Git-Mirrors/OpenModem
1
0
Fork 0
mirror of https://github.com/markqvist/OpenModem.git synced 2025-06-19 20:04:21 -04:00
Code Issues Projects Releases Packages Wiki Activity Actions

300 baud modulator implemented

Browse source
This commit is contained in:
Mark Qvist 2019-01-07 13:41:49 +01:00
parent 3f5af2b26b
commit 7f5fe36cc2
2 changed files with 30 additions and 16 deletions
Download patch file Download diff file Expand all files Collapse all files

16
hardware/AFSK.c
View file

@ -399,13 +399,25 @@ void AFSK_adc_isr(Afsk *afsk, int8_t currentSample) {
afsk->iirX[0] = afsk->iirX[1];
#if CONFIG_ADC_SAMPLERATE == 9600
#if CONFIG_ADC_SAMPLERATE == 4800
#if FILTER_CUTOFF == 600
#define IIR_GAIN 2 // Really 2.228465666
#define IIR_POLE 10 // Really Y[0] * 0.1025215106
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
#elif CONFIG_ADC_SAMPLERATE == 9600
#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[1] = afsk->iirX[0] + afsk->iirX[1] + (afsk->iirY[0] / IIR_POLE);
#else
#error Unsupported filter cutoff!