64 lines
2.0 KiB
C++
64 lines
2.0 KiB
C++
#include <Arduino.h>
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#include <driver/i2s.h>
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// you shouldn't need to change these settings
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#define SAMPLE_BUFFER_SIZE 512
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#define SAMPLE_RATE 8000
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// most microphones will probably default to left channel but you may need to tie the L/R pin low
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#define I2S_MIC_CHANNEL I2S_CHANNEL_FMT_ONLY_LEFT
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// either wire your microphone to the same pins or change these to match your wiring
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#define I2S_MIC_SERIAL_CLOCK 8
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#define I2S_MIC_LEFT_RIGHT_CLOCK 9
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#define I2S_MIC_SERIAL_DATA 10
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// don't mess around with this
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i2s_config_t i2s_config = {
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.mode = (i2s_mode_t)(I2S_MODE_MASTER | I2S_MODE_RX),
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.sample_rate = SAMPLE_RATE,
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.bits_per_sample = I2S_BITS_PER_SAMPLE_32BIT,
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.channel_format = I2S_CHANNEL_FMT_ONLY_LEFT,
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.communication_format = I2S_COMM_FORMAT_I2S,
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.intr_alloc_flags = ESP_INTR_FLAG_LEVEL1,
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.dma_buf_count = 4,
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.dma_buf_len = 1024,
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.use_apll = false,
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.tx_desc_auto_clear = false,
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.fixed_mclk = 0};
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// and don't mess around with this
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i2s_pin_config_t i2s_mic_pins = {
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.bck_io_num = I2S_MIC_SERIAL_CLOCK,
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.ws_io_num = I2S_MIC_LEFT_RIGHT_CLOCK,
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.data_out_num = I2S_PIN_NO_CHANGE,
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.data_in_num = I2S_MIC_SERIAL_DATA};
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void setup()
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{
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// we need serial output for the plotter
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Serial.begin(115200);
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// start up the I2S peripheral
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i2s_driver_install(I2S_NUM_0, &i2s_config, 0, NULL);
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i2s_set_pin(I2S_NUM_0, &i2s_mic_pins);
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}
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int32_t raw_samples[SAMPLE_BUFFER_SIZE];
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void loop()
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{
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// read from the I2S device
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size_t bytes_read = 0;
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i2s_read(I2S_NUM_0, raw_samples, sizeof(int32_t) * SAMPLE_BUFFER_SIZE, &bytes_read, portMAX_DELAY);
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int samples_read = bytes_read / sizeof(int32_t);
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// dump the samples out to the serial channel.
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for (int i = 0; i < samples_read; i++)
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{
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// False print statements to "lock range" on serial plotter display
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// Change rangelimit value to adjust "sensitivity"
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int rangelimit = 2000000;
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Serial.print(rangelimit * -1);
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Serial.print(" ");
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Serial.print(rangelimit);
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Serial.print(" ");
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Serial.printf("%ld\n", raw_samples[i]);
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}
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} |