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} else{
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*size=bitnum;
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*clk=bestStart;
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return -1;
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}
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if (bitnum>16){
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*size=bitnum;
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} else return -1;
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return errCnt;
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}
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//by marshmellow
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//countFC is to detect the field clock and bit clock rates.
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//for fsk or ask not psk or nrz
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uint32_t countFC(uint8_t *BitStream, size_t size)
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{
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// get high/low thresholds
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int high, low;
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getHiLo(BitStream,10, &high, &low, 100, 100);
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// get zero crossing
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uint8_t zeroC = (high-low)/2+low;
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uint8_t clk[]={8,16,32,40,50,64,100,128};
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uint8_t fcLens[] = {0,0,0,0,0,0,0,0,0,0};
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uint16_t fcCnts[] = {0,0,0,0,0,0,0,0,0,0};
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uint8_t rfLens[] = {0,0,0,0,0,0,0,0,0,0,0};
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// uint8_t rfCnts[] = {0,0,0,0,0,0,0,0,0,0};
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uint8_t fcLensFnd = 0;
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uint8_t rfLensFnd = 0;
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uint8_t lastBit=0;
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uint8_t curBit=0;
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uint8_t lastFCcnt=0;
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uint32_t errCnt=0;
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uint32_t fcCounter = 0;
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uint32_t rfCounter = 0;
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uint8_t firstBitFnd = 0;
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int i;
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// prime i to first up transition
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for (i = 1; i < size; i++)
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if (BitStream[i]>=zeroC && BitStream[i-1]<zeroC)
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break;
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for (; i < size; i++){
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curBit = BitStream[i];
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lastBit = BitStream[i-1];
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if (lastBit<zeroC && curBit >= zeroC){
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// new up transition
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fcCounter++;
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rfCounter++;
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if (fcCounter > 3 && fcCounter < 256){
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//we've counted enough that it could be a valid field clock
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//if we had 5 and now have 9 then go back to 8 (for when we get a fc 9 instead of an 8)
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if (lastFCcnt==5 && fcCounter==9) fcCounter--;
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//if odd and not rc/5 add one (for when we get a fc 9 instead of 10)
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if ((fcCounter==9 && fcCounter & 1) || fcCounter==4) fcCounter++;
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//look for bit clock (rf/xx)
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if ((fcCounter<lastFCcnt || fcCounter>lastFCcnt)){
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//not the same size as the last wave - start of new bit sequence
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if (firstBitFnd>1){ //skip first wave change - probably not a complete bit
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for (int ii=0; ii<10; ii++){
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if (rfLens[ii]==rfCounter){
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//rfCnts[ii]++;
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rfCounter=0;
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break;
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}
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}
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if (rfCounter>0 && rfLensFnd<10){
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//PrintAndLog("DEBUG: rfCntr %d, fcCntr %d",rfCounter,fcCounter);
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//rfCnts[rfLensFnd]++;
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rfLens[rfLensFnd++]=rfCounter;
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}
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} else {
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//PrintAndLog("DEBUG i: %d",i);
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firstBitFnd++;
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}
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rfCounter=0;
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lastFCcnt=fcCounter;
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}
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// save last field clock count (fc/xx)
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// find which fcLens to save it to:
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for (int ii=0; ii<10; ii++){
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if (fcLens[ii]==fcCounter){
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fcCnts[ii]++;
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fcCounter=0;
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break;
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}
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}
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if (fcCounter>0 && fcLensFnd<10){
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//add new fc length
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//PrintAndLog("FCCntr %d",fcCounter);
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fcCnts[fcLensFnd]++;
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fcLens[fcLensFnd++]=fcCounter;
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}
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} else{
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// hmmm this should not happen often - count them
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errCnt++;
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}
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// reset counter
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fcCounter=0;
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} else {
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// count sample
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fcCounter++;
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rfCounter++;
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}
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}
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// if too many errors return errors as negative number (IS THIS NEEDED?)
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if (errCnt>100) return -1*errCnt;
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uint8_t maxCnt1=0, best1=9, best2=9, best3=9, rfHighest=10, rfHighest2=10, rfHighest3=10;
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// go through fclens and find which ones are bigest 2
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for (i=0; i<10; i++){
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// PrintAndLog("DEBUG: FC %d, Cnt %d, Errs %d, RF %d",fcLens[i],fcCnts[i],errCnt,rfLens[i]);
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// get the 3 best FC values
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if (fcCnts[i]>maxCnt1) {
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best3=best2;
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best2=best1;
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maxCnt1=fcCnts[i];
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best1=i;
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} else if(fcCnts[i]>fcCnts[best2]){
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best3=best2;
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best2=i;
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} else if(fcCnts[i]>fcCnts[best3]){
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best3=i;
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}
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//get highest 2 RF values (might need to get more values to compare or compare all?)
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if (rfLens[i]>rfLens[rfHighest]){
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rfHighest3=rfHighest2;
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rfHighest2=rfHighest;
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rfHighest=i;
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} else if(rfLens[i]>rfLens[rfHighest2]){
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rfHighest3=rfHighest2;
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rfHighest2=i;
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} else if(rfLens[i]>rfLens[rfHighest3]){
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rfHighest3=i;
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}
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}
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// set allowed clock remainder tolerance to be 1 large field clock length
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// we could have mistakenly made a 9 a 10 instead of an 8 or visa versa so rfLens could be 1 FC off
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int tol1 = (fcLens[best1]>fcLens[best2]) ? fcLens[best1] : fcLens[best2];
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// loop to find the highest clock that has a remainder less than the tolerance
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// compare samples counted divided by
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int ii=7;
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for (; ii>=0; ii--){
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if (rfLens[rfHighest] % clk[ii] < tol1 || rfLens[rfHighest] % clk[ii] > clk[ii]-tol1){
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if (rfLens[rfHighest2] % clk[ii] < tol1 || rfLens[rfHighest2] % clk[ii] > clk[ii]-tol1){
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if (rfLens[rfHighest3] % clk[ii] < tol1 || rfLens[rfHighest3] % clk[ii] > clk[ii]-tol1){
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break;
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}
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}
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}
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}
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if (ii<0) ii=7; // oops we went too far
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// TODO: take top 3 answers and compare to known Field clocks to get top 2
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uint32_t fcs=0;
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// PrintAndLog("DEBUG: Best %d best2 %d best3 %d, clk %d, clk2 %d",fcLens[best1],fcLens[best2],fcLens[best3],clk[i],clk[ii]);
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//
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if (fcLens[best1]>fcLens[best2]){
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fcs = (((uint32_t)clk[ii])<<16) | (((uint32_t)fcLens[best1])<<8) | ((fcLens[best2]));
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} else {
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fcs = (((uint32_t)clk[ii])<<16) | (((uint32_t)fcLens[best2])<<8) | ((fcLens[best1]));
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}
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return fcs;
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}
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