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Variable bitrate experiment

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Mark Qvist 2015-04-24 10:47:50 +02:00
parent 095a558fcb
commit 8d9da446a4
2 changed files with 44 additions and 7 deletions
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26
hardware/AFSK.h
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@ -45,17 +45,33 @@ inline static uint8_t sinSample(uint16_t i) {
#define CONFIG_AFSK_PREAMBLE_LEN 150UL
#define CONFIG_AFSK_TRAILER_LEN 50UL
#define SAMPLERATE 9600
#define BITRATE 1200
#define BITRATE 1600
#if BITRATE == 960
#define FILTER_CUTOFF 600
#define MARK_FREQ 1300
#define SPACE_FREQ 2100
#define PHASE_BITS 8 // How much to increment phase counter each sample
#if BITRATE == 1200
#define FILTER_CUTOFF 600
#define MARK_FREQ 1200
#define SPACE_FREQ 2200
#define PHASE_BITS 8
#elif BITRATE == 1600
#define FILTER_CUTOFF 800
#define MARK_FREQ 1600
#define SPACE_FREQ 2800
#define PHASE_BITS 6
#else
#error Unsupported bitrate!
#endif
#define SAMPLESPERBIT (SAMPLERATE / BITRATE)
#define BIT_STUFF_LEN 5
#define MARK_FREQ 1200
#define SPACE_FREQ 2200
#define PHASE_BITS 8 // How much to increment phase counter each sample
#define PHASE_INC 1 // Nudge by an eigth of a sample each adjustment
#define PHASE_MAX (SAMPLESPERBIT * PHASE_BITS) // Resolution of our phase counter = 64
#define PHASE_THRESHOLD (PHASE_MAX / 2) // Target transition point of our phase window
typedef struct Hdlc
{
uint8_t demodulatedBits;