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CHG: @Marshmellow42 's fixes. ref: e88096ba25

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This commit is contained in:
iceman1001 2017-02-24 01:14:47 +01:00
commit 5215a87442
6 changed files with 208 additions and 42 deletions
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42
common/lfdemod.c
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@ -74,7 +74,7 @@ size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t p
parityWd = (parityWd << 1) | BitStream[startIdx+word+bit];
BitStream[j++] = (BitStream[startIdx+word+bit]);
}
if (word+pLen >= bLen) break;
if (word+pLen > bLen) break;
j--; // overwrite parity with next data
// if parity fails then return 0
@ -158,7 +158,7 @@ bool preambleSearchEx(uint8_t *BitStream, uint8_t *preamble, size_t pLen, size_t
uint8_t foundCnt = 0;
for (int idx = 0; idx < *size - pLen; idx++){
if (memcmp(BitStream+idx, preamble, pLen) == 0){
if (g_debugMode) prnt("DEBUG: preamble found at %u", idx);
if (g_debugMode) prnt("DEBUG: preamble found at %i", idx);
//first index found
foundCnt++;
if (foundCnt == 1){
@ -205,12 +205,10 @@ size_t findModStart(uint8_t dest[], size_t size, uint8_t threshold_value, uint8_
// 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)
{
//allow only 1s and 0s
// only checking first bitvalue?!
// sanity check
if (BitStream[1] > 1) return 0;
uint32_t i = 0, idx = 0, parityBits = 0;
uint8_t fmtlen = 0;
uint8_t fmtlen;
*startIdx = 0;
// preamble 0111111111
@ -220,23 +218,27 @@ uint8_t Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx, uint32_
return 0;
if (*size < 64) return 0;
fmtlen = (*size > 64) ? 22 : 10;
fmtlen = (*size == 110) ? 22 : 10;
idx = *startIdx + sizeof(preamble);
//skip last 4bit parity row for simplicity
*size = removeParity(BitStream, *startIdx + sizeof(preamble), 5, 0, fmtlen * 5);
switch (*size) {
case 40: {
// std em410x format
*hi = 0;
*lo = ((uint64_t)(bytebits_to_byte(BitStream, 8)) << 32) | (bytebits_to_byte(BitStream + 8, 32));
break;
}
case 88: {
// long em format
*hi = (bytebits_to_byte(BitStream, 24));
*lo = ((uint64_t)(bytebits_to_byte(BitStream + 24, 32)) << 32) | (bytebits_to_byte(BitStream + 24 + 32, 32));
break;
}
default: return 0;
//loop through 10 or 22 sets of 5 bits (50-10p = 40 bits or 88 bits)
for (i=0; i < fmtlen; i++){
parityBits = bytebits_to_byte(BitStream + (i*5) + idx, 5);
//check even parity
if (parityTest(parityBits, 5, 0) == 0) return 0;
//set uint64 with ID from BitStream
for (uint8_t j = 0; j < 4; j++){
*hi = (*hi << 1) | (*lo >> 63);
*lo = (*lo << 1) | (BitStream[(i*5) + j + idx]);
}
}
//skip last 5 bit parity test for simplicity.
// *size = 64 | 128;
return 1;
}