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iso15 sniff: add support for slow answers with single subcarrier

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Before this commit, slow answers was only supported for dual
subcarriers answers.
This commit is contained in:
Yann GASCUEL 2022-03-16 15:21:28 +01:00
commit 3880ef8da3
1 changed files with 12 additions and 13 deletions
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25
armsrc/iso15693.c
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@ -410,7 +410,7 @@ typedef struct {
//----------------------------------------------------------------------------- //-----------------------------------------------------------------------------
// DEMODULATE tag answer // DEMODULATE tag answer
//----------------------------------------------------------------------------- //-----------------------------------------------------------------------------
static RAMFUNC int Handle15693SamplesFromTag(uint16_t amplitude, DecodeTag_t *tag) { static RAMFUNC int Handle15693SamplesFromTag(uint16_t amplitude, DecodeTag_t *tag, bool recv_speed) {
switch (tag->state) { switch (tag->state) {
@ -454,7 +454,7 @@ static RAMFUNC int Handle15693SamplesFromTag(uint16_t amplitude, DecodeTag_t *ta
if (tag->posCount > 2) { if (tag->posCount > 2) {
tag->threshold_half += amplitude; // keep track of average high value tag->threshold_half += amplitude; // keep track of average high value
} }
if (tag->posCount == 10) { if (tag->posCount == (recv_speed?10:40)) {
tag->threshold_half >>= 2; // (4 times 1/2 average) tag->threshold_half >>= 2; // (4 times 1/2 average)
tag->state = STATE_TAG_SOF_HIGH_END; tag->state = STATE_TAG_SOF_HIGH_END;
} }
@ -468,7 +468,7 @@ static RAMFUNC int Handle15693SamplesFromTag(uint16_t amplitude, DecodeTag_t *ta
case STATE_TAG_SOF_HIGH_END: { case STATE_TAG_SOF_HIGH_END: {
// check for falling edge // check for falling edge
if (tag->posCount == 13 && amplitude < tag->threshold_sof) { if (tag->posCount == (recv_speed?13:52) && amplitude < tag->threshold_sof) {
tag->lastBit = SOF_PART1; // detected 1st part of SOF (12 samples low and 12 samples high) tag->lastBit = SOF_PART1; // detected 1st part of SOF (12 samples low and 12 samples high)
tag->shiftReg = 0; tag->shiftReg = 0;
tag->bitCount = 0; tag->bitCount = 0;
@ -480,7 +480,7 @@ static RAMFUNC int Handle15693SamplesFromTag(uint16_t amplitude, DecodeTag_t *ta
LED_C_ON(); LED_C_ON();
} else { } else {
tag->posCount++; tag->posCount++;
if (tag->posCount > 13) { // high phase too long if (tag->posCount > (recv_speed?13:52)) { // high phase too long
tag->posCount = 0; tag->posCount = 0;
tag->previous_amplitude = amplitude; tag->previous_amplitude = amplitude;
tag->state = STATE_TAG_SOF_LOW; tag->state = STATE_TAG_SOF_LOW;
@ -496,13 +496,13 @@ static RAMFUNC int Handle15693SamplesFromTag(uint16_t amplitude, DecodeTag_t *ta
tag->sum2 = 0; tag->sum2 = 0;
} }
if (tag->posCount <= 4) { if (tag->posCount <= (recv_speed?4:16)) {
tag->sum1 += amplitude; tag->sum1 += amplitude;
} else { } else {
tag->sum2 += amplitude; tag->sum2 += amplitude;
} }
if (tag->posCount == 8) { if (tag->posCount == (recv_speed?8:32)) {
if (tag->sum1 > tag->threshold_half && tag->sum2 > tag->threshold_half) { // modulation in both halves if (tag->sum1 > tag->threshold_half && tag->sum2 > tag->threshold_half) { // modulation in both halves
if (tag->lastBit == LOGIC0) { // this was already part of EOF if (tag->lastBit == LOGIC0) { // this was already part of EOF
tag->state = STATE_TAG_EOF; tag->state = STATE_TAG_EOF;
@ -583,13 +583,13 @@ static RAMFUNC int Handle15693SamplesFromTag(uint16_t amplitude, DecodeTag_t *ta
tag->sum2 = 0; tag->sum2 = 0;
} }
if (tag->posCount <= 4) { if (tag->posCount <= (recv_speed?4:16)) {
tag->sum1 += amplitude; tag->sum1 += amplitude;
} else { } else {
tag->sum2 += amplitude; tag->sum2 += amplitude;
} }
if (tag->posCount == 8) { if (tag->posCount == (recv_speed?8:32)) {
if (tag->sum1 > tag->threshold_half && tag->sum2 < tag->threshold_half) { // modulation in first half if (tag->sum1 > tag->threshold_half && tag->sum2 < tag->threshold_half) { // modulation in first half
tag->posCount = 0; tag->posCount = 0;
tag->state = STATE_TAG_EOF_TAIL; tag->state = STATE_TAG_EOF_TAIL;
@ -610,13 +610,13 @@ static RAMFUNC int Handle15693SamplesFromTag(uint16_t amplitude, DecodeTag_t *ta
tag->sum2 = 0; tag->sum2 = 0;
} }
if (tag->posCount <= 4) { if (tag->posCount <= (recv_speed?4:16)) {
tag->sum1 += amplitude; tag->sum1 += amplitude;
} else { } else {
tag->sum2 += amplitude; tag->sum2 += amplitude;
} }
if (tag->posCount == 8) { if (tag->posCount == (recv_speed?8:32)) {
if (tag->sum1 < tag->threshold_half && tag->sum2 < tag->threshold_half) { // no modulation in both halves if (tag->sum1 < tag->threshold_half && tag->sum2 < tag->threshold_half) { // no modulation in both halves
LED_C_OFF(); LED_C_OFF();
return true; return true;
@ -719,7 +719,7 @@ int GetIso15693AnswerFromTag(uint8_t *response, uint16_t max_len, uint16_t timeo
} }
} }
if (Handle15693SamplesFromTag(tagdata, dt)) { if (Handle15693SamplesFromTag(tagdata, dt, true)) {
*eof_time = dma_start_time + (samples * 16) - DELAY_TAG_TO_ARM; // end of EOF *eof_time = dma_start_time + (samples * 16) - DELAY_TAG_TO_ARM; // end of EOF
@ -1730,7 +1730,7 @@ void SniffIso15693(uint8_t jam_search_len, uint8_t *jam_search_string, bool icla
if (!expect_fsk_answer) if (!expect_fsk_answer)
{ {
if (Handle15693SamplesFromTag((sniffdata >> 4) << 2, &dtag)) { if (Handle15693SamplesFromTag((sniffdata >> 4) << 2, &dtag, expect_fast_answer)) {
uint32_t eof_time = dma_start_time + (samples * 16) - DELAY_TAG_TO_ARM_SNIFF; // end of EOF uint32_t eof_time = dma_start_time + (samples * 16) - DELAY_TAG_TO_ARM_SNIFF; // end of EOF
if (dtag.lastBit == SOF_PART2) { if (dtag.lastBit == SOF_PART2) {
@ -1786,7 +1786,6 @@ void SniffIso15693(uint8_t jam_search_len, uint8_t *jam_search_string, bool icla
} }
} }
} }
} }
FpgaDisableTracing(); FpgaDisableTracing();