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New version of mandemod 64 by Samy: now does not need 'askdemod' anymore, and support for more EM-like tag types.

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edouard@lafargue.name 2009-06-30 05:58:53 +00:00
parent 16e590fd2b
commit c9f99c010e
1 changed files with 89 additions and 8 deletions
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97
winsrc/command.cpp
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@ -1622,15 +1622,24 @@ static void Cmdaskdemod(char *str) {
* Typical values can be 64, 32, 128...
*/
static void Cmdmanchesterdemod(char *str) {
int i;
int i, j;
int bit;
int clock;
int lastval;
int low = 0;
int high = 0;
int hithigh, hitlow, first;
int lc = 0;
int bitidx = 0;
int bit2idx = 0;
int warnings = 0;
sscanf(str, "%i", &clock);
if (!clock)
{
PrintToScrollback("You must provide a clock rate.");
return;
}
int tolerance = clock/4;
/* Holds the decoded bitstream: each clock period contains 2 bits */
@ -1642,21 +1651,77 @@ static void Cmdmanchesterdemod(char *str) {
/* large array */
int BitStream[MAX_GRAPH_TRACE_LEN];
/* Detect high and lows */
for (i = 0; i < GraphTraceLen; i++)
{
if (GraphBuffer[i] > high)
high = GraphBuffer[i];
else if (GraphBuffer[i] < low)
low = GraphBuffer[i];
}
/* Detect first transition */
/* Lo-Hi (arbitrary) */
for(i=1;i<GraphTraceLen;i++) {
if (GraphBuffer[i-1]<GraphBuffer[i]) {
for (i = 0; i < GraphTraceLen; i++)
{
if (GraphBuffer[i] == low)
{
// BitStream[0]=0; // Previous state = 0;
lastval = i;
BitStream[0]=0; // Previous state = 0;
break;
}
}
//PrintToScrollback("cool %d %d %d %d", low, high, lastval, GraphBuffer[i]);
/* If we're not working with 1/0s, demod based off clock */
if (high != 1)
{
bit = 0;
for (i = 0; i < (GraphTraceLen / clock); i++)
{
hithigh = 0;
hitlow = 0;
first = 1;
/* Find out if we hit both high and low peaks */
for (j = 0; j < clock; j++)
{
if (GraphBuffer[(i * clock) + j] == high)
hithigh = 1;
else if (GraphBuffer[(i * clock) + j] == low)
hitlow = 1;
/* it doesn't count if it's the first part of our read
because it's really just trailing from the last sequence */
if (first && (hithigh || hitlow))
hithigh = hitlow = 0;
else
first = 0;
if (hithigh && hitlow)
break;
}
/* If we didn't hit both high and low peaks, we had a bit transition */
if (!hithigh || !hitlow)
bit ^= 1;
BitStream[bit2idx++] = bit;
}
}
/* standard 1/0 bitstream */
else
{
/* Then detect duration between 2 successive transitions */
for(bitidx = 1 ;i<GraphTraceLen;i++) {
if (GraphBuffer[i-1] != GraphBuffer[i]) {
for (bitidx = 1; i < GraphTraceLen; i++)
{
if (GraphBuffer[i-1] != GraphBuffer[i])
{
lc = i-lastval;
lastval = i;
// Error check: if bitidx becomes too large, we do not
// have a Manchester encoded bitstream or the clock is really
// wrong!
@ -1675,8 +1740,15 @@ static void Cmdmanchesterdemod(char *str) {
BitStream[bitidx++]=GraphBuffer[i-1];
} else {
// Error
warnings++;
PrintToScrollback("Warning: Manchester decode error for pulse width detection.");
PrintToScrollback("(too many of those messages mean either the stream is not Manchester encoded, or clock is wrong)");
if (warnings > 100)
{
PrintToScrollback("Error: too many detection errors, aborting.");
return;
}
}
}
}
@ -1693,11 +1765,20 @@ static void Cmdmanchesterdemod(char *str) {
// We cannot end up in this state, this means we are unsynchronized,
// move up 1 bit:
i++;
warnings++;
PrintToScrollback("Unsynchronized, resync...");
PrintToScrollback("(too many of those messages mean the stream is not Manchester encoded)");
if (warnings > 100)
{
PrintToScrollback("Error: too many decode errors, aborting.");
return;
}
}
}
PrintToScrollback("Manchester decoded bitstream \n---------");
}
PrintToScrollback("Manchester decoded bitstream");
// Now output the bitstream to the scrollback by line of 16 bits
for (i = 0; i < (bit2idx-16); i+=16) {
PrintToScrollback("%i %i %i %i %i %i %i %i %i %i %i %i %i %i %i %i",