OVMS3-idf/examples/peripherals/i2s/main/i2s_example_main.c
Tuan PM fc1ee2666a I2S: fixed support for 24 and 32-bits, fixed tx/rx at the same time and others in log:
Add support 24, 32 bits

@jxmao optimize i2s_zero_buffer

@jxmao correct config support slave mode

@jxmao correct setup pin support tx/rx at the same time

Enhance pin power

@jxmao add dynamic change number of channels

remove nvs_init

remove start log and enhance power pin setup

using enum for i2s_channel and i2s_bits_per_sample, return ESP_ERR_INVALID_ARG when check params

validate i2s_bits_per_sample and channel

check tx & rx buffer before fill zero

remove checking channel as @jxmao suggest

limit dma buffer

modify i2s pin back to gpio mux before configure gpio matrix, resolve github issue #512

Add support 24, 32 bits

reduce push function

Modify sample can test with 24, 32-bits

Add i2s sample README

Fixed i2s_set_clk got reset sometime

can changes bit-wide while running

Fix sample rate calculation for DAC mode from @jeroen

modify example can change bits per sample every 5 seconds

cleanup

add comment for bytes_per_sample

update as @angus suggestions

Add i2s_set_clk api

I2S driver bug fixed as following log:

@jxmao optimize i2s_zero_buffer

@jxmao correct config support slave mode

@jxmao correct setup pin support tx/rx at the same time

Enhance pin power

@jxmao add dynamic change number of channels

remove nvs_init

remove start log and enhance power pin setup

using enum for i2s_channel and i2s_bits_per_sample, return ESP_ERR_INVALID_ARG when check params

validate i2s_bits_per_sample and channel

check tx & rx buffer before fill zero

remove checking channel as @jxmao suggest

limit dma buffer

modify i2s pin back to gpio mux before configure gpio matrix, resolve github issue #512

limit dma buffer to 4092

change gpio_matrix_*_check to inline function, remove some comments and rename test_i2s function to setup_triangle_sine_waves

for change commit title
2017-04-27 10:00:10 +07:00

111 lines
3.9 KiB
C

/* I2S Example
This example code will output 100Hz sine wave and triangle wave to 2-channel of I2S driver
Every 5 seconds, it will change bits_per_sample [16, 24, 32] for i2s data
This example code is in the Public Domain (or CC0 licensed, at your option.)
Unless required by applicable law or agreed to in writing, this
software is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
CONDITIONS OF ANY KIND, either express or implied.
*/
#include <stdio.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "driver/i2s.h"
#include "esp_system.h"
#include <math.h>
#define SAMPLE_RATE (36000)
#define I2S_NUM (0)
#define WAVE_FREQ_HZ (100)
#define PI 3.14159265
#define SAMPLE_PER_CYCLE (SAMPLE_RATE/WAVE_FREQ_HZ)
static void setup_triangle_sine_waves(int bits)
{
int *samples_data = malloc(((bits+8)/16)*SAMPLE_PER_CYCLE*4);
unsigned int i, sample_val;
double sin_float, triangle_float, triangle_step = (double) pow(2, bits) / SAMPLE_PER_CYCLE;
printf("\r\nTest bits=%d free mem=%d, written data=%d\n", bits, esp_get_free_heap_size(), ((bits+8)/16)*SAMPLE_PER_CYCLE*4);
triangle_float = -(pow(2, bits)/2 - 1);
for(i = 0; i < SAMPLE_PER_CYCLE; i++) {
sin_float = sin(i * PI / 180.0);
if(sin_float >= 0)
triangle_float += triangle_step;
else
triangle_float -= triangle_step;
sin_float *= (pow(2, bits)/2 - 1);
if (bits == 16) {
sample_val = 0;
sample_val += (short)triangle_float;
sample_val = sample_val << 16;
sample_val += (short) sin_float;
samples_data[i] = sample_val;
} else if (bits == 24) { //1-bytes unused
samples_data[i*2] = ((int) triangle_float) << 8;
samples_data[i*2 + 1] = ((int) sin_float) << 8;
} else {
samples_data[i*2] = ((int) triangle_float);
samples_data[i*2 + 1] = ((int) sin_float);
}
}
i2s_set_clk(I2S_NUM, SAMPLE_RATE, bits, 2);
//Using push
// for(i = 0; i < SAMPLE_PER_CYCLE; i++) {
// if (bits == 16)
// i2s_push_sample(0, &samples_data[i], 100);
// else
// i2s_push_sample(0, &samples_data[i*2], 100);
// }
// or write
i2s_write_bytes(I2S_NUM, (const char *)samples_data, ((bits+8)/16)*SAMPLE_PER_CYCLE*4, 100);
free(samples_data);
}
void app_main()
{
//for 36Khz sample rates, we create 100Hz sine wave, every cycle need 36000/100 = 360 samples (4-bytes or 8-bytes each sample)
//depend on bits_per_sample
//using 6 buffers, we need 60-samples per buffer
//if 2-channels, 16-bit each channel, total buffer is 360*4 = 1440 bytes
//if 2-channels, 24/32-bit each channel, total buffer is 360*8 = 2880 bytes
i2s_config_t i2s_config = {
.mode = I2S_MODE_MASTER | I2S_MODE_TX, // Only TX
.sample_rate = SAMPLE_RATE,
.bits_per_sample = 16,
.channel_format = I2S_CHANNEL_FMT_RIGHT_LEFT, //2-channels
.communication_format = I2S_COMM_FORMAT_I2S | I2S_COMM_FORMAT_I2S_MSB,
.dma_buf_count = 6,
.dma_buf_len = 60, //
.intr_alloc_flags = ESP_INTR_FLAG_LEVEL1 //Interrupt level 1
};
i2s_pin_config_t pin_config = {
.bck_io_num = 26,
.ws_io_num = 25,
.data_out_num = 22,
.data_in_num = -1 //Not used
};
i2s_driver_install(I2S_NUM, &i2s_config, 0, NULL);
i2s_set_pin(I2S_NUM, &pin_config);
int test_bits = 16;
while (1) {
setup_triangle_sine_waves(test_bits);
vTaskDelay(5000/portTICK_RATE_MS);
test_bits += 8;
if(test_bits > 32)
test_bits = 16;
}
}