129 lines
2.9 KiB
C++
129 lines
2.9 KiB
C++
#include "FSK4.h"
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#include <math.h>
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#if !RADIOLIB_EXCLUDE_FSK4
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FSK4Client::FSK4Client(PhysicalLayer* phy) {
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phyLayer = phy;
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#if !RADIOLIB_EXCLUDE_AFSK
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audioClient = nullptr;
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#endif
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}
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#if !RADIOLIB_EXCLUDE_AFSK
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FSK4Client::FSK4Client(AFSKClient* audio) {
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phyLayer = audio->phyLayer;
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audioClient = audio;
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}
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#endif
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int16_t FSK4Client::begin(float base, uint32_t shift, uint16_t rate) {
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// save configuration
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baseFreqHz = base;
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shiftFreqHz = shift;
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// calculate duration of 1 bit
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bitDuration = (RadioLibTime_t)1000000/rate;
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// calculate carrier shift
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shiftFreq = getRawShift(shift);
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// Write resultant tones into arrays for quick lookup when modulating.
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for(uint8_t i = 0; i < 4; i++) {
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tones[i] = shiftFreq*i;
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tonesHz[i] = shiftFreqHz*i;
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}
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// calculate 24-bit frequency
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baseFreq = (base * 1000000.0) / phyLayer->getFreqStep();
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// configure for direct mode
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return(phyLayer->startDirect());
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}
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void FSK4Client::idle() {
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// Idle at Tone 0.
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tone(0);
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}
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int16_t FSK4Client::setCorrection(int16_t offsets[], float length) {
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for(uint8_t i = 0; i < 4; i++) {
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tones[i] += getRawShift(offsets[i]);
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tonesHz[i] += offsets[i];
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}
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bitDuration *= length;
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return(RADIOLIB_ERR_NONE);
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}
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size_t FSK4Client::write(uint8_t* buff, size_t len) {
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size_t n = 0;
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for(size_t i = 0; i < len; i++) {
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n += FSK4Client::write(buff[i]);
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}
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FSK4Client::standby();
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return(n);
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}
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size_t FSK4Client::write(uint8_t b) {
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// send symbols MSB first
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for(uint8_t i = 0; i < 4; i++) {
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// Extract 4FSK symbol (2 bits)
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uint8_t symbol = (b & 0xC0) >> 6;
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// Modulate
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FSK4Client::tone(symbol);
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// Shift to next symbol
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b = b << 2;
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}
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return(1);
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}
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void FSK4Client::tone(uint8_t i) {
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Module* mod = phyLayer->getMod();
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RadioLibTime_t start = mod->hal->micros();
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transmitDirect(baseFreq + tones[i], baseFreqHz + tonesHz[i]);
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mod->waitForMicroseconds(start, bitDuration);
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}
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int16_t FSK4Client::transmitDirect(uint32_t freq, uint32_t freqHz) {
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#if !RADIOLIB_EXCLUDE_AFSK
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if(audioClient != nullptr) {
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return(audioClient->tone(freqHz));
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}
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#endif
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return(phyLayer->transmitDirect(freq));
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}
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int16_t FSK4Client::standby() {
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// ensure everything is stopped in interrupt timing mode
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Module* mod = phyLayer->getMod();
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mod->waitForMicroseconds(0, 0);
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#if !RADIOLIB_EXCLUDE_AFSK
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if(audioClient != nullptr) {
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return(audioClient->noTone());
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}
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#endif
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return(phyLayer->standby());
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}
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int32_t FSK4Client::getRawShift(int32_t shift) {
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// calculate module carrier frequency resolution
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int32_t step = round(phyLayer->getFreqStep());
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// check minimum shift value
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if(RADIOLIB_ABS(shift) < step / 2) {
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return(0);
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}
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// round shift to multiples of frequency step size
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if(RADIOLIB_ABS(shift) % step < (step / 2)) {
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return(shift / step);
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}
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if(shift < 0) {
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return((shift / step) - 1);
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}
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return((shift / step) + 1);
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}
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#endif
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