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Merge branch 'master' of https://github.com/jgromes/RadioLib

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This commit is contained in:
jgromes 2022-07-03 11:06:46 +02:00
commit 756125cd8b
2 changed files with 60 additions and 14 deletions
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65
src/modules/SX127x/SX127x.cpp
View file

@ -147,17 +147,8 @@ int16_t SX127x::transmit(uint8_t* data, size_t len, uint8_t addr) {
int16_t modem = getActiveModem();
uint32_t start = 0;
if(modem == RADIOLIB_SX127X_LORA) {
// calculate timeout (150 % of expected time-one-air)
float symbolLength = (float)(uint32_t(1) <<_sf) / (float)_bw;
float de = 0;
if(symbolLength >= 16.0) {
de = 1;
}
float ih = (float)_mod->SPIgetRegValue(RADIOLIB_SX127X_REG_MODEM_CONFIG_1, 0, 0);
float crc = (float)(_mod->SPIgetRegValue(RADIOLIB_SX127X_REG_MODEM_CONFIG_2, 2, 2) >> 2);
float n_pre = (float)((_mod->SPIgetRegValue(RADIOLIB_SX127X_REG_PREAMBLE_MSB) << 8) | _mod->SPIgetRegValue(RADIOLIB_SX127X_REG_PREAMBLE_LSB));
float n_pay = 8.0 + max(ceil((8.0 * (float)len - 4.0 * (float)_sf + 28.0 + 16.0 * crc - 20.0 * ih)/(4.0 * (float)_sf - 8.0 * de)) * (float)_cr, 0.0);
uint32_t timeout = ceil(symbolLength * (n_pre + n_pay + 4.25) * 1500.0);
// calculate timeout (150 % of expected time-on-air)
uint32_t timeout = getTimeOnAir(len) * 1.5;
// start transmission
state = startTransmit(data, len, addr);
@ -175,7 +166,7 @@ int16_t SX127x::transmit(uint8_t* data, size_t len, uint8_t addr) {
} else if(modem == RADIOLIB_SX127X_FSK_OOK) {
// calculate timeout (5ms + 500 % of expected time-on-air)
uint32_t timeout = 5000000 + (uint32_t)((((float)(len * 8)) / (_br * 1000.0)) * 5000000.0);
uint32_t timeout = 5000 + getTimeOnAir(len) * 5;
// start transmission
state = startTransmit(data, len, addr);
@ -227,8 +218,8 @@ int16_t SX127x::receive(uint8_t* data, size_t len) {
}
} else if(modem == RADIOLIB_SX127X_FSK_OOK) {
// calculate timeout (500 % of expected time-one-air)
uint32_t timeout = (uint32_t)((((float)(len * 8)) / (_br * 1000.0)) * 5000000.0);
// calculate timeout (500 % of expected time-on-air)
uint32_t timeout = getTimeOnAir(len) * 5;
// set mode to receive
state = startReceive(len, RADIOLIB_SX127X_RX);
@ -1047,6 +1038,52 @@ int16_t SX127x::variablePacketLengthMode(uint8_t maxLen) {
return(SX127x::setPacketMode(RADIOLIB_SX127X_PACKET_VARIABLE, maxLen));
}
uint32_t SX127x::getTimeOnAir(size_t len) {
// check active modem
uint8_t modem = getActiveModem();
if (modem == RADIOLIB_SX127X_LORA) {
// Get symbol length in us
float symbolLength = (float) (uint32_t(1) << _sf) / (float) _bw;
// Get Low Data Rate optimization flag
float de = 0;
if (symbolLength >= 16.0) {
de = 1;
}
// Get explicit/implicit header enabled flag
float ih = (float) _mod->SPIgetRegValue(RADIOLIB_SX127X_REG_MODEM_CONFIG_1, 0, 0);
// Get CRC enabled flag
float crc = (float) (_mod->SPIgetRegValue(RADIOLIB_SX127X_REG_MODEM_CONFIG_2, 2, 2) >> 2);
// Get number of bits preamble
float n_pre = (float) ((_mod->SPIgetRegValue(RADIOLIB_SX127X_REG_PREAMBLE_MSB) << 8) | _mod->SPIgetRegValue(RADIOLIB_SX127X_REG_PREAMBLE_LSB));
// Get number of bits payload
float n_pay = 8.0 + max(ceil((8.0 * (float) len - 4.0 * (float) _sf + 28.0 + 16.0 * crc - 20.0 * ih) / (4.0 * (float) _sf - 8.0 * de)) * (float) _cr, 0.0);
// Get time-on-air in us
return ceil(symbolLength * (n_pre + n_pay + 4.25)) * 1000;
} else if(modem == RADIOLIB_SX127X_FSK_OOK) {
// Get number of bits preamble
float n_pre = (float) ((_mod->SPIgetRegValue(RADIOLIB_SX127X_REG_PREAMBLE_MSB_FSK) << 8) | _mod->SPIgetRegValue(RADIOLIB_SX127X_REG_PREAMBLE_LSB_FSK)) * 8;
//Get the number of bits of the sync word
float n_syncWord = (float) (_mod->SPIgetRegValue(RADIOLIB_SX127X_REG_SYNC_CONFIG, 2, 0) + 1) * 8;
//Get CRC bits
float crc = (_mod->SPIgetRegValue(RADIOLIB_SX127X_REG_PACKET_CONFIG_1, 4, 4) == RADIOLIB_SX127X_CRC_ON) * 16;
if (_packetLengthConfig == RADIOLIB_SX127X_PACKET_FIXED) {
//If Packet size fixed -> len = fixed packet length
len = _mod->SPIgetRegValue(RADIOLIB_SX127X_REG_PAYLOAD_LENGTH_FSK);
} else {
//if packet variable -> Add 1 extra byte for payload length
len += 1;
}
// Calculate time-on-air in us {[(length in bytes) * (8 bits / 1 byte)] / [(Bit Rate in kbps) * (1000 bps / 1 kbps)]} * (1000000 us in 1 sec)
return (uint32_t) (((crc + n_syncWord + n_pre + (float) (len * 8)) / (_br * 1000.0)) * 1000000.0);
} else {
return(RADIOLIB_ERR_UNKNOWN);
}
}
int16_t SX127x::setCrcFiltering(bool crcOn) {
_crcOn = crcOn;

9
src/modules/SX127x/SX127x.h
View file

@ -980,6 +980,15 @@ class SX127x: public PhysicalLayer {
*/
int16_t variablePacketLengthMode(uint8_t maxLen = RADIOLIB_SX127X_MAX_PACKET_LENGTH_FSK);
/*!
\brief Get expected time-on-air for a given size of payload
\param len Payload length in bytes.
\returns Expected time-on-air in microseconds.
*/
uint32_t getTimeOnAir(size_t len);
/*!
\brief Enable CRC filtering and generation.