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300 baud demodulator implemented

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Mark Qvist 2019-01-08 11:10:21 +01:00
parent 7f5fe36cc2
commit 00dcf5a300
2 changed files with 29 additions and 13 deletions
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35
hardware/AFSK.h
View File

@ -46,10 +46,10 @@ inline static uint8_t sinSample(uint16_t i) {
#define CONFIG_AFSK_TRAILER_LEN 25UL
#define BIT_STUFF_LEN 5
#define BITRATE 300
#define BITRATE 1200
#if BITRATE == 300
#define CONFIG_ADC_SAMPLERATE 4800UL
#define CONFIG_ADC_SAMPLERATE 9600UL
#define CONFIG_DAC_SAMPLERATE 19200UL
#elif BITRATE == 1200
#define CONFIG_ADC_SAMPLERATE 9600UL
@ -78,8 +78,14 @@ inline static uint8_t sinSample(uint16_t i) {
#define SIGNAL_TRANSITIONED(bits) DUAL_XOR((bits), (bits) >> 2)
#endif
// TODO: Calculate based on sample rate [Done?]
#define PHASE_BITS 8 // Sub-sample phase counter resolution
#if BITRATE == 300
// TODO: Real-world tests on which resolution is best
//#define PHASE_BITS 8
#define PHASE_BITS 4
#else
#define PHASE_BITS 8 // Sub-sample phase counter resolution
#endif
#define PHASE_INC 1 // Nudge by above resolution for each adjustment
#define PHASE_MAX (ADC_SAMPLESPERBIT * PHASE_BITS) // Size of our phase counter
@ -98,9 +104,16 @@ inline static uint8_t sinSample(uint16_t i) {
#define PHASE_THRESHOLD (PHASE_MAX / 2) // Target transition point of our phase window
#endif
#define DCD_TIMEOUT_SAMPLES CONFIG_ADC_SAMPLERATE/100
#define DCD_MIN_COUNT CONFIG_ADC_SAMPLERATE/1600
#if BITRATE == 300
#define DCD_TIMEOUT_SAMPLES 520
#define DCD_MIN_COUNT 2
#elif BITRATE == 1200
#define DCD_TIMEOUT_SAMPLES CONFIG_ADC_SAMPLERATE/100
#define DCD_MIN_COUNT CONFIG_ADC_SAMPLERATE/1600
#elif BITRATE == 2400
#define DCD_TIMEOUT_SAMPLES CONFIG_ADC_SAMPLERATE/100
#define DCD_MIN_COUNT CONFIG_ADC_SAMPLERATE/1600
#endif
// TODO: Revamp filtering
#if BITRATE == 1200
@ -116,7 +129,7 @@ inline static uint8_t sinSample(uint16_t i) {
//#define MARK_FREQ 2200
//#define SPACE_FREQ 4000
#elif BITRATE == 300
#define FILTER_CUTOFF 600
#define FILTER_CUTOFF 500
#define MARK_FREQ 1600
#define SPACE_FREQ 1800
#else
@ -154,7 +167,7 @@ typedef struct Afsk
uint16_t phaseAcc; // Phase accumulator
uint16_t phaseInc; // Phase increment per sample
uint8_t silentSamples; // How many samples were completely silent
uint16_t silentSamples; // How many samples were completely silent
FIFOBuffer txFifo; // FIFO for transmit data
uint8_t txBuf[CONFIG_AFSK_TX_BUFLEN]; // Actual data storage for said FIFO
@ -169,7 +182,7 @@ typedef struct Afsk
#elif BITRATE == 2400
int8_t delayBuf[7 + 1];
#elif BITRATE == 300
int8_t delayBuf[ADC_SAMPLESPERBIT / 2 + 1];
int8_t delayBuf[16 + 1];
#endif
FIFOBuffer rxFifo; // FIFO for received data
@ -180,6 +193,8 @@ typedef struct Afsk
#if ADC_SAMPLESPERBIT < 17
uint16_t sampledBits; // Bits sampled by the demodulator (at ADC speed)
#elif ADC_SAMPLESPERBIT < 33
uint32_t sampledBits;
#else
#error Not enough space in sampledBits variable!
#endif

7
protocol/KISS.c
View File

@ -28,10 +28,10 @@ void kiss_init(AX25Ctx *ax25, Afsk *afsk, Serial *ser) {
}
// TODO: Remove debug functions
// size_t decodes = 0;
//size_t decodes = 0;
void kiss_messageCallback(AX25Ctx *ctx) {
// decodes++;
// printf("%d\r\n", decodes);
//decodes++;
//printf("%d\r\n", decodes);
fputc(FEND, &serial->uart0);
fputc(0x00, &serial->uart0);
@ -48,6 +48,7 @@ void kiss_messageCallback(AX25Ctx *ctx) {
}
}
fputc(FEND, &serial->uart0);
}
void kiss_csma(AX25Ctx *ctx, uint8_t *buf, size_t len) {