//by marshmellow
//takes 1s and 0s and searches for EM410x format - output EM ID
// actually, no arguments needed - built this way in case we want this to be a direct call from "data " cmds in the future
-uint8_t Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx, uint32_t *hi, uint64_t *lo)
+int Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx, uint32_t *hi, uint64_t *lo)
{
// sanity check
- if (BitStream[1] > 1) return 0;
+ if (BitStream[1] > 1) return -1;
uint8_t fmtlen;
*startIdx = 0;
// include 0 in front to help get start pos
uint8_t preamble[] = {0,1,1,1,1,1,1,1,1,1};
if (!preambleSearch(BitStream, preamble, sizeof(preamble), size, startIdx))
- return 0;
- if (*size < 64) return 0;
+ return -2;
+ if (*size < 64) return -3;
fmtlen = (*size == 110) ? 22 : 10;
*lo = ((uint64_t)(bytebits_to_byte(BitStream + 24, 32)) << 32) | (bytebits_to_byte(BitStream + 24 + 32, 32));
break;
}
- default: return 0;
-
+ default: return -4;
}
return 1;
}
//by marshmellow
//demodulates strong heavily clipped samples
+//RETURN: num of errors. if 0, is ok.
int cleanAskRawDemod(uint8_t *BinStream, size_t *size, int clk, int invert, int high, int low)
{
size_t bitCnt=0, smplCnt=0, errCnt=0;
//by marshmellow
//take 10 and 01 and manchester decode
//run through 2 times and take least errCnt
-int manrawdecode(uint8_t * BitStream, size_t *size, uint8_t invert){
+int manrawdecode(uint8_t *BitStream, size_t *size, uint8_t invert){
+
+ // sanity check
+ if (*size < 16) return -1;
+
int errCnt = 0, bestErr = 1000;
uint16_t bitnum = 0, MaxBits = 512, bestRun = 0;
size_t i, k;
- if (*size < 16) return -1;
+
//find correct start position [alignment]
- for (k=0; k < 2; ++k){
- for (i=k; i<*size-3; i += 2)
+ for (k = 0; k < 2; ++k){
+ for (i = k; i < *size-3; i += 2) {
if (BitStream[i] == BitStream[i+1])
errCnt++;
-
+ }
if (bestErr > errCnt){
bestErr = errCnt;
bestRun = k;
}
- errCnt=0;
+ errCnt = 0;
}
+
//decode
- for (i=bestRun; i < *size-3; i += 2){
+ for (i = bestRun; i < *size-3; i += 2){
if (BitStream[i] == 1 && (BitStream[i+1] == 0)){
BitStream[bitnum++] = invert;
} else if ((BitStream[i] == 0) && BitStream[i+1] == 1){
} else {
BitStream[bitnum++] = 7;
}
- if (bitnum>MaxBits) break;
+ if (bitnum > MaxBits) break;
}
- *size=bitnum;
+ *size = bitnum;
return bestErr;
}