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Improve the synchronisation.

This commit is contained in:
Jonathan Naylor 2016-07-11 20:33:16 +01:00
parent 2f648b3f79
commit 8278415572
1 changed files with 30 additions and 47 deletions
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77
DStarRX.cpp
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@ -31,6 +31,10 @@ const uint32_t INC = PLLINC / 32U;
const unsigned int MAX_SYNC_BITS = 50U * DSTAR_DATA_LENGTH_BITS;
const unsigned int SYNC_POS = 21U * DSTAR_DATA_LENGTH_BITS;
const unsigned int SYNC_SCAN_START = SYNC_POS - 3U;
const unsigned int SYNC_SCAN_END = SYNC_POS + 3U;
const q15_t THRESHOLD = 0;
// D-Star bit order version of 0x55 0x55 0x6E 0x0A
@ -337,25 +341,13 @@ void CDStarRX::processNone(bool bit)
io.setDecode(true);
io.setADCDetection(true);
#if defined(WANT_DEBUG)
q15_t min = 16000;
q15_t max = -16000;
for (uint8_t i = 0U; i < DSTAR_DATA_SYNC_LENGTH_BITS; i++) {
if (m_samples[i] > max)
max = m_samples[i];
if (m_samples[i] < min)
min = m_samples[i];
}
DEBUG3("DStarRX: data sync found min/max", min, max);
#endif
serial.writeDStarData(DSTAR_DATA_SYNC_BYTES, DSTAR_DATA_LENGTH_BYTES);
::memset(m_rxBuffer, 0x00U, DSTAR_DATA_LENGTH_BYTES);
m_rxBufferBits = 0U;
m_dataBits = MAX_SYNC_BITS;
m_rxState = DSRXS_DATA;
m_dataBits = 0U;
m_rxState = DSRXS_DATA;
return;
}
}
@ -383,8 +375,8 @@ void CDStarRX::processHeader(bool bit)
::memset(m_rxBuffer, 0x00U, DSTAR_DATA_LENGTH_BYTES);
m_rxBufferBits = 0U;
m_rxState = DSRXS_DATA;
m_dataBits = MAX_SYNC_BITS;
m_rxState = DSRXS_DATA;
m_dataBits = SYNC_POS - DSTAR_DATA_LENGTH_BITS + 1U;
} else {
// The checksum failed, return to looking for syncs
m_rxState = DSRXS_NONE;
@ -416,34 +408,38 @@ void CDStarRX::processData(bool bit)
// Fuzzy matching of the data sync bit sequence
bool syncSeen = false;
if (m_rxBufferBits >= (DSTAR_DATA_LENGTH_BITS - 3U)) {
if (m_dataBits >= SYNC_SCAN_START && m_dataBits <= (SYNC_POS + 1U)) {
if (countBits32((m_patternBuffer & DATA_SYNC_MASK) ^ DATA_SYNC_DATA) <= DATA_SYNC_ERRS) {
#if defined(WANT_DEBUG)
if (m_rxBufferBits < DSTAR_DATA_LENGTH_BITS)
DEBUG2("DStarRX: found data sync in Data, early", DSTAR_DATA_LENGTH_BITS - m_rxBufferBits);
if (m_dataBits < SYNC_POS)
DEBUG2("DStarRX: found data sync in Data, early", SYNC_POS - m_dataBits);
else
DEBUG1("DStarRX: found data sync in Data");
q15_t min = 16000;
q15_t max = -16000;
for (uint8_t i = 0U; i < DSTAR_DATA_SYNC_LENGTH_BITS; i++) {
if (m_samples[i] > max)
max = m_samples[i];
if (m_samples[i] < min)
min = m_samples[i];
}
DEBUG3("DStarRX: data sync found min/max", min, max);
#endif
m_rxBufferBits = DSTAR_DATA_LENGTH_BITS;
m_dataBits = MAX_SYNC_BITS;
syncSeen = true;
m_dataBits = 0U;
syncSeen = true;
}
}
// Check to see if the sync is arriving late
if (m_dataBits == SYNC_POS) {
for (uint8_t i = 1U; i <= 3U; i++) {
uint32_t syncMask = DATA_SYNC_MASK >> i;
uint32_t syncData = DATA_SYNC_DATA >> i;
if (countBits32((m_patternBuffer & syncMask) ^ syncData) <= DATA_SYNC_ERRS) {
DEBUG2("DStarRX: found data sync in Data, late", i);
m_rxBufferBits -= i;
m_dataBits -= i;
break;
}
}
}
m_dataBits++;
// We've not seen a data sync for too long, signal RXLOST and change to RX_NONE
m_dataBits--;
if (m_dataBits == 0U) {
if (m_dataBits >= MAX_SYNC_BITS) {
DEBUG1("DStarRX: data sync timed out, lost lock");
io.setDecode(false);
@ -455,19 +451,6 @@ void CDStarRX::processData(bool bit)
return;
}
// Check to see if the sync is arriving late
if (m_rxBufferBits == DSTAR_DATA_LENGTH_BITS && !syncSeen) {
for (uint8_t i = 1U; i <= 3U; i++) {
uint32_t syncMask = DATA_SYNC_MASK >> i;
uint32_t syncData = DATA_SYNC_DATA >> i;
if (countBits32((m_patternBuffer & syncMask) ^ syncData) <= DATA_SYNC_ERRS) {
DEBUG2("DStarRX: found data sync in Data, late", i);
m_rxBufferBits -= i;
break;
}
}
}
// Send a data frame to the host if the required number of bits have been received, or if a data sync has been seen
if (m_rxBufferBits == DSTAR_DATA_LENGTH_BITS) {
if (syncSeen) {