demo of driving MAX2719 dot matrix displays with STM32F103 Bluepill
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f103-dotmatrix/project/mode_audio.c

159 lines
3.5 KiB

#include "mode_audio.h"
#include <arm_math.h>
#include "bus/event_queue.h"
#include "dotmatrix.h"
bool audio_mode_active = true;
static volatile bool capture_pending = false;
static volatile bool print_next_fft = false;
static float virt_zero_value = 2045.0f;
#define SAMP_BUF_LEN 256
union samp_buf_union {
uint32_t uints[SAMP_BUF_LEN];
float floats[SAMP_BUF_LEN];
uint8_t as_bytes[SAMP_BUF_LEN*sizeof(uint32_t)];
};
// sample buffers (static - invalidated when sampling starts anew).
static union samp_buf_union samp_buf;
// prototypes
static void audio_capture_done(void* unused);
static void start_adc_dma(uint32_t *memory, uint32_t count)
{
ADC_Cmd(ADC1, DISABLE);
DMA_DeInit(DMA1_Channel1);
DMA_InitTypeDef dma_cnf;
dma_cnf.DMA_PeripheralBaseAddr = (uint32_t)&ADC1->DR;
dma_cnf.DMA_MemoryBaseAddr = (uint32_t)memory;
dma_cnf.DMA_DIR = DMA_DIR_PeripheralSRC;
dma_cnf.DMA_BufferSize = count;
dma_cnf.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
dma_cnf.DMA_MemoryInc = DMA_MemoryInc_Enable;
dma_cnf.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Word;
dma_cnf.DMA_MemoryDataSize = DMA_MemoryDataSize_Word;
dma_cnf.DMA_Mode = DMA_Mode_Normal;
dma_cnf.DMA_Priority = DMA_Priority_Low;
dma_cnf.DMA_M2M = DMA_M2M_Disable;
DMA_Init(DMA1_Channel1, &dma_cnf);
DMA_ITConfig(DMA1_Channel1, DMA1_IT_TC1, ENABLE);
ADC_Cmd(ADC1, ENABLE);
ADC_DMACmd(ADC1, ENABLE);
DMA_Cmd(DMA1_Channel1, ENABLE);
TIM_Cmd(TIM3, ENABLE);
}
void DMA1_Channel1_IRQHandler(void)
{
DMA_ClearITPendingBit(DMA1_IT_TC1);
DMA_ClearITPendingBit(DMA1_IT_TE1);
DMA_DeInit(DMA1_Channel1);
TIM_Cmd(TIM3, DISABLE);
ADC_DMACmd(ADC1, DISABLE);
if (audio_mode_active) {
tq_post(audio_capture_done, NULL);
} else {
// unset 'pending'
capture_pending = false;
}
}
static void audio_capture_done(void* unused)
{
(void)unused;
const int samp_count = SAMP_BUF_LEN/2;
const int bin_count = SAMP_BUF_LEN/4;
float *bins = samp_buf.floats;
// Convert to floats
for (int i = 0; i < samp_count; i++) {
samp_buf.floats[i] = (float)samp_buf.uints[i];
}
// normalize
float mean;
arm_mean_f32(samp_buf.floats, samp_count, &mean);
virt_zero_value = mean;
for (int i = 0; i < samp_count; i++) {
samp_buf.floats[i] -= virt_zero_value;
}
if (print_next_fft) {
printf("--- Raw (adjusted) ---\n");
for(int i = 0; i < samp_count; i++) {
printf("%.2f, ", samp_buf.floats[i]);
}
printf("\n");
}
for (int i = samp_count - 1; i >= 0; i--) {
bins[i * 2 + 1] = 0; // imaginary
bins[i * 2] = samp_buf.floats[i]; // real
}
const arm_cfft_instance_f32 *S;
S = &arm_cfft_sR_f32_len128;
arm_cfft_f32(S, bins, 0, true); // bit reversed FFT
arm_cmplx_mag_f32(bins, bins, bin_count); // get magnitude (extract real values)
if (print_next_fft) {
printf("--- Bins ---\n");
for(int i = 0; i < bin_count; i++) {
printf("%.2f, ", bins[i]);
}
printf("\n");
}
// normalize
dmtx_clear(dmtx);
float factor = (1.0f/bin_count)*0.2f;
for(int i = 0; i < bin_count-1; i+=2) {
bins[i] *= factor;
bins[i+1] *= factor;
//float avg = i==0 ? bins[1] : (bins[i] + bins[i+1])/2;
float avg = (bins[i] + bins[i+1])/2;
for(int j = 0; j < 1+floorf(avg); j++) {
//dmtx_toggle(dmtx, i/2, j);
dmtx_toggle(dmtx, i/2, j);
//dmtx_toggle(dmtx, j, 15-i/2);
//dmtx_toggle(dmtx, 15- i/2, 15-j);
}
}
dmtx_show(dmtx);
print_next_fft = false;
capture_pending = false;
}
void capture_audio(void *unused)
{
(void)unused;
if (capture_pending) return;
if (! audio_mode_active) return;
capture_pending = true;
start_adc_dma(samp_buf.uints, SAMP_BUF_LEN/2);
}