Git-Mirrors/OpenModem
1
0
Fork 0
mirror of https://github.com/markqvist/OpenModem.git synced 2025-05-20 07:10:21 -04:00
Code Issues Projects Releases Packages Wiki Activity Actions

Still working

Browse source
This commit is contained in:
Mark Qvist 2014-04-03 22:54:34 +02:00
parent 9b435bbd59
commit 73b8a6ed0b
5 changed files with 13 additions and 14 deletions
Download patch file Download diff file Expand all files Collapse all files

12
Modem/afsk.c
View file

@ -20,8 +20,8 @@
#define PHASE_BIT 8
#define PHASE_INC 1
#define PHASE_MAX (SAMPLEPERBIT * PHASE_BIT)
#define PHASE_THRES (PHASE_MAX / 2) // - PHASE_BIT / 2)
#define PHASE_MAX (SAMPLESPERBIT * PHASE_BIT)
#define PHASE_THRES (PHASE_MAX / 2)
// Modulator constants
#define MARK_FREQ 1200
@ -32,7 +32,7 @@
//Ensure sample rate is a multiple of bit rate
STATIC_ASSERT(!(CONFIG_AFSK_DAC_SAMPLERATE % BITRATE));
#define DAC_SAMPLEPERBIT (CONFIG_AFSK_DAC_SAMPLERATE / BITRATE)
#define DAC_SAMPLESPERBIT (CONFIG_AFSK_DAC_SAMPLERATE / BITRATE)
/**
* Sine table for the first quarter of wave.
@ -252,7 +252,7 @@ void afsk_adc_isr(Afsk *af, int8_t curr_sample)
* otherwise is a 0.
* This algorithm presumes that there are 8 samples per bit.
*/
STATIC_ASSERT(SAMPLEPERBIT == 8);
STATIC_ASSERT(SAMPLESPERBIT == 8);
uint8_t bits = af->sampled_bits & 0x07;
if (bits == 0x07 // 111, 3 bits set to 1
|| bits == 0x06 // 110, 2 bits
@ -405,7 +405,7 @@ uint8_t afsk_dac_isr(Afsk *af)
/* Go to the next bit */
af->tx_bit <<= 1;
}
af->sample_count = DAC_SAMPLEPERBIT;
af->sample_count = DAC_SAMPLESPERBIT;
}
/* Get new sample and put it out on the DAC */
@ -508,7 +508,7 @@ void afsk_init(Afsk *af, int adc_ch, int dac_ch)
fifo_init(&af->rx_fifo, af->rx_buf, sizeof(af->rx_buf));
/* Fill sample FIFO with 0 */
for (int i = 0; i < SAMPLEPERBIT / 2; i++)
for (int i = 0; i < SAMPLESPERBIT / 2; i++)
fifo_push(&af->delay_fifo, 0);
fifo_init(&af->tx_fifo, af->tx_buf, sizeof(af->tx_buf));