mordae/pico-sdr
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Use uint32_t freq

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This commit is contained in:
Jan Hamal Dvořák 2025-07-03 16:12:24 +02:00
parent 2fdc334719
commit 1e4846dac3
1 changed files with 11 additions and 18 deletions

29
src/main.c
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@ -16,7 +16,6 @@
#include <hardware/regs/clocks.h>
#include <hardware/structs/bus_ctrl.h>
#include <math.h>
#include <stdio.h>
#include <limits.h>
#include <stdlib.h>
@ -225,7 +224,7 @@ static void init_adder()
origin_adder = pio_add_program(PIO, &prog);
pio_sm_config pc = pio_get_default_sm_config();
sm_config_set_wrap(&pc, origin_adder, origin_adder + 13);
sm_config_set_wrap(&pc, origin_adder, origin_adder + 15);
sm_config_set_clkdiv_int_frac(&pc, 1, 0);
sm_config_set_in_shift(&pc, false, true, 32);
sm_config_set_out_shift(&pc, false, true, 32);
@ -234,13 +233,11 @@ static void init_adder()
pio_sm_init(PIO, SM_SIN, origin_adder, &pc);
}
#define STEP_BASE ((UINT_MAX + 1.0) / CLK_SYS_HZ)
static void lo_generate_phase(uint32_t *buf, size_t len, uint32_t step, uint32_t phase)
{
for (size_t i = 0; i < len; i++) {
uint32_t bits = 0;
uint32_t bits = 0;
for (size_t i = 0; i < len; i++) {
for (int j = 0; j < 32; j++) {
bits <<= 1;
bits |= phase >> 31;
@ -251,16 +248,12 @@ static void lo_generate_phase(uint32_t *buf, size_t len, uint32_t step, uint32_t
}
}
static void rx_lo_init(double req_freq, bool align)
static void rx_lo_init(uint32_t freq)
{
const double step_hz = (double)CLK_SYS_HZ / ((8 << LO_BITS_DEPTH) / 2.0);
double freq = req_freq;
if (align)
freq = round(freq / step_hz) * step_hz;
uint32_t step = STEP_BASE * freq;
const uint32_t frac = (8 + 16llu * CLK_SYS_HZ / (8 << LO_BITS_DEPTH)) >> 4;
uint32_t step = ((uint64_t)freq << 32) / (uint64_t)CLK_SYS_HZ;
step /= frac;
step *= frac;
lo_generate_phase(lo_cos, LO_WORDS, step, COS_PHASE);
lo_generate_phase(lo_sin, LO_WORDS, step, SIN_PHASE);
}
@ -535,13 +528,13 @@ static void run_command(uint8_t cmd, uint32_t arg)
if (0x01 == cmd) {
/* Tune to a new center frequency */
frequency = arg;
rx_lo_init(frequency + sample_rate, true);
rx_lo_init(frequency + sample_rate);
} else if (0x02 == cmd) {
/* Set the rate at which IQ sample pairs are sent */
sample_rate = arg;
gain = BASE_GAIN / (CLK_SYS_HZ / sample_rate / 2);
dma_timer_set_fraction(dma_t_samp, 1, CLK_SYS_HZ / (sample_rate * DECIMATE));
rx_lo_init(frequency + sample_rate, true);
rx_lo_init(frequency + sample_rate);
}
}
@ -632,7 +625,7 @@ int main()
queue_init(&iq_queue, sizeof(uint8_t *), IQ_QUEUE_LEN);
rx_lo_init(frequency + sample_rate, true);
rx_lo_init(frequency + sample_rate);
/* We need to have the sampling timer ready. */
dma_t_samp = dma_claim_unused_timer(true);