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adjust lf t55xx read commands

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seems to make them a lot more accurate for me
This commit is contained in:
marshmellow42 2015-10-15 01:09:49 -04:00
commit f4eadf8a50
3 changed files with 92 additions and 30 deletions
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21
common/lfdemod.c
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@ -369,7 +369,9 @@ size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow
if (fclow==0) fclow=8;
//set the threshold close to 0 (graph) or 128 std to avoid static
uint8_t threshold_value = 123;
size_t preLastSample = 0;
size_t LastSample = 0;
size_t currSample = 0;
// sync to first lo-hi transition, and threshold
// Need to threshold first sample
@ -389,13 +391,22 @@ size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow
// Check for 0->1 transition
if (dest[idx-1] < dest[idx]) { // 0 -> 1 transition
if ((idx-last_transition)<(fclow-2)){ //0-5 = garbage noise
preLastSample = LastSample;
LastSample = currSample;
currSample = idx-last_transition;
if (currSample < (fclow-2)){ //0-5 = garbage noise
//do nothing with extra garbage
} else if ((idx-last_transition) < (fchigh-1)) { //6-8 = 8 waves
} else if (currSample < (fchigh-1)) { //6-8 = 8 sample waves
if (LastSample > (fchigh-2) && preLastSample < (fchigh-1)){
dest[numBits-1]=1; //correct last 9 wave surrounded by 8 waves
}
dest[numBits++]=1;
} else if ((idx-last_transition) > (fchigh+1) && !numBits) { //12 + and first bit = garbage
} else if (currSample > (fchigh+1) && !numBits) { //12 + and first bit = garbage
//do nothing with beginning garbage
} else { //9+ = 10 waves
} else if (currSample == (fclow+1) && LastSample == (fclow-1)) { // had a 7 then a 9 should be two 8's
dest[numBits++]=1;
} else { //9+ = 10 sample waves
dest[numBits++]=0;
}
last_transition = idx;