mirror of
https://github.com/RfidResearchGroup/proxmark3.git
synced 2024-09-21 07:46:12 +08:00
23f0a7d862
changed spacing to tabs for cmdlfem4x.c finished the partially built lf em em4x50read function added save/restore GraphBuffer function in graph.c adjusted some tolerances in lfdemod.c added a maxLen argument to the askmandemod
1607 lines
48 KiB
C
1607 lines
48 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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uint8_t justNoise(uint8_t *BitStream, size_t size)
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{
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static const uint8_t THRESHOLD = 123;
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//test samples are not just noise
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uint8_t justNoise1 = 1;
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for(size_t idx=0; idx < size && justNoise1 ;idx++){
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justNoise1 = BitStream[idx] < THRESHOLD;
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}
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return justNoise1;
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}
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//by marshmellow
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//get high and low values of a wave 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 (size_t 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 = ((*high-128)*fuzzHi + 12800)/100;
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*low = ((*low-128)*fuzzLo + 12800)/100;
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return 1;
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}
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// by marshmellow
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// pass bits to be tested in bits, length bits passed in bitLen, and parity type (even=0 | odd=1) in pType
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// returns 1 if passed
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uint8_t parityTest(uint32_t bits, uint8_t bitLen, uint8_t pType)
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{
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uint8_t ans = 0;
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for (uint8_t i = 0; i < bitLen; i++){
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ans ^= ((bits >> i) & 1);
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}
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//PrintAndLog("DEBUG: ans: %d, ptype: %d",ans,pType);
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return (ans == pType);
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}
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//by marshmellow
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//search for given preamble in given BitStream and return success=1 or fail=0 and startIndex and length
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uint8_t preambleSearch(uint8_t *BitStream, uint8_t *preamble, size_t pLen, size_t *size, size_t *startIdx)
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{
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uint8_t foundCnt=0;
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for (int idx=0; idx < *size - pLen; idx++){
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if (memcmp(BitStream+idx, preamble, pLen) == 0){
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//first index found
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foundCnt++;
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if (foundCnt == 1){
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*startIdx = idx;
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}
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if (foundCnt == 2){
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*size = idx - *startIdx;
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return 1;
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}
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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 1s and 0s and searches for EM410x format - output EM ID
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uint8_t Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx, uint32_t *hi, uint64_t *lo)
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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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uint32_t i = 0;
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if (BitStream[1]>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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// 111111111 bit pattern represent start of frame
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// include 0 in front to help get start pos
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uint8_t preamble[] = {0,1,1,1,1,1,1,1,1,1};
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uint32_t idx = 0;
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uint32_t parityBits = 0;
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uint8_t errChk = 0;
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uint8_t FmtLen = 10;
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*startIdx = 0;
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errChk = preambleSearch(BitStream, preamble, sizeof(preamble), size, startIdx);
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if (errChk == 0 || *size < 64) return 0;
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if (*size > 64) FmtLen = 22;
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*startIdx += 1; //get rid of 0 from preamble
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idx = *startIdx + 9;
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for (i=0; i<FmtLen; i++){ //loop through 10 or 22 sets of 5 bits (50-10p = 40 bits or 88 bits)
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parityBits = bytebits_to_byte(BitStream+(i*5)+idx,5);
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//check even parity - quit if failed
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if (parityTest(parityBits, 5, 0) == 0) return 0;
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//set uint64 with ID from BitStream
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for (uint8_t ii=0; ii<4; ii++){
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*hi = (*hi << 1) | (*lo >> 63);
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*lo = (*lo << 1) | (BitStream[(i*5)+ii+idx]);
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}
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}
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if (errChk != 0) return 1;
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//skip last 5 bit parity test for simplicity.
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// *size = 64 | 128;
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return 0;
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}
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// demodulates strong heavily clipped samples
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int cleanAskRawDemod(uint8_t *BinStream, size_t *size, int clk, int invert, int high, int low)
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{
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size_t bitCnt=0, smplCnt=0, errCnt=0;
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uint8_t waveHigh = 0;
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//PrintAndLog("clk: %d", clk);
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for (size_t i=0; i < *size; i++){
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if (BinStream[i] >= high && waveHigh){
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smplCnt++;
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} else if (BinStream[i] <= low && !waveHigh){
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smplCnt++;
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} else { //transition
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if ((BinStream[i] >= high && !waveHigh) || (BinStream[i] <= low && waveHigh)){
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if (smplCnt > clk-(clk/4)-1) { //full clock
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if (smplCnt > clk + (clk/4)+1) { //too many samples
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errCnt++;
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BinStream[bitCnt++]=77;
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} else if (waveHigh) {
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BinStream[bitCnt++] = invert;
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BinStream[bitCnt++] = invert;
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} else if (!waveHigh) {
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BinStream[bitCnt++] = invert ^ 1;
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BinStream[bitCnt++] = invert ^ 1;
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}
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waveHigh ^= 1;
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smplCnt = 0;
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} else if (smplCnt > (clk/2) - (clk/4)-1) {
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if (waveHigh) {
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BinStream[bitCnt++] = invert;
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} else if (!waveHigh) {
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BinStream[bitCnt++] = invert ^ 1;
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}
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waveHigh ^= 1;
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smplCnt = 0;
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} else if (!bitCnt) {
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//first bit
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waveHigh = (BinStream[i] >= high);
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smplCnt = 1;
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} else {
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smplCnt++;
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//transition bit oops
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}
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} else { //haven't hit new high or new low yet
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smplCnt++;
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}
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}
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}
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*size = bitCnt;
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return errCnt;
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}
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//by marshmellow
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//takes 3 arguments - clock, invert, maxErr 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, int maxErr)
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{
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size_t i;
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int start = DetectASKClock(BinStream, *size, clk, 20); //clock default
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if (*clk==0 || start < 0) return -3;
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if (*invert != 1) *invert=0;
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uint8_t initLoopMax = 255;
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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;
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if (getHiLo(BinStream, initLoopMax, &high, &low, 75, 75) < 1) return -2; //just noise
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// if clean clipped waves detected run alternate demod
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if (DetectCleanAskWave(BinStream, *size, high, low)) {
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cleanAskRawDemod(BinStream, size, *clk, *invert, high, low);
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return manrawdecode(BinStream, size);
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}
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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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uint16_t bitnum = 0; //output counter
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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
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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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size_t iii = 0;
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//if 0 errors allowed then only try first 2 clock cycles as we want a low tolerance
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if (!maxErr && initLoopMax > *clk*3) initLoopMax = *clk * 3;
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uint16_t errCnt = 0, MaxBits = 512;
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uint16_t bestStart = start;
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uint16_t bestErrCnt = 0;
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// PrintAndLog("DEBUG - lastbit - %d",lastBit);
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// if best start position not already found by detect clock then
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if (start <= 0 || start > initLoopMax){
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bestErrCnt = maxErr+1;
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// loop to find first wave that works
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for (iii=0; iii < initLoopMax-tol-*clk; ++iii){
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// if no peak skip
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if (BinStream[iii] < high && BinStream[iii] > low) continue;
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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 ((i-lastBit) > (*clk-tol) && (BinStream[i] >= high || BinStream[i] <= low)) {
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lastBit += *clk;
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} else if ((i-lastBit) > (*clk+tol)) {
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errCnt++;
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lastBit += *clk;
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}
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if ((i-iii) > (MaxBits * *clk) || errCnt > maxErr) break; //got plenty of bits or too many errors
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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) > (32)) && (errCnt<=maxErr)) {
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//possible good read
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if (!errCnt || errCnt < bestErrCnt){
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bestStart = iii; //set this as new best run
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bestErrCnt = errCnt;
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if (!errCnt) break; //great read - finish
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}
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}
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errCnt = 0;
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}
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}
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if (bestErrCnt > maxErr){
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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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//best run is good enough set to best run and set overwrite BinStream
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lastBit = bestStart - *clk;
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errCnt = 0;
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for (i = bestStart; i < *size; ++i) {
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if ((BinStream[i] >= high) && ((i-lastBit) > (*clk-tol))){
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//high found and we are expecting a bar
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lastBit += *clk;
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BinStream[bitnum++] = *invert;
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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++] = *invert ^ 1;
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} else if ((i-lastBit)>(*clk+tol)){
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//should have hit a high or low based on clock!!
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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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errCnt++;
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}
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lastBit += *clk;//skip over error
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}
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if (bitnum >= MaxBits) break;
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}
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*size = bitnum;
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return bestErrCnt;
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}
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//by marshmellow
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//encode binary data into binary manchester
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int ManchesterEncode(uint8_t *BitStream, size_t size)
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{
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size_t modIdx=20000, i=0;
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if (size>modIdx) return -1;
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for (size_t idx=0; idx < size; idx++){
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BitStream[idx+modIdx++] = BitStream[idx];
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BitStream[idx+modIdx++] = BitStream[idx]^1;
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}
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for (; i<(size*2); i++){
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BitStream[i] = BitStream[i+20000];
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}
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return i;
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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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uint16_t bitnum=0, MaxBits = 512, errCnt = 0;
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size_t i, ii;
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uint16_t bestErr = 1000, bestRun = 0;
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if (size == 0) return -1;
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for (ii=0;ii<2;++ii){
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for (i=ii; i<*size-2; i+=2)
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if (BitStream[i]==BitStream[i+1])
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errCnt++;
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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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for (i=bestRun; 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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}
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if(bitnum>MaxBits) break;
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}
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*size=bitnum;
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return bestErr;
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}
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//by marshmellow
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//take 01 or 10 = 1 and 11 or 00 = 0
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//check for phase errors - should never have 111 or 000 should be 01001011 or 10110100 for 1010
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//decodes biphase or if inverted it is AKA conditional dephase encoding AKA differential manchester encoding
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int BiphaseRawDecode(uint8_t *BitStream, size_t *size, int offset, int invert)
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{
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uint16_t bitnum = 0;
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uint16_t errCnt = 0;
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size_t i = offset;
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uint16_t MaxBits=512;
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//if not enough samples - error
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if (*size < 51) return -1;
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//check for phase change faults - skip one sample if faulty
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uint8_t offsetA = 1, offsetB = 1;
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for (; i<48; i+=2){
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if (BitStream[i+1]==BitStream[i+2]) offsetA=0;
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if (BitStream[i+2]==BitStream[i+3]) offsetB=0;
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}
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if (!offsetA && offsetB) offset++;
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for (i=offset; i<*size-3; i+=2){
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//check for phase error
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if (BitStream[i+1]==BitStream[i+2]) {
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BitStream[bitnum++]=77;
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errCnt++;
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}
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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>MaxBits) 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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void askAmp(uint8_t *BitStream, size_t size)
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{
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int shift = 127;
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int shiftedVal=0;
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for(size_t i = 1; i<size; i++){
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if (BitStream[i]-BitStream[i-1]>=30) //large jump up
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shift=127;
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else if(BitStream[i]-BitStream[i-1]<=-20) //large jump down
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shift=-127;
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shiftedVal=BitStream[i]+shift;
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if (shiftedVal>255)
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shiftedVal=255;
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else if (shiftedVal<0)
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shiftedVal=0;
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BitStream[i-1] = shiftedVal;
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}
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return;
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}
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//by marshmellow
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//takes 3 arguments - clock, invert and maxErr as integers
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//attempts to demodulate ask only
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int askrawdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr, uint8_t amp)
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{
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if (*size==0) return -1;
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int start = DetectASKClock(BinStream, *size, clk, 20); //clock default
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if (*clk==0 || start < 0) return -1;
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if (*invert != 1) *invert = 0;
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if (amp==1) askAmp(BinStream, *size);
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uint8_t initLoopMax = 255;
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if (initLoopMax > *size) initLoopMax=*size;
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// Detect high and lows
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//25% clip in case highs and lows aren't clipped [marshmellow]
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int high, low;
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if (getHiLo(BinStream, initLoopMax, &high, &low, 75, 75) < 1)
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return -1; //just noise
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// if clean clipped waves detected run alternate demod
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if (DetectCleanAskWave(BinStream, *size, high, low))
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return cleanAskRawDemod(BinStream, size, *clk, *invert, high, low);
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int lastBit = 0; //set first clock check - can go negative
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size_t i, iii = 0;
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size_t errCnt = 0, bitnum = 0; //output counter
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uint8_t midBit = 0;
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size_t bestStart = start, bestErrCnt = 0; //(*size/1000);
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size_t MaxBits = 1024;
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//if 0 errors allowed then only try first 2 clock cycles as we want a low tolerance
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if (!maxErr && initLoopMax > *clk*3) initLoopMax = *clk * 3;
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//if best start not already found by detectclock
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if (start <= 0 || start > initLoopMax){
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bestErrCnt = maxErr+1;
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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 < initLoopMax - *clk; ++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 (i-lastBit > *clk && (BinStream[i] >= high || BinStream[i] <= low)){
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lastBit += *clk;
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midBit = 0;
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} else if (i-lastBit > (*clk/2) && midBit == 0) {
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midBit = 1;
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} else if ((i-lastBit) > *clk) {
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//should have hit a high or low based on clock!!
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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)
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break;
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}
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if ((i-iii)>(MaxBits * *clk)) break; //got enough bits
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}
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//we got more than 32 good bits and not all errors
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if ((((i-iii)/ *clk) > 32) && (errCnt<=maxErr)) {
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//possible good read
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if (errCnt==0){
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bestStart=iii;
|
|
bestErrCnt=errCnt;
|
|
break; //great read - finish
|
|
}
|
|
if (errCnt<bestErrCnt){ //set this as new best run
|
|
bestErrCnt=errCnt;
|
|
bestStart = iii;
|
|
}
|
|
}
|
|
errCnt=0;
|
|
}
|
|
}
|
|
}
|
|
if (bestErrCnt > maxErr){
|
|
*invert = bestStart;
|
|
*clk = iii;
|
|
return -1;
|
|
}
|
|
//best run is good enough - set to best run and overwrite BinStream
|
|
lastBit = bestStart - *clk - 1;
|
|
errCnt = 0;
|
|
|
|
for (i = bestStart; i < *size; ++i) {
|
|
if (i - lastBit > *clk){
|
|
if (BinStream[i] >= high) {
|
|
BinStream[bitnum++] = *invert;
|
|
} else if (BinStream[i] <= low) {
|
|
BinStream[bitnum++] = *invert ^ 1;
|
|
} else {
|
|
if (bitnum > 0) {
|
|
BinStream[bitnum++]=77;
|
|
errCnt++;
|
|
}
|
|
}
|
|
midBit = 0;
|
|
lastBit += *clk;
|
|
} else if (i-lastBit > (*clk/2) && midBit == 0){
|
|
if (BinStream[i] >= high) {
|
|
BinStream[bitnum++] = *invert;
|
|
} else if (BinStream[i] <= low) {
|
|
BinStream[bitnum++] = *invert ^ 1;
|
|
} else {
|
|
|
|
BinStream[bitnum] = BinStream[bitnum-1];
|
|
bitnum++;
|
|
}
|
|
midBit = 1;
|
|
}
|
|
if (bitnum >= MaxBits) break;
|
|
}
|
|
*size = bitnum;
|
|
return errCnt;
|
|
}
|
|
|
|
// demod gProxIIDemod
|
|
// error returns as -x
|
|
// success returns start position in BitStream
|
|
// BitStream must contain previously askrawdemod and biphasedemoded data
|
|
int gProxII_Demod(uint8_t BitStream[], size_t *size)
|
|
{
|
|
size_t startIdx=0;
|
|
uint8_t preamble[] = {1,1,1,1,1,0};
|
|
|
|
uint8_t errChk = preambleSearch(BitStream, preamble, sizeof(preamble), size, &startIdx);
|
|
if (errChk == 0) return -3; //preamble not found
|
|
if (*size != 96) return -2; //should have found 96 bits
|
|
//check first 6 spacer bits to verify format
|
|
if (!BitStream[startIdx+5] && !BitStream[startIdx+10] && !BitStream[startIdx+15] && !BitStream[startIdx+20] && !BitStream[startIdx+25] && !BitStream[startIdx+30]){
|
|
//confirmed proper separator bits found
|
|
//return start position
|
|
return (int) startIdx;
|
|
}
|
|
return -5;
|
|
}
|
|
|
|
//translate wave to 11111100000 (1 for each short wave 0 for each long wave)
|
|
size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow)
|
|
{
|
|
size_t last_transition = 0;
|
|
size_t idx = 1;
|
|
//uint32_t maxVal=0;
|
|
if (fchigh==0) fchigh=10;
|
|
if (fclow==0) fclow=8;
|
|
//set the threshold close to 0 (graph) or 128 std to avoid static
|
|
uint8_t threshold_value = 123;
|
|
|
|
// sync to first lo-hi transition, and threshold
|
|
|
|
// Need to threshold first sample
|
|
|
|
if(dest[0] < threshold_value) dest[0] = 0;
|
|
else dest[0] = 1;
|
|
|
|
size_t numBits = 0;
|
|
// count cycles between consecutive lo-hi transitions, there should be either 8 (fc/8)
|
|
// or 10 (fc/10) cycles but in practice due to noise etc we may end up with with anywhere
|
|
// between 7 to 11 cycles so fuzz it by treat anything <9 as 8 and anything else as 10
|
|
for(idx = 1; idx < size; idx++) {
|
|
// threshold current value
|
|
|
|
if (dest[idx] < threshold_value) dest[idx] = 0;
|
|
else dest[idx] = 1;
|
|
|
|
// Check for 0->1 transition
|
|
if (dest[idx-1] < dest[idx]) { // 0 -> 1 transition
|
|
if ((idx-last_transition)<(fclow-2)){ //0-5 = garbage noise
|
|
//do nothing with extra garbage
|
|
} else if ((idx-last_transition) < (fchigh-1)) { //6-8 = 8 waves
|
|
dest[numBits++]=1;
|
|
} else if ((idx-last_transition) > (fchigh+1) && !numBits) { //12 + and first bit = garbage
|
|
//do nothing with beginning garbage
|
|
} else { //9+ = 10 waves
|
|
dest[numBits++]=0;
|
|
}
|
|
last_transition = idx;
|
|
}
|
|
}
|
|
return numBits; //Actually, it returns the number of bytes, but each byte represents a bit: 1 or 0
|
|
}
|
|
|
|
//translate 11111100000 to 10
|
|
size_t aggregate_bits(uint8_t *dest, size_t size, uint8_t rfLen,
|
|
uint8_t invert, uint8_t fchigh, uint8_t fclow)
|
|
{
|
|
uint8_t lastval=dest[0];
|
|
size_t idx=0;
|
|
size_t numBits=0;
|
|
uint32_t n=1;
|
|
for( idx=1; idx < size; idx++) {
|
|
n++;
|
|
if (dest[idx]==lastval) continue;
|
|
|
|
//if lastval was 1, we have a 1->0 crossing
|
|
if (dest[idx-1]==1) {
|
|
if (!numBits && n < rfLen/fclow) {
|
|
n=0;
|
|
lastval = dest[idx];
|
|
continue;
|
|
}
|
|
n = (n * fclow + rfLen/2) / rfLen;
|
|
} else {// 0->1 crossing
|
|
//test first bitsample too small
|
|
if (!numBits && n < rfLen/fchigh) {
|
|
n=0;
|
|
lastval = dest[idx];
|
|
continue;
|
|
}
|
|
n = (n * fchigh + rfLen/2) / rfLen;
|
|
}
|
|
if (n == 0) n = 1;
|
|
|
|
memset(dest+numBits, dest[idx-1]^invert , n);
|
|
numBits += n;
|
|
n=0;
|
|
lastval=dest[idx];
|
|
}//end for
|
|
// if valid extra bits at the end were all the same frequency - add them in
|
|
if (n > rfLen/fchigh) {
|
|
if (dest[idx-2]==1) {
|
|
n = (n * fclow + rfLen/2) / rfLen;
|
|
} else {
|
|
n = (n * fchigh + rfLen/2) / rfLen;
|
|
}
|
|
memset(dest+numBits, dest[idx-1]^invert , n);
|
|
numBits += n;
|
|
}
|
|
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, 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)
|
|
{
|
|
if (justNoise(dest, *size)) return -1;
|
|
|
|
size_t numStart=0, size2=*size, startIdx=0;
|
|
// FSK demodulator
|
|
*size = fskdemod(dest, size2,50,1,10,8); //fsk2a
|
|
if (*size < 96*2) return -2;
|
|
// 00011101 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1
|
|
uint8_t preamble[] = {0,0,0,1,1,1,0,1};
|
|
// find bitstring in array
|
|
uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
|
|
if (errChk == 0) return -3; //preamble not found
|
|
|
|
numStart = startIdx + sizeof(preamble);
|
|
// final loop, go over previously decoded FSK data and manchester decode into usable tag ID
|
|
for (size_t idx = numStart; (idx-numStart) < *size - sizeof(preamble); idx+=2){
|
|
if (dest[idx] == dest[idx+1]){
|
|
return -4; //not manchester data
|
|
}
|
|
*hi2 = (*hi2<<1)|(*hi>>31);
|
|
*hi = (*hi<<1)|(*lo>>31);
|
|
//Then, shift in a 0 or one into low
|
|
if (dest[idx] && !dest[idx+1]) // 1 0
|
|
*lo=(*lo<<1)|1;
|
|
else // 0 1
|
|
*lo=(*lo<<1)|0;
|
|
}
|
|
return (int)startIdx;
|
|
}
|
|
|
|
// loop to get raw paradox waveform then FSK demodulate the TAG ID from it
|
|
int ParadoxdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo)
|
|
{
|
|
if (justNoise(dest, *size)) return -1;
|
|
|
|
size_t numStart=0, size2=*size, startIdx=0;
|
|
// FSK demodulator
|
|
*size = fskdemod(dest, size2,50,1,10,8); //fsk2a
|
|
if (*size < 96) return -2;
|
|
|
|
// 00001111 bit pattern represent start of frame, 01 pattern represents a 0 and 10 represents a 1
|
|
uint8_t preamble[] = {0,0,0,0,1,1,1,1};
|
|
|
|
uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
|
|
if (errChk == 0) return -3; //preamble not found
|
|
|
|
numStart = startIdx + sizeof(preamble);
|
|
// final loop, go over previously decoded FSK data and manchester decode into usable tag ID
|
|
for (size_t idx = numStart; (idx-numStart) < *size - sizeof(preamble); idx+=2){
|
|
if (dest[idx] == dest[idx+1])
|
|
return -4; //not manchester data
|
|
*hi2 = (*hi2<<1)|(*hi>>31);
|
|
*hi = (*hi<<1)|(*lo>>31);
|
|
//Then, shift in a 0 or one into low
|
|
if (dest[idx] && !dest[idx+1]) // 1 0
|
|
*lo=(*lo<<1)|1;
|
|
else // 0 1
|
|
*lo=(*lo<<1)|0;
|
|
}
|
|
return (int)startIdx;
|
|
}
|
|
|
|
uint32_t bytebits_to_byte(uint8_t* src, size_t numbits)
|
|
{
|
|
uint32_t num = 0;
|
|
for(int i = 0 ; i < numbits ; i++)
|
|
{
|
|
num = (num << 1) | (*src);
|
|
src++;
|
|
}
|
|
return num;
|
|
}
|
|
|
|
int IOdemodFSK(uint8_t *dest, size_t size)
|
|
{
|
|
if (justNoise(dest, size)) return -1;
|
|
//make sure buffer has data
|
|
if (size < 66*64) return -2;
|
|
// FSK demodulator
|
|
size = fskdemod(dest, size, 64, 1, 10, 8); // FSK2a RF/64
|
|
if (size < 65) return -3; //did we get a good demod?
|
|
//Index map
|
|
//0 10 20 30 40 50 60
|
|
//| | | | | | |
|
|
//01234567 8 90123456 7 89012345 6 78901234 5 67890123 4 56789012 3 45678901 23
|
|
//-----------------------------------------------------------------------------
|
|
//00000000 0 11110000 1 facility 1 version* 1 code*one 1 code*two 1 ???????? 11
|
|
//
|
|
//XSF(version)facility:codeone+codetwo
|
|
//Handle the data
|
|
size_t startIdx = 0;
|
|
uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,1};
|
|
uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), &size, &startIdx);
|
|
if (errChk == 0) return -4; //preamble not found
|
|
|
|
if (!dest[startIdx+8] && dest[startIdx+17]==1 && dest[startIdx+26]==1 && dest[startIdx+35]==1 && dest[startIdx+44]==1 && dest[startIdx+53]==1){
|
|
//confirmed proper separator bits found
|
|
//return start position
|
|
return (int) startIdx;
|
|
}
|
|
return -5;
|
|
}
|
|
|
|
// by marshmellow
|
|
// takes a array of binary values, start position, length of bits per parity (includes parity bit),
|
|
// Parity Type (1 for odd 0 for even), and binary Length (length to run)
|
|
size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t pType, size_t bLen)
|
|
{
|
|
uint32_t parityWd = 0;
|
|
size_t j = 0, bitCnt = 0;
|
|
for (int word = 0; word < (bLen); word+=pLen){
|
|
for (int bit=0; bit < pLen; bit++){
|
|
parityWd = (parityWd << 1) | BitStream[startIdx+word+bit];
|
|
BitStream[j++] = (BitStream[startIdx+word+bit]);
|
|
}
|
|
j--;
|
|
// if parity fails then return 0
|
|
if (parityTest(parityWd, pLen, pType) == 0) return -1;
|
|
bitCnt+=(pLen-1);
|
|
parityWd = 0;
|
|
}
|
|
// if we got here then all the parities passed
|
|
//return ID start index and size
|
|
return bitCnt;
|
|
}
|
|
|
|
// by marshmellow
|
|
// FSK Demod then try to locate an AWID ID
|
|
int AWIDdemodFSK(uint8_t *dest, size_t *size)
|
|
{
|
|
//make sure buffer has enough data
|
|
if (*size < 96*50) return -1;
|
|
|
|
if (justNoise(dest, *size)) return -2;
|
|
|
|
// FSK demodulator
|
|
*size = fskdemod(dest, *size, 50, 1, 10, 8); // fsk2a RF/50
|
|
if (*size < 96) return -3; //did we get a good demod?
|
|
|
|
uint8_t preamble[] = {0,0,0,0,0,0,0,1};
|
|
size_t startIdx = 0;
|
|
uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
|
|
if (errChk == 0) return -4; //preamble not found
|
|
if (*size != 96) return -5;
|
|
return (int)startIdx;
|
|
}
|
|
|
|
// by marshmellow
|
|
// FSK Demod then try to locate an Farpointe Data (pyramid) ID
|
|
int PyramiddemodFSK(uint8_t *dest, size_t *size)
|
|
{
|
|
//make sure buffer has data
|
|
if (*size < 128*50) return -5;
|
|
|
|
//test samples are not just noise
|
|
if (justNoise(dest, *size)) return -1;
|
|
|
|
// FSK demodulator
|
|
*size = fskdemod(dest, *size, 50, 1, 10, 8); // fsk2a RF/50
|
|
if (*size < 128) return -2; //did we get a good demod?
|
|
|
|
uint8_t preamble[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1};
|
|
size_t startIdx = 0;
|
|
uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
|
|
if (errChk == 0) return -4; //preamble not found
|
|
if (*size != 128) return -3;
|
|
return (int)startIdx;
|
|
}
|
|
|
|
|
|
uint8_t DetectCleanAskWave(uint8_t dest[], size_t size, int high, int low)
|
|
{
|
|
uint16_t allPeaks=1;
|
|
uint16_t cntPeaks=0;
|
|
size_t loopEnd = 572;
|
|
if (loopEnd > size) loopEnd = size;
|
|
for (size_t i=60; i<loopEnd; i++){
|
|
if (dest[i]>low && dest[i]<high)
|
|
allPeaks=0;
|
|
else
|
|
cntPeaks++;
|
|
}
|
|
if (allPeaks == 0){
|
|
if (cntPeaks > 300) return 1;
|
|
}
|
|
return allPeaks;
|
|
}
|
|
|
|
// by marshmellow
|
|
// to help detect clocks on heavily clipped samples
|
|
// based on counts between zero crossings
|
|
int DetectStrongAskClock(uint8_t dest[], size_t size)
|
|
{
|
|
int clk[]={0,8,16,32,40,50,64,100,128};
|
|
size_t idx = 40;
|
|
uint8_t high=0;
|
|
size_t cnt = 0;
|
|
size_t highCnt = 0;
|
|
size_t highCnt2 = 0;
|
|
for (;idx < size; idx++){
|
|
if (dest[idx]>128) {
|
|
if (!high){
|
|
high=1;
|
|
if (cnt > highCnt){
|
|
if (highCnt != 0) highCnt2 = highCnt;
|
|
highCnt = cnt;
|
|
} else if (cnt > highCnt2) {
|
|
highCnt2 = cnt;
|
|
}
|
|
cnt=1;
|
|
} else {
|
|
cnt++;
|
|
}
|
|
} else if (dest[idx] <= 128){
|
|
if (high) {
|
|
high=0;
|
|
if (cnt > highCnt) {
|
|
if (highCnt != 0) highCnt2 = highCnt;
|
|
highCnt = cnt;
|
|
} else if (cnt > highCnt2) {
|
|
highCnt2 = cnt;
|
|
}
|
|
cnt=1;
|
|
} else {
|
|
cnt++;
|
|
}
|
|
}
|
|
}
|
|
uint8_t tol;
|
|
for (idx=8; idx>0; idx--){
|
|
tol = clk[idx]/8;
|
|
if (clk[idx] >= highCnt - tol && clk[idx] <= highCnt + tol)
|
|
return clk[idx];
|
|
if (clk[idx] >= highCnt2 - tol && clk[idx] <= highCnt2 + tol)
|
|
return clk[idx];
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
// 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?
|
|
// return start index of best starting position for that clock and return clock (by reference)
|
|
int DetectASKClock(uint8_t dest[], size_t size, int *clock, int maxErr)
|
|
{
|
|
size_t i=0;
|
|
uint8_t clk[]={8,16,32,40,50,64,100,128,255};
|
|
uint8_t loopCnt = 255; //don't need to loop through entire array...
|
|
if (size==0) return -1;
|
|
if (size <= loopCnt) loopCnt = size-1; //not enough samples
|
|
//if we already have a valid clock quit
|
|
|
|
for (;i<8;++i)
|
|
if (clk[i] == *clock) return 0;
|
|
|
|
//get high and low peak
|
|
int peak, low;
|
|
if (getHiLo(dest, loopCnt, &peak, &low, 75, 75) < 1) return -1;
|
|
|
|
//test for large clean peaks
|
|
if (DetectCleanAskWave(dest, size, peak, low)==1){
|
|
int ans = DetectStrongAskClock(dest, size);
|
|
for (i=7; i>0; i--){
|
|
if (clk[i] == ans) {
|
|
*clock = ans;
|
|
return 0;
|
|
}
|
|
}
|
|
}
|
|
uint8_t ii;
|
|
uint8_t clkCnt, tol = 0;
|
|
uint16_t bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000,1000};
|
|
uint8_t bestStart[]={0,0,0,0,0,0,0,0,0};
|
|
size_t errCnt = 0;
|
|
size_t arrLoc, loopEnd;
|
|
//test each valid clock from smallest to greatest to see which lines up
|
|
for(clkCnt=0; clkCnt < 8; clkCnt++){
|
|
if (clk[clkCnt] == 32){
|
|
tol=1;
|
|
}else{
|
|
tol=0;
|
|
}
|
|
if (!maxErr && loopCnt>clk[clkCnt]*2) loopCnt=clk[clkCnt]*2;
|
|
bestErr[clkCnt]=1000;
|
|
//try lining up the peaks by moving starting point (try first 256)
|
|
for (ii=0; ii < loopCnt-tol-clk[clkCnt]; ii++){
|
|
if (dest[ii] < peak && dest[ii] > low) continue;
|
|
|
|
errCnt=0;
|
|
// now that we have the first one lined up test rest of wave array
|
|
loopEnd = ((size-ii-tol) / clk[clkCnt]) - 1;
|
|
for (i=0; i < loopEnd; ++i){
|
|
arrLoc = ii + (i * clk[clkCnt]);
|
|
if (dest[arrLoc] >= peak || dest[arrLoc] <= low){
|
|
}else if (dest[arrLoc-tol] >= peak || dest[arrLoc-tol] <= low){
|
|
}else if (dest[arrLoc+tol] >= peak || dest[arrLoc+tol] <= low){
|
|
}else{ //error no peak detected
|
|
errCnt++;
|
|
}
|
|
}
|
|
//if we found no errors then we can stop here
|
|
// this is correct one - return this clock
|
|
//PrintAndLog("DEBUG: clk %d, err %d, ii %d, i %d",clk[clkCnt],errCnt,ii,i);
|
|
if(errCnt==0 && clkCnt<6) {
|
|
*clock = clk[clkCnt];
|
|
return ii;
|
|
}
|
|
//if we found errors see if it is lowest so far and save it as best run
|
|
if(errCnt<bestErr[clkCnt]){
|
|
bestErr[clkCnt]=errCnt;
|
|
bestStart[clkCnt]=ii;
|
|
}
|
|
}
|
|
}
|
|
uint8_t iii=0;
|
|
uint8_t best=0;
|
|
for (iii=0; iii<8; ++iii){
|
|
if (bestErr[iii] < bestErr[best]){
|
|
if (bestErr[iii] == 0) bestErr[iii]=1;
|
|
// current best bit to error ratio vs new bit to error ratio
|
|
if ( (size/clk[best])/bestErr[best] < (size/clk[iii])/bestErr[iii] ){
|
|
best = iii;
|
|
}
|
|
}
|
|
}
|
|
if (bestErr[best] > maxErr) return -1;
|
|
*clock = clk[best];
|
|
return bestStart[best];
|
|
}
|
|
|
|
//by marshmellow
|
|
//detect psk clock by reading each phase shift
|
|
// a phase shift is determined by measuring the sample length of each wave
|
|
int DetectPSKClock(uint8_t dest[], size_t size, int clock)
|
|
{
|
|
uint8_t clk[]={255,16,32,40,50,64,100,128,255}; //255 is not a valid clock
|
|
uint16_t loopCnt = 4096; //don't need to loop through entire array...
|
|
if (size == 0) return 0;
|
|
if (size<loopCnt) loopCnt = size;
|
|
|
|
//if we already have a valid clock quit
|
|
size_t i=1;
|
|
for (; i < 8; ++i)
|
|
if (clk[i] == clock) return clock;
|
|
|
|
size_t waveStart=0, waveEnd=0, firstFullWave=0, lastClkBit=0;
|
|
uint8_t clkCnt, fc=0, fullWaveLen=0, tol=1;
|
|
uint16_t peakcnt=0, errCnt=0, waveLenCnt=0;
|
|
uint16_t bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000,1000};
|
|
uint16_t peaksdet[]={0,0,0,0,0,0,0,0,0};
|
|
fc = countFC(dest, size, 0);
|
|
if (fc!=2 && fc!=4 && fc!=8) return -1;
|
|
//PrintAndLog("DEBUG: FC: %d",fc);
|
|
|
|
//find first full wave
|
|
for (i=0; i<loopCnt; i++){
|
|
if (dest[i] < dest[i+1] && dest[i+1] >= dest[i+2]){
|
|
if (waveStart == 0) {
|
|
waveStart = i+1;
|
|
//PrintAndLog("DEBUG: waveStart: %d",waveStart);
|
|
} else {
|
|
waveEnd = i+1;
|
|
//PrintAndLog("DEBUG: waveEnd: %d",waveEnd);
|
|
waveLenCnt = waveEnd-waveStart;
|
|
if (waveLenCnt > fc){
|
|
firstFullWave = waveStart;
|
|
fullWaveLen=waveLenCnt;
|
|
break;
|
|
}
|
|
waveStart=0;
|
|
}
|
|
}
|
|
}
|
|
//PrintAndLog("DEBUG: firstFullWave: %d, waveLen: %d",firstFullWave,fullWaveLen);
|
|
|
|
//test each valid clock from greatest to smallest to see which lines up
|
|
for(clkCnt=7; clkCnt >= 1 ; clkCnt--){
|
|
lastClkBit = firstFullWave; //set end of wave as clock align
|
|
waveStart = 0;
|
|
errCnt=0;
|
|
peakcnt=0;
|
|
//PrintAndLog("DEBUG: clk: %d, lastClkBit: %d",clk[clkCnt],lastClkBit);
|
|
|
|
for (i = firstFullWave+fullWaveLen-1; i < loopCnt-2; i++){
|
|
//top edge of wave = start of new wave
|
|
if (dest[i] < dest[i+1] && dest[i+1] >= dest[i+2]){
|
|
if (waveStart == 0) {
|
|
waveStart = i+1;
|
|
waveLenCnt=0;
|
|
} else { //waveEnd
|
|
waveEnd = i+1;
|
|
waveLenCnt = waveEnd-waveStart;
|
|
if (waveLenCnt > fc){
|
|
//if this wave is a phase shift
|
|
//PrintAndLog("DEBUG: phase shift at: %d, len: %d, nextClk: %d, ii: %d, fc: %d",waveStart,waveLenCnt,lastClkBit+clk[clkCnt]-tol,ii+1,fc);
|
|
if (i+1 >= lastClkBit + clk[clkCnt] - tol){ //should be a clock bit
|
|
peakcnt++;
|
|
lastClkBit+=clk[clkCnt];
|
|
} else if (i<lastClkBit+8){
|
|
//noise after a phase shift - ignore
|
|
} else { //phase shift before supposed to based on clock
|
|
errCnt++;
|
|
}
|
|
} else if (i+1 > lastClkBit + clk[clkCnt] + tol + fc){
|
|
lastClkBit+=clk[clkCnt]; //no phase shift but clock bit
|
|
}
|
|
waveStart=i+1;
|
|
}
|
|
}
|
|
}
|
|
if (errCnt == 0){
|
|
return clk[clkCnt];
|
|
}
|
|
if (errCnt <= bestErr[clkCnt]) bestErr[clkCnt]=errCnt;
|
|
if (peakcnt > peaksdet[clkCnt]) peaksdet[clkCnt]=peakcnt;
|
|
}
|
|
//all tested with errors
|
|
//return the highest clk with the most peaks found
|
|
uint8_t best=7;
|
|
for (i=7; i>=1; i--){
|
|
if (peaksdet[i] > peaksdet[best]) {
|
|
best = i;
|
|
}
|
|
//PrintAndLog("DEBUG: Clk: %d, peaks: %d, errs: %d, bestClk: %d",clk[iii],peaksdet[iii],bestErr[iii],clk[best]);
|
|
}
|
|
return clk[best];
|
|
}
|
|
|
|
//by marshmellow
|
|
//detect nrz clock by reading #peaks vs no peaks(or errors)
|
|
int DetectNRZClock(uint8_t dest[], size_t size, int clock)
|
|
{
|
|
size_t i=0;
|
|
uint8_t clk[]={8,16,32,40,50,64,100,128,255};
|
|
size_t loopCnt = 4096; //don't need to loop through entire array...
|
|
if (size == 0) return 0;
|
|
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;
|
|
if (getHiLo(dest, loopCnt, &peak, &low, 75, 75) < 1) return 0;
|
|
|
|
//PrintAndLog("DEBUG: peak: %d, low: %d",peak,low);
|
|
size_t ii;
|
|
uint8_t clkCnt;
|
|
uint8_t tol = 0;
|
|
uint16_t peakcnt=0;
|
|
uint16_t peaksdet[]={0,0,0,0,0,0,0,0};
|
|
uint16_t maxPeak=0;
|
|
//test for large clipped waves
|
|
for (i=0; i<loopCnt; i++){
|
|
if (dest[i] >= peak || dest[i] <= low){
|
|
peakcnt++;
|
|
} else {
|
|
if (peakcnt>0 && maxPeak < peakcnt){
|
|
maxPeak = peakcnt;
|
|
}
|
|
peakcnt=0;
|
|
}
|
|
}
|
|
peakcnt=0;
|
|
//test each valid clock from smallest to greatest to see which lines up
|
|
for(clkCnt=0; clkCnt < 8; ++clkCnt){
|
|
//ignore clocks smaller than largest peak
|
|
if (clk[clkCnt]<maxPeak) continue;
|
|
|
|
//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)){
|
|
peakcnt=0;
|
|
// now that we have the first one lined up test rest of wave array
|
|
for (i=0; i < ((int)((size-ii-tol)/clk[clkCnt])-1); ++i){
|
|
if (dest[ii+(i*clk[clkCnt])]>=peak || dest[ii+(i*clk[clkCnt])]<=low){
|
|
peakcnt++;
|
|
}
|
|
}
|
|
if(peakcnt>peaksdet[clkCnt]) {
|
|
peaksdet[clkCnt]=peakcnt;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
int iii=7;
|
|
uint8_t best=0;
|
|
for (iii=7; iii > 0; iii--){
|
|
if (peaksdet[iii] > peaksdet[best]){
|
|
best = iii;
|
|
}
|
|
//PrintAndLog("DEBUG: Clk: %d, peaks: %d, errs: %d, bestClk: %d",clk[iii],peaksdet[iii],bestErr[iii],clk[best]);
|
|
}
|
|
return clk[best];
|
|
}
|
|
|
|
// by marshmellow
|
|
// convert psk1 demod to psk2 demod
|
|
// only transition waves are 1s
|
|
void psk1TOpsk2(uint8_t *BitStream, size_t size)
|
|
{
|
|
size_t i=1;
|
|
uint8_t lastBit=BitStream[0];
|
|
for (; i<size; i++){
|
|
if (BitStream[i]==77){
|
|
//ignore errors
|
|
} else if (lastBit!=BitStream[i]){
|
|
lastBit=BitStream[i];
|
|
BitStream[i]=1;
|
|
} else {
|
|
BitStream[i]=0;
|
|
}
|
|
}
|
|
return;
|
|
}
|
|
|
|
// by marshmellow
|
|
// convert psk2 demod to psk1 demod
|
|
// from only transition waves are 1s to phase shifts change bit
|
|
void psk2TOpsk1(uint8_t *BitStream, size_t size)
|
|
{
|
|
uint8_t phase=0;
|
|
for (size_t i=0; i<size; i++){
|
|
if (BitStream[i]==1){
|
|
phase ^=1;
|
|
}
|
|
BitStream[i]=phase;
|
|
}
|
|
return;
|
|
}
|
|
|
|
// redesigned by marshmellow adjusted from existing decode functions
|
|
// indala id decoding - only tested on 26 bit tags, but attempted to make it work for more
|
|
int indala26decode(uint8_t *bitStream, size_t *size, uint8_t *invert)
|
|
{
|
|
//26 bit 40134 format (don't know other formats)
|
|
int i;
|
|
int long_wait=29;//29 leading zeros in format
|
|
int start;
|
|
int first = 0;
|
|
int first2 = 0;
|
|
int bitCnt = 0;
|
|
int ii;
|
|
// Finding the start of a UID
|
|
for (start = 0; start <= *size - 250; start++) {
|
|
first = bitStream[start];
|
|
for (i = start; i < start + long_wait; i++) {
|
|
if (bitStream[i] != first) {
|
|
break;
|
|
}
|
|
}
|
|
if (i == (start + long_wait)) {
|
|
break;
|
|
}
|
|
}
|
|
if (start == *size - 250 + 1) {
|
|
// did not find start sequence
|
|
return -1;
|
|
}
|
|
// Inverting signal if needed
|
|
if (first == 1) {
|
|
for (i = start; i < *size; i++) {
|
|
bitStream[i] = !bitStream[i];
|
|
}
|
|
*invert = 1;
|
|
}else *invert=0;
|
|
|
|
int iii;
|
|
//found start once now test length by finding next one
|
|
for (ii=start+29; ii <= *size - 250; ii++) {
|
|
first2 = bitStream[ii];
|
|
for (iii = ii; iii < ii + long_wait; iii++) {
|
|
if (bitStream[iii] != first2) {
|
|
break;
|
|
}
|
|
}
|
|
if (iii == (ii + long_wait)) {
|
|
break;
|
|
}
|
|
}
|
|
if (ii== *size - 250 + 1){
|
|
// did not find second start sequence
|
|
return -2;
|
|
}
|
|
bitCnt=ii-start;
|
|
|
|
// Dumping UID
|
|
i = start;
|
|
for (ii = 0; ii < bitCnt; ii++) {
|
|
bitStream[ii] = bitStream[i++];
|
|
}
|
|
*size=bitCnt;
|
|
return 1;
|
|
}
|
|
|
|
// by marshmellow - demodulate NRZ wave (both similar enough)
|
|
// peaks invert bit (high=1 low=0) each clock cycle = 1 bit determined by last peak
|
|
// there probably is a much simpler way to do this....
|
|
int nrzRawDemod(uint8_t *dest, size_t *size, int *clk, int *invert, int maxErr)
|
|
{
|
|
if (justNoise(dest, *size)) return -1;
|
|
*clk = DetectNRZClock(dest, *size, *clk);
|
|
if (*clk==0) return -2;
|
|
size_t i, gLen = 4096;
|
|
if (gLen>*size) gLen = *size;
|
|
int high, low;
|
|
if (getHiLo(dest, gLen, &high, &low, 75, 75) < 1) return -3; //25% fuzz on high 25% fuzz on low
|
|
int lastBit = 0; //set first clock check
|
|
size_t iii = 0, bitnum = 0; //bitnum counter
|
|
uint16_t errCnt = 0, MaxBits = 1000;
|
|
size_t bestErrCnt = maxErr+1;
|
|
size_t bestPeakCnt = 0, bestPeakStart = 0;
|
|
uint8_t bestFirstPeakHigh=0, firstPeakHigh=0, curBit=0, bitHigh=0, errBitHigh=0;
|
|
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
|
|
uint16_t peakCnt=0;
|
|
uint8_t ignoreWindow=4;
|
|
uint8_t ignoreCnt=ignoreWindow; //in case of noise near peak
|
|
//loop to find first wave that works - align to clock
|
|
for (iii=0; iii < gLen; ++iii){
|
|
if ((dest[iii]>=high) || (dest[iii]<=low)){
|
|
if (dest[iii]>=high) firstPeakHigh=1;
|
|
else firstPeakHigh=0;
|
|
lastBit=iii-*clk;
|
|
peakCnt=0;
|
|
errCnt=0;
|
|
//loop through to see if this start location works
|
|
for (i = iii; i < *size; ++i) {
|
|
// if we are at a clock bit
|
|
if ((i >= lastBit + *clk - tol) && (i <= lastBit + *clk + tol)) {
|
|
//test high/low
|
|
if (dest[i] >= high || dest[i] <= low) {
|
|
bitHigh = 1;
|
|
peakCnt++;
|
|
errBitHigh = 0;
|
|
ignoreCnt = ignoreWindow;
|
|
lastBit += *clk;
|
|
} else if (i == lastBit + *clk + tol) {
|
|
lastBit += *clk;
|
|
}
|
|
//else if no bars found
|
|
} else if (dest[i] < high && dest[i] > low){
|
|
if (ignoreCnt==0){
|
|
bitHigh=0;
|
|
if (errBitHigh==1) errCnt++;
|
|
errBitHigh=0;
|
|
} else {
|
|
ignoreCnt--;
|
|
}
|
|
} else if ((dest[i]>=high || dest[i]<=low) && (bitHigh==0)) {
|
|
//error bar found no clock...
|
|
errBitHigh=1;
|
|
}
|
|
if (((i-iii) / *clk)>=MaxBits) break;
|
|
}
|
|
//we got more than 64 good bits and not all errors
|
|
if (((i-iii) / *clk) > 64 && (errCnt <= (maxErr))) {
|
|
//possible good read
|
|
if (!errCnt || peakCnt > bestPeakCnt){
|
|
bestFirstPeakHigh=firstPeakHigh;
|
|
bestErrCnt = errCnt;
|
|
bestPeakCnt = peakCnt;
|
|
bestPeakStart = iii;
|
|
if (!errCnt) break; //great read - finish
|
|
}
|
|
}
|
|
}
|
|
}
|
|
//PrintAndLog("DEBUG: bestErrCnt: %d, maxErr: %d, bestStart: %d, bestPeakCnt: %d, bestPeakStart: %d",bestErrCnt,maxErr,bestStart,bestPeakCnt,bestPeakStart);
|
|
if (bestErrCnt > maxErr) return bestErrCnt;
|
|
|
|
//best run is good enough set to best run and set overwrite BinStream
|
|
lastBit = bestPeakStart - *clk;
|
|
memset(dest, bestFirstPeakHigh^1, bestPeakStart / *clk);
|
|
bitnum += (bestPeakStart / *clk);
|
|
for (i = bestPeakStart; i < *size; ++i) {
|
|
// if expecting a clock bit
|
|
if ((i >= lastBit + *clk - tol) && (i <= lastBit + *clk + tol)) {
|
|
// test high/low
|
|
if (dest[i] >= high || dest[i] <= low) {
|
|
peakCnt++;
|
|
bitHigh = 1;
|
|
errBitHigh = 0;
|
|
ignoreCnt = ignoreWindow;
|
|
curBit = *invert;
|
|
if (dest[i] >= high) curBit ^= 1;
|
|
dest[bitnum++] = curBit;
|
|
lastBit += *clk;
|
|
//else no bars found in clock area
|
|
} else if (i == lastBit + *clk + tol) {
|
|
dest[bitnum++] = curBit;
|
|
lastBit += *clk;
|
|
}
|
|
//else if no bars found
|
|
} else if (dest[i] < high && dest[i] > low){
|
|
if (ignoreCnt == 0){
|
|
bitHigh = 0;
|
|
if (errBitHigh == 1){
|
|
dest[bitnum++] = 77;
|
|
errCnt++;
|
|
}
|
|
errBitHigh=0;
|
|
} else {
|
|
ignoreCnt--;
|
|
}
|
|
} else if ((dest[i] >= high || dest[i] <= low) && (bitHigh == 0)) {
|
|
//error bar found no clock...
|
|
errBitHigh=1;
|
|
}
|
|
if (bitnum >= MaxBits) break;
|
|
}
|
|
*size = bitnum;
|
|
return bestErrCnt;
|
|
}
|
|
|
|
//by marshmellow
|
|
//detects the bit clock for FSK given the high and low Field Clocks
|
|
uint8_t detectFSKClk(uint8_t *BitStream, size_t size, uint8_t fcHigh, uint8_t fcLow)
|
|
{
|
|
uint8_t clk[] = {8,16,32,40,50,64,100,128,0};
|
|
uint16_t rfLens[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
|
|
uint8_t rfCnts[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
|
|
uint8_t rfLensFnd = 0;
|
|
uint8_t lastFCcnt = 0;
|
|
uint16_t fcCounter = 0;
|
|
uint16_t rfCounter = 0;
|
|
uint8_t firstBitFnd = 0;
|
|
size_t i;
|
|
if (size == 0) return 0;
|
|
|
|
uint8_t fcTol = (uint8_t)(0.5+(float)(fcHigh-fcLow)/2);
|
|
rfLensFnd=0;
|
|
fcCounter=0;
|
|
rfCounter=0;
|
|
firstBitFnd=0;
|
|
//PrintAndLog("DEBUG: fcTol: %d",fcTol);
|
|
// prime i to first up transition
|
|
for (i = 1; i < size-1; i++)
|
|
if (BitStream[i] > BitStream[i-1] && BitStream[i]>=BitStream[i+1])
|
|
break;
|
|
|
|
for (; i < size-1; i++){
|
|
fcCounter++;
|
|
rfCounter++;
|
|
|
|
if (BitStream[i] <= BitStream[i-1] || BitStream[i] < BitStream[i+1])
|
|
continue;
|
|
// else new peak
|
|
// if we got less than the small fc + tolerance then set it to the small fc
|
|
if (fcCounter < fcLow+fcTol)
|
|
fcCounter = fcLow;
|
|
else //set it to the large fc
|
|
fcCounter = fcHigh;
|
|
|
|
//look for bit clock (rf/xx)
|
|
if ((fcCounter < lastFCcnt || fcCounter > lastFCcnt)){
|
|
//not the same size as the last wave - start of new bit sequence
|
|
if (firstBitFnd > 1){ //skip first wave change - probably not a complete bit
|
|
for (int ii=0; ii<15; ii++){
|
|
if (rfLens[ii] == rfCounter){
|
|
rfCnts[ii]++;
|
|
rfCounter = 0;
|
|
break;
|
|
}
|
|
}
|
|
if (rfCounter > 0 && rfLensFnd < 15){
|
|
//PrintAndLog("DEBUG: rfCntr %d, fcCntr %d",rfCounter,fcCounter);
|
|
rfCnts[rfLensFnd]++;
|
|
rfLens[rfLensFnd++] = rfCounter;
|
|
}
|
|
} else {
|
|
firstBitFnd++;
|
|
}
|
|
rfCounter=0;
|
|
lastFCcnt=fcCounter;
|
|
}
|
|
fcCounter=0;
|
|
}
|
|
uint8_t rfHighest=15, rfHighest2=15, rfHighest3=15;
|
|
|
|
for (i=0; i<15; i++){
|
|
//PrintAndLog("DEBUG: RF %d, cnts %d",rfLens[i], rfCnts[i]);
|
|
//get highest 2 RF values (might need to get more values to compare or compare all?)
|
|
if (rfCnts[i]>rfCnts[rfHighest]){
|
|
rfHighest3=rfHighest2;
|
|
rfHighest2=rfHighest;
|
|
rfHighest=i;
|
|
} else if(rfCnts[i]>rfCnts[rfHighest2]){
|
|
rfHighest3=rfHighest2;
|
|
rfHighest2=i;
|
|
} else if(rfCnts[i]>rfCnts[rfHighest3]){
|
|
rfHighest3=i;
|
|
}
|
|
}
|
|
// set allowed clock remainder tolerance to be 1 large field clock length+1
|
|
// we could have mistakenly made a 9 a 10 instead of an 8 or visa versa so rfLens could be 1 FC off
|
|
uint8_t tol1 = fcHigh+1;
|
|
|
|
//PrintAndLog("DEBUG: hightest: 1 %d, 2 %d, 3 %d",rfLens[rfHighest],rfLens[rfHighest2],rfLens[rfHighest3]);
|
|
|
|
// loop to find the highest clock that has a remainder less than the tolerance
|
|
// compare samples counted divided by
|
|
int ii=7;
|
|
for (; ii>=0; ii--){
|
|
if (rfLens[rfHighest] % clk[ii] < tol1 || rfLens[rfHighest] % clk[ii] > clk[ii]-tol1){
|
|
if (rfLens[rfHighest2] % clk[ii] < tol1 || rfLens[rfHighest2] % clk[ii] > clk[ii]-tol1){
|
|
if (rfLens[rfHighest3] % clk[ii] < tol1 || rfLens[rfHighest3] % clk[ii] > clk[ii]-tol1){
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
if (ii<0) return 0; // oops we went too far
|
|
|
|
return clk[ii];
|
|
}
|
|
|
|
//by marshmellow
|
|
//countFC is to detect the field clock lengths.
|
|
//counts and returns the 2 most common wave lengths
|
|
//mainly used for FSK field clock detection
|
|
uint16_t countFC(uint8_t *BitStream, size_t size, uint8_t fskAdj)
|
|
{
|
|
uint8_t fcLens[] = {0,0,0,0,0,0,0,0,0,0};
|
|
uint16_t fcCnts[] = {0,0,0,0,0,0,0,0,0,0};
|
|
uint8_t fcLensFnd = 0;
|
|
uint8_t lastFCcnt=0;
|
|
uint8_t fcCounter = 0;
|
|
size_t i;
|
|
if (size == 0) return 0;
|
|
|
|
// prime i to first up transition
|
|
for (i = 1; i < size-1; i++)
|
|
if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1])
|
|
break;
|
|
|
|
for (; i < size-1; i++){
|
|
if (BitStream[i] > BitStream[i-1] && BitStream[i] >= BitStream[i+1]){
|
|
// new up transition
|
|
fcCounter++;
|
|
if (fskAdj){
|
|
//if we had 5 and now have 9 then go back to 8 (for when we get a fc 9 instead of an 8)
|
|
if (lastFCcnt==5 && fcCounter==9) fcCounter--;
|
|
//if fc=9 or 4 add one (for when we get a fc 9 instead of 10 or a 4 instead of a 5)
|
|
if ((fcCounter==9) || fcCounter==4) fcCounter++;
|
|
// save last field clock count (fc/xx)
|
|
lastFCcnt = fcCounter;
|
|
}
|
|
// find which fcLens to save it to:
|
|
for (int ii=0; ii<10; ii++){
|
|
if (fcLens[ii]==fcCounter){
|
|
fcCnts[ii]++;
|
|
fcCounter=0;
|
|
break;
|
|
}
|
|
}
|
|
if (fcCounter>0 && fcLensFnd<10){
|
|
//add new fc length
|
|
fcCnts[fcLensFnd]++;
|
|
fcLens[fcLensFnd++]=fcCounter;
|
|
}
|
|
fcCounter=0;
|
|
} else {
|
|
// count sample
|
|
fcCounter++;
|
|
}
|
|
}
|
|
|
|
uint8_t best1=9, best2=9, best3=9;
|
|
uint16_t maxCnt1=0;
|
|
// go through fclens and find which ones are bigest 2
|
|
for (i=0; i<10; i++){
|
|
// PrintAndLog("DEBUG: FC %d, Cnt %d, Errs %d",fcLens[i],fcCnts[i],errCnt);
|
|
// get the 3 best FC values
|
|
if (fcCnts[i]>maxCnt1) {
|
|
best3=best2;
|
|
best2=best1;
|
|
maxCnt1=fcCnts[i];
|
|
best1=i;
|
|
} else if(fcCnts[i]>fcCnts[best2]){
|
|
best3=best2;
|
|
best2=i;
|
|
} else if(fcCnts[i]>fcCnts[best3]){
|
|
best3=i;
|
|
}
|
|
}
|
|
uint8_t fcH=0, fcL=0;
|
|
if (fcLens[best1]>fcLens[best2]){
|
|
fcH=fcLens[best1];
|
|
fcL=fcLens[best2];
|
|
} else{
|
|
fcH=fcLens[best2];
|
|
fcL=fcLens[best1];
|
|
}
|
|
|
|
// TODO: take top 3 answers and compare to known Field clocks to get top 2
|
|
|
|
uint16_t fcs = (((uint16_t)fcH)<<8) | fcL;
|
|
// PrintAndLog("DEBUG: Best %d best2 %d best3 %d",fcLens[best1],fcLens[best2],fcLens[best3]);
|
|
if (fskAdj) return fcs;
|
|
return fcLens[best1];
|
|
}
|
|
|
|
//by marshmellow - demodulate PSK1 wave
|
|
//uses wave lengths (# Samples)
|
|
int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert)
|
|
{
|
|
if (size == 0) return -1;
|
|
uint16_t loopCnt = 4096; //don't need to loop through entire array...
|
|
if (*size<loopCnt) loopCnt = *size;
|
|
|
|
uint8_t curPhase = *invert;
|
|
size_t i, waveStart=1, waveEnd=0, firstFullWave=0, lastClkBit=0;
|
|
uint8_t fc=0, fullWaveLen=0, tol=1;
|
|
uint16_t errCnt=0, waveLenCnt=0;
|
|
fc = countFC(dest, *size, 0);
|
|
if (fc!=2 && fc!=4 && fc!=8) return -1;
|
|
//PrintAndLog("DEBUG: FC: %d",fc);
|
|
*clock = DetectPSKClock(dest, *size, *clock);
|
|
if (*clock == 0) return -1;
|
|
int avgWaveVal=0, lastAvgWaveVal=0;
|
|
//find first phase shift
|
|
for (i=0; i<loopCnt; i++){
|
|
if (dest[i]+fc < dest[i+1] && dest[i+1] >= dest[i+2]){
|
|
waveEnd = i+1;
|
|
//PrintAndLog("DEBUG: waveEnd: %d",waveEnd);
|
|
waveLenCnt = waveEnd-waveStart;
|
|
if (waveLenCnt > fc && waveStart > fc){ //not first peak and is a large wave
|
|
lastAvgWaveVal = avgWaveVal/(waveLenCnt);
|
|
firstFullWave = waveStart;
|
|
fullWaveLen=waveLenCnt;
|
|
//if average wave value is > graph 0 then it is an up wave or a 1
|
|
if (lastAvgWaveVal > 123) curPhase ^= 1; //fudge graph 0 a little 123 vs 128
|
|
break;
|
|
}
|
|
waveStart = i+1;
|
|
avgWaveVal = 0;
|
|
}
|
|
avgWaveVal += dest[i+2];
|
|
}
|
|
//PrintAndLog("DEBUG: firstFullWave: %d, waveLen: %d",firstFullWave,fullWaveLen);
|
|
lastClkBit = firstFullWave; //set start of wave as clock align
|
|
//PrintAndLog("DEBUG: clk: %d, lastClkBit: %d", *clock, lastClkBit);
|
|
waveStart = 0;
|
|
size_t numBits=0;
|
|
//set skipped bits
|
|
memset(dest, curPhase^1, firstFullWave / *clock);
|
|
numBits += (firstFullWave / *clock);
|
|
dest[numBits++] = curPhase; //set first read bit
|
|
for (i = firstFullWave + fullWaveLen - 1; i < *size-3; i++){
|
|
//top edge of wave = start of new wave
|
|
if (dest[i]+fc < dest[i+1] && dest[i+1] >= dest[i+2]){
|
|
if (waveStart == 0) {
|
|
waveStart = i+1;
|
|
waveLenCnt = 0;
|
|
avgWaveVal = dest[i+1];
|
|
} else { //waveEnd
|
|
waveEnd = i+1;
|
|
waveLenCnt = waveEnd-waveStart;
|
|
lastAvgWaveVal = avgWaveVal/waveLenCnt;
|
|
if (waveLenCnt > fc){
|
|
//PrintAndLog("DEBUG: avgWaveVal: %d, waveSum: %d",lastAvgWaveVal,avgWaveVal);
|
|
//this wave is a phase shift
|
|
//PrintAndLog("DEBUG: phase shift at: %d, len: %d, nextClk: %d, i: %d, fc: %d",waveStart,waveLenCnt,lastClkBit+*clock-tol,i+1,fc);
|
|
if (i+1 >= lastClkBit + *clock - tol){ //should be a clock bit
|
|
curPhase ^= 1;
|
|
dest[numBits++] = curPhase;
|
|
lastClkBit += *clock;
|
|
} else if (i < lastClkBit+10+fc){
|
|
//noise after a phase shift - ignore
|
|
} else { //phase shift before supposed to based on clock
|
|
errCnt++;
|
|
dest[numBits++] = 77;
|
|
}
|
|
} else if (i+1 > lastClkBit + *clock + tol + fc){
|
|
lastClkBit += *clock; //no phase shift but clock bit
|
|
dest[numBits++] = curPhase;
|
|
}
|
|
avgWaveVal = 0;
|
|
waveStart = i+1;
|
|
}
|
|
}
|
|
avgWaveVal += dest[i+1];
|
|
}
|
|
*size = numBits;
|
|
return errCnt;
|
|
}
|