lf cleaning

[proxmark3-svn] / common / lfdemod.c

diff --git a/common/lfdemod.c b/common/lfdemod.c
index c00222b3b69ca23a277f041a027c14a02d2e0feb..58221546b24da9ce67c6aa60495f325d6a911ec1 100644 (file)
--- a/common/lfdemod.c
+++ b/common/lfdemod.c
@@ -81,10 +81,8 @@ uint8_t Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx, uint32_
        //  otherwise could be a void with no arguments
        //set defaults
        uint32_t i = 0;
-       if (BitStream[1]>1){  //allow only 1s and 0s
-               // PrintAndLog("no data found");
-               return 0;
-       }
+       if (BitStream[1]>1) return 0;  //allow only 1s and 0s
+
        // 111111111 bit pattern represent start of frame
        //  include 0 in front to help get start pos
        uint8_t preamble[] = {0,1,1,1,1,1,1,1,1,1};
@@ -130,7 +128,7 @@ int cleanAskRawDemod(uint8_t *BinStream, size_t *size, int clk, int invert, int
                                if (smplCnt > clk-(clk/4)-1) { //full clock
                                        if (smplCnt > clk + (clk/4)+1) { //too many samples
                                                errCnt++;
-                                               BinStream[bitCnt++]=77;
+                                               BinStream[bitCnt++]=7;
                                        } else if (waveHigh) {
                                                BinStream[bitCnt++] = invert;
                                                BinStream[bitCnt++] = invert;
@@ -208,7 +206,7 @@ int askmandemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int max
                        //should have hit a high or low based on clock!!
                        //PrintAndLog("DEBUG - no wave in expected area - location: %d, expected: %d-%d, lastBit: %d - resetting search",i,(lastBit+(clk-((int)(tol)))),(lastBit+(clk+((int)(tol)))),lastBit);
                        if (bitnum > 0) {
-                               BinStream[bitnum++] = 77;
+                               BinStream[bitnum++] = 7;
                                errCnt++;
                        }               
                        lastBit += *clk;//skip over error
@@ -244,6 +242,7 @@ int manrawdecode(uint8_t * BitStream, size_t *size)
        size_t i, ii;
        uint16_t bestErr = 1000, bestRun = 0;
        if (size == 0) return -1;
+       //find correct start position [alignment]
        for (ii=0;ii<2;++ii){
                for (i=ii; i<*size-2; i+=2)
                        if (BitStream[i]==BitStream[i+1])
@@ -255,13 +254,14 @@ int manrawdecode(uint8_t * BitStream, size_t *size)
                }
                errCnt=0;
        }
+       //decode
        for (i=bestRun; i < *size-2; i+=2){
                if(BitStream[i] == 1 && (BitStream[i+1] == 0)){
                        BitStream[bitnum++]=0;
                } else if((BitStream[i] == 0) && BitStream[i+1] == 1){
                        BitStream[bitnum++]=1;
                } else {
-                       BitStream[bitnum++]=77;
+                       BitStream[bitnum++]=7;
                }
                if(bitnum>MaxBits) break;
        }
@@ -291,7 +291,7 @@ int BiphaseRawDecode(uint8_t *BitStream, size_t *size, int offset, int invert)
        for (i=offset; i<*size-3; i+=2){
                //check for phase error
                if (BitStream[i+1]==BitStream[i+2]) {
-                       BitStream[bitnum++]=77;
+                       BitStream[bitnum++]=7;
                        errCnt++;
                }
                if((BitStream[i]==1 && BitStream[i+1]==0) || (BitStream[i]==0 && BitStream[i+1]==1)){
@@ -299,7 +299,7 @@ int BiphaseRawDecode(uint8_t *BitStream, size_t *size, int offset, int invert)
                } else if((BitStream[i]==0 && BitStream[i+1]==0) || (BitStream[i]==1 && BitStream[i+1]==1)){
                        BitStream[bitnum++]=invert;
                } else {
-                       BitStream[bitnum++]=77;
+                       BitStream[bitnum++]=7;
                        errCnt++;
                }
                if(bitnum>MaxBits) break;
@@ -367,7 +367,7 @@ int askrawdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int max
                                BinStream[bitnum++] = *invert ^ 1;
                        } else {
                                if (bitnum > 0) {
-                                       BinStream[bitnum++]=77;
+                                       BinStream[bitnum++]=7;
                                        errCnt++;                                               
                                } 
                        }
@@ -784,8 +784,9 @@ int DetectASKClock(uint8_t dest[], size_t size, int *clock, int maxErr)
                for (i=8; i>1; i--){
                        if (clk[i] == ans) {
                                *clock = ans;
-                               clockFnd = i;
-                               break; //clock found but continue to find best startpos
+                               //clockFnd = i;
+                               return 0;  // for strong waves i don't use the 'best start position' yet...
+                               //break; //clock found but continue to find best startpos [not yet]
                        }
                }
        }
@@ -806,10 +807,11 @@ int DetectASKClock(uint8_t dest[], size_t size, int *clock, int maxErr)
                }else{
                        tol=0;
                }
-               if (!maxErr && loopCnt>clk[clkCnt]*3) loopCnt=clk[clkCnt]*3;
+               //if no errors allowed - keep start within the first clock
+               if (!maxErr && size > clk[clkCnt]*3 + tol) loopCnt=clk[clkCnt]*2;
                bestErr[clkCnt]=1000;
                //try lining up the peaks by moving starting point (try first few clocks)
-               for (ii=0; ii < loopCnt-tol-clk[clkCnt]; ii++){
+               for (ii=0; ii < loopCnt-clk[clkCnt]; ii++){
                        if (dest[ii] < peak && dest[ii] > low) continue;
 
                        errCnt=0;
@@ -849,7 +851,7 @@ int DetectASKClock(uint8_t dest[], size_t size, int *clock, int maxErr)
                        }
                }
        }
-       if (bestErr[best] > maxErr) return -1;
+       //if (bestErr[best] > maxErr) return -1;
        *clock = clk[best];
        return bestStart[best];
 }
@@ -1029,7 +1031,7 @@ 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){
+               if (BitStream[i]==7){
                        //ignore errors
                } else if (lastBit!=BitStream[i]){
                        lastBit=BitStream[i];
@@ -1222,7 +1224,7 @@ int nrzRawDemod(uint8_t *dest, size_t *size, int *clk, int *invert, int maxErr)
                        if (ignoreCnt == 0){
                                bitHigh = 0;
                                if (errBitHigh == 1){
-                                       dest[bitnum++] = 77;
+                                       dest[bitnum++] = 7;
                                        errCnt++;
                                }
                                errBitHigh=0;
@@ -1497,7 +1499,7 @@ int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert)
                                                //noise after a phase shift - ignore
                                        } else { //phase shift before supposed to based on clock
                                                errCnt++;
-                                               dest[numBits++] = 77;
+                                               dest[numBits++] = 7;
                                        }
                                } else if (i+1 > lastClkBit + *clock + tol + fc){
                                        lastClkBit += *clock; //no phase shift but clock bit