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Mark Qvist 2018-12-31 13:24:28 +01:00
parent 56bed68143
commit 874689c602
4 changed files with 109 additions and 51 deletions
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92
hardware/AFSK.c
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@ -376,44 +376,67 @@ void AFSK_adc_isr(Afsk *afsk, int8_t currentSample) {
afsk->iirX[0] = afsk->iirX[1];
#if CONFIG_SAMPLERATE == 9600
#if FILTER_CUTOFF == 600
afsk->iirX[1] = ((int8_t)fifo_pop(&afsk->delayFifo) * currentSample) >> 2;
// The above is a simplification of:
// afsk->iirX[1] = ((int8_t)fifo_pop(&afsk->delayFifo) * currentSample) / 3.558147322;
#else
#error Unsupported filter cutoff!
#endif
#elif CONFIG_SAMPLERATE == 19200
#if FILTER_CUTOFF == 600
afsk->iirX[1] = ((int8_t)fifo_pop(&afsk->delayFifo) * currentSample) / 6;
#else
#error Unsupported filter cutoff!
#endif
#else
#error Unsupported samplerate!
#endif
#if FILTER_CUTOFF == 500
#define IIR_GAIN 4 // Really 4.082041675
#define IIR_POLE 2 // Really Y[0] * 0.5100490981
afsk->iirX[1] = ((int8_t)fifo_pop(&afsk->delayFifo) * currentSample) / IIR_GAIN;
afsk->iirY[0] = afsk->iirY[1];
afsk->iirY[1] = afsk->iirX[0] + afsk->iirX[1] + (afsk->iirY[0] / 2);
afsk->iirY[0] = afsk->iirY[1];
#if CONFIG_SAMPLERATE == 9600
#if FILTER_CUTOFF == 600
afsk->iirY[1] = afsk->iirX[0] + afsk->iirX[1] + (afsk->iirY[0] >> 1);
// The above is a simplification of:
// afsk->iirY[1] = afsk->iirX[0] + afsk->iirX[1] + (afsk->iirY[0] * 0.4379097269);
#else
#error Unsupported filter cutoff!
#endif
#elif CONFIG_SAMPLERATE == 19200
#if FILTER_CUTOFF == 600
afsk->iirY[1] = afsk->iirX[0] + afsk->iirX[1] + (afsk->iirY[0] / 2);
#if FILTER_CUTOFF == 150
#define IIR_GAIN 2 // Really 2.172813446e
#define IIR_POLE 2 // Really Y[0] * 0.9079534415
afsk->iirX[1] = ((int8_t)fifo_pop(&afsk->delayFifo) * currentSample) / IIR_GAIN;
afsk->iirY[0] = afsk->iirY[1];
afsk->iirY[1] = afsk->iirX[0] + afsk->iirX[1] + (afsk->iirY[0] / IIR_POLE);
#elif FILTER_CUTOFF == 500
#define IIR_GAIN 7 // Really 5.006847792
#define IIR_POLE 2 // Really Y[0] * 0.6005470741
afsk->iirX[1] = ((int8_t)fifo_pop(&afsk->delayFifo) * currentSample) / IIR_GAIN;
afsk->iirY[0] = afsk->iirY[1];
afsk->iirY[1] = afsk->iirX[0] + afsk->iirX[1] + (afsk->iirY[0] / IIR_POLE);
#elif FILTER_CUTOFF == 600
#define IIR_GAIN 6 // Really 6.166411713
#define IIR_POLE 2 // Really Y[0] * 0.6756622663
afsk->iirX[1] = ((int8_t)fifo_pop(&afsk->delayFifo) * currentSample) / IIR_GAIN;
afsk->iirY[0] = afsk->iirY[1];
afsk->iirY[1] = afsk->iirX[0] + afsk->iirX[1] + (afsk->iirY[0] / IIR_POLE);
#elif FILTER_CUTOFF == 772
#define IIR_GAIN 5 // Really 5.006847792
#define IIR_POLE 2 // Really Y[0] * 0.6005470741
afsk->iirX[1] = ((int8_t)fifo_pop(&afsk->delayFifo) * currentSample) / IIR_GAIN;
afsk->iirY[0] = afsk->iirY[1];
afsk->iirY[1] = afsk->iirX[0] + afsk->iirX[1] + (afsk->iirY[0] / IIR_POLE);
#elif FILTER_CUTOFF == 1000
#define IIR_GAIN 4 // Really 4.082041675
#define IIR_POLE 2 // Really Y[0] * 0.5100490981
afsk->iirX[1] = ((int8_t)fifo_pop(&afsk->delayFifo) * currentSample) / IIR_GAIN;
afsk->iirY[0] = afsk->iirY[1];
afsk->iirY[1] = afsk->iirX[0] + afsk->iirX[1] + (afsk->iirY[0] / IIR_POLE);
#elif FILTER_CUTOFF == 1400
#define IIR_GAIN 3 // Really 3.182326364
#define IIR_POLE 3 // Really Y[0] * 0.3715289474
afsk->iirX[1] = ((int8_t)fifo_pop(&afsk->delayFifo) * currentSample) / IIR_GAIN;
afsk->iirY[0] = afsk->iirY[1];
afsk->iirY[1] = afsk->iirX[0] + afsk->iirX[1] + (afsk->iirY[0] / IIR_POLE);
#else
#error Unsupported filter cutoff!
#endif
#else
#error Unsupported samplerate!
#error No filters defined for specified samplerate!
#endif
//int8_t freq_disc = (int8_t)fifo_pop(&afsk->delayFifo) * currentSample;
// We put the sampled bit in a delay-line:
// First we bitshift everything 1 left
@ -551,16 +574,13 @@ void AFSK_adc_isr(Afsk *afsk, int8_t currentSample) {
ISR(ADC_vect) {
TIFR1 = _BV(ICF1);
//DAC_PORT ^= 0xFF;
//DAC_PORT = ADCH;
AFSK_adc_isr(AFSK_modem, (ADCH - 128));
if (hw_afsk_dac_isr) {
DAC_PORT = AFSK_dac_isr(AFSK_modem);
LED_TX_ON();
} else {
// TODO: Enable full duplex if possible
AFSK_adc_isr(AFSK_modem, (ADCH - 128));
DAC_PORT = 127;
LED_TX_OFF();
}
@ -569,6 +589,10 @@ ISR(ADC_vect) {
/*
// TODO: Remove these debug sample collection functions
//DAC_PORT ^= 0xFF;
//DAC_PORT = ADCH;
if (capturedsamples == SAMPLES_TO_CAPTURE) {
printf("--- Dumping samples ---");
for (ticks_t i = 0; i < SAMPLES_TO_CAPTURE; i++) {