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Implemented selectable data rates

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Mark Qvist 2015-04-26 18:15:05 +02:00
parent 8d9da446a4
commit b3fb6cc35e
2 changed files with 35 additions and 12 deletions
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20
hardware/AFSK.c
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@ -340,8 +340,16 @@ void AFSK_adc_isr(Afsk *afsk, int8_t currentSample) {
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) / 2.899043379;
#elif FILTER_CUTOFF == 1200
afsk->iirX[1] = ((int8_t)fifo_pop(&afsk->delayFifo) * currentSample) >> 1;
// The above is a simplification of:
// afsk->iirX[1] = ((int8_t)fifo_pop(&afsk->delayFifo) * currentSample) / 2.228465666;
#elif FILTER_CUTOFF == 1600
afsk->iirX[1] = ((int8_t)fifo_pop(&afsk->delayFifo) * currentSample) >> 1;
// The above is a simplification of:
// afsk->iirX[1] = ((int8_t)fifo_pop(&afsk->delayFifo) * currentSample) / 1.881349100;
#else
#error Unsupported bitrate!
#error Unsupported filter cutoff!
#endif
afsk->iirY[0] = afsk->iirY[1];
@ -354,8 +362,16 @@ void AFSK_adc_isr(Afsk *afsk, int8_t currentSample) {
afsk->iirY[1] = afsk->iirX[0] + afsk->iirX[1] + (afsk->iirY[0] / 3);
// The above is a simplification of a first-order 800Hz chebyshev filter:
// afsk->iirY[1] = afsk->iirX[0] + afsk->iirX[1] + (afsk->iirY[0] * 0.3101172565);
#elif FILTER_CUTOFF == 1200
afsk->iirY[1] = afsk->iirX[0] + afsk->iirX[1] + (afsk->iirY[0] / 10);
// The above is a simplification of a first-order 800Hz chebyshev filter:
// afsk->iirY[1] = afsk->iirX[0] + afsk->iirX[1] + (afsk->iirY[0] * 0.1025215106);
#elif FILTER_CUTOFF == 1600
afsk->iirY[1] = afsk->iirX[0] + afsk->iirX[1] + -1*(afsk->iirY[0] / 17);
// The above is a simplification of a first-order 800Hz chebyshev filter:
// afsk->iirY[1] = afsk->iirX[0] + afsk->iirX[1] + (afsk->iirY[0] * -0.0630669239);
#else
#error Unsupported bitrate!
#error Unsupported filter cutoff!
#endif