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Created new detectclock function + EM decode addons

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new detectclock is somewhat more reliable for ASK modulated tags.  added
this detect to askrawdemod if no clock in passed as an argument.  also
added more EM ID formats to output
This commit is contained in:
marshmellow42 2014-12-24 11:48:41 -05:00
commit 0e74c023bd
2 changed files with 113 additions and 31 deletions
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92
client/graph.c
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@ -46,24 +46,27 @@ int ClearGraph(int redraw)
/*
* Detect clock rate
*/
int DetectClock(int peak)
//decommissioned - has difficulty detecting rf/32 and only works if data is manchester encoded
/*
int DetectClock2(int peak)
{
int i;
int clock = 0xFFFF;
int lastpeak = 0;
/* Detect peak if we don't have one */
// Detect peak if we don't have one
if (!peak)
for (i = 0; i < GraphTraceLen; ++i)
if (GraphBuffer[i] > peak)
peak = GraphBuffer[i];
// peak=(int)(peak*.75);
for (i = 1; i < GraphTraceLen; ++i)
{
/* If this is the beginning of a peak */
if (GraphBuffer[i - 1] != GraphBuffer[i] && GraphBuffer[i] == peak)
// If this is the beginning of a peak
if (GraphBuffer[i - 1] != GraphBuffer[i] && GraphBuffer[i] >= peak)
{
/* Find lowest difference between peaks */
// Find lowest difference between peaks
if (lastpeak && i - lastpeak < clock)
clock = i - lastpeak;
lastpeak = i;
@ -72,12 +75,84 @@ int DetectClock(int peak)
return clock;
}
*/
// 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 DetectClock(int peak)
{
int i=0;
int low=0;
int clk[]={16,32,40,50,64,100,128,256};
if (!peak){
for (i=0;i<GraphTraceLen;++i){
if(GraphBuffer[i]>peak){
peak = GraphBuffer[i];
}
if(GraphBuffer[i]<low){
low = GraphBuffer[i];
}
}
peak=(int)(peak*.75);
low= (int)(low*.75);
}
//int numbits;
int ii;
int loopCnt = 256;
if (GraphTraceLen<loopCnt) loopCnt = GraphTraceLen;
int clkCnt;
int tol = 0;
int bestErr=1000;
int errCnt[]={0,0,0,0,0,0,0,0};
// int good;
for(clkCnt=0; clkCnt<6;++clkCnt){
if (clk[clkCnt]==32){
tol=1;
}else{
tol=0;
}
bestErr=1000;
for (ii=0; ii<loopCnt; ++ii){
if ((GraphBuffer[ii]>=peak) || (GraphBuffer[ii]<=low)){
//numbits=0;
//good=1;
errCnt[clkCnt]=0;
for (i=0; i<((int)(GraphTraceLen/clk[clkCnt])-1); ++i){
if (GraphBuffer[ii+(i*clk[clkCnt])]>=peak || GraphBuffer[ii+(i*clk[clkCnt])]<=low){
//numbits++;
}else if(GraphBuffer[ii+(i*clk[clkCnt])-tol]>=peak || GraphBuffer[ii+(i*clk[clkCnt])-tol]<=low){
}else if(GraphBuffer[ii+(i*clk[clkCnt])+tol]>=peak || GraphBuffer[ii+(i*clk[clkCnt])+tol]<=low){
}else{ //error no peak detected
//numbits=0;
//good=0;
errCnt[clkCnt]++;
//break;
}
}
if(errCnt[clkCnt]==0) return clk[clkCnt];
if(errCnt[clkCnt]<bestErr) bestErr=errCnt[clkCnt];
}
}
errCnt[clkCnt]=bestErr;
}
int iii=0;
int best=0;
for (iii=0; iii<6;++iii){
if (errCnt[iii]<errCnt[best]){
best = iii;
}
}
PrintAndLog("clkCnt: %d, ii: %d, i: %d peak: %d, low: %d, errcnt: %d, errCnt64: %d",clkCnt,ii,i,peak,low,errCnt[best],errCnt[4]);
return clk[best];
}
/* Get or auto-detect clock rate */
int GetClock(const char *str, int peak, int verbose)
{
int clock;
// int clock2;
sscanf(str, "%i", &clock);
if (!strcmp(str, ""))
clock = 0;
@ -86,9 +161,12 @@ int GetClock(const char *str, int peak, int verbose)
if (!clock)
{
clock = DetectClock(peak);
//clock2 = DetectClock2(peak);
/* Only print this message if we're not looping something */
if (!verbose)
if (!verbose){
PrintAndLog("Auto-detected clock rate: %d", clock);
//PrintAndLog("clock2: %d",clock2);
}
}
return clock;