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Merge pull request #484 from liquidraver/dev

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LR's (corrected) calculation instead of SX and minor changes
This commit is contained in:
ripplebiz
2025-07-05 20:38:42 +10:00
committed by GitHub
parent ff9699c071 fa481e832b
commit ae5e3588ba
2 changed files with 52 additions and 27 deletions
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76
src/helpers/CustomLR1110.h
View File

@@ -10,34 +10,58 @@ class CustomLR1110 : public LR1110 {
CustomLR1110(Module *mod) : LR1110(mod) { }
RadioLibTime_t getTimeOnAir(size_t len) override {
uint32_t symbolLength_us = ((uint32_t)(1000 * 10) << this->spreadingFactor) / (this->bandwidthKhz * 10) ;
uint8_t sfCoeff1_x4 = 17; // (4.25 * 4)
uint8_t sfCoeff2 = 8;
if(this->spreadingFactor == 5 || this->spreadingFactor == 6) {
sfCoeff1_x4 = 25; // 6.25 * 4
sfCoeff2 = 0;
}
uint8_t sfDivisor = 4*this->spreadingFactor;
if(symbolLength_us >= 16000) {
sfDivisor = 4*(this->spreadingFactor - 2);
}
const int8_t bitsPerCrc = 16;
const int8_t N_symbol_header = this->headerType == RADIOLIB_SX126X_LORA_HEADER_EXPLICIT ? 20 : 0;
// numerator of equation in section 6.1.4 of SX1268 datasheet v1.1 (might not actually be bitcount, but it has len * 8)
int16_t bitCount = (int16_t) 8 * len + this->crcTypeLoRa * bitsPerCrc - 4 * this->spreadingFactor + sfCoeff2 + N_symbol_header;
if(bitCount < 0) {
bitCount = 0;
}
// add (sfDivisor) - 1 to the numerator to give integer CEIL(...)
uint16_t nPreCodedSymbols = (bitCount + (sfDivisor - 1)) / (sfDivisor);
// preamble can be 65k, therefore nSymbol_x4 needs to be 32 bit
uint32_t nSymbol_x4 = (this->preambleLengthLoRa + 8) * 4 + sfCoeff1_x4 + nPreCodedSymbols * (this->codingRate + 4) * 4;
return((symbolLength_us * nSymbol_x4) / 4);
// calculate number of symbols
float N_symbol = 0;
if(this->codingRate <= RADIOLIB_LR11X0_LORA_CR_4_8_SHORT) {
// legacy coding rate - nice and simple
// get SF coefficients
float coeff1 = 0;
int16_t coeff2 = 0;
int16_t coeff3 = 0;
if(this->spreadingFactor < 7) {
// SF5, SF6
coeff1 = 6.25;
coeff2 = 4*this->spreadingFactor;
coeff3 = 4*this->spreadingFactor;
} else if(this->spreadingFactor < 11) {
// SF7. SF8, SF9, SF10
coeff1 = 4.25;
coeff2 = 4*this->spreadingFactor + 8;
coeff3 = 4*this->spreadingFactor;
} else {
// SF11, SF12
coeff1 = 4.25;
coeff2 = 4*this->spreadingFactor + 8;
coeff3 = 4*(this->spreadingFactor - 2);
}
// get CRC length
int16_t N_bitCRC = 16;
if(this->crcTypeLoRa == RADIOLIB_LR11X0_LORA_CRC_DISABLED) {
N_bitCRC = 0;
}
// get header length
int16_t N_symbolHeader = 20;
if(this->headerType == RADIOLIB_LR11X0_LORA_HEADER_IMPLICIT) {
N_symbolHeader = 0;
}
// calculate number of LoRa preamble symbols - NO! Lora preamble is already in symbols
// uint32_t N_symbolPreamble = (this->preambleLengthLoRa & 0x0F) * (uint32_t(1) << ((this->preambleLengthLoRa & 0xF0) >> 4));
// calculate the number of symbols - nope
// N_symbol = (float)N_symbolPreamble + coeff1 + 8.0f + ceilf((float)RADIOLIB_MAX((int16_t)(8 * len + N_bitCRC - coeff2 + N_symbolHeader), (int16_t)0) / (float)coeff3) * (float)(this->codingRate + 4);
// calculate the number of symbols - using only preamblelora because it's already in symbols
N_symbol = (float)preambleLengthLoRa + coeff1 + 8.0f + ceilf((float)RADIOLIB_MAX((int16_t)(8 * len + N_bitCRC - coeff2 + N_symbolHeader), (int16_t)0) / (float)coeff3) * (float)(this->codingRate + 4);
} else {
// long interleaving - not needed for this modem
}
// get time-on-air in us
return(((uint32_t(1) << this->spreadingFactor) / this->bandwidthKhz) * N_symbol * 1000.0f);
}
bool isReceiving() {
uint16_t irq = getIrqStatus();
bool detected = ((irq & LR1110_IRQ_HEADER_VALID) || (irq & LR1110_IRQ_HAS_PREAMBLE));

3
variants/t1000-e/target.cpp
View File

@@ -61,7 +61,8 @@ bool radio_init() {
return false; // fail
}
radio.setCRC(1);
radio.setCRC(2);
radio.explicitHeader();
#ifdef RF_SWITCH_TABLE
radio.setRfSwitchTable(rfswitch_dios, rfswitch_table);