// Connections to INMP441 I2S microphone
#define I2S_WS 15
#define I2S_SD 32
#define I2S_SCK 14
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/* ESP32 I2S Microphone Sample esp32-i2s-mic-sample.ino Sample sound from I2S microphone, display on Serial Plotter Requires INMP441 I2S microphone DroneBot Workshop 2022 https://dronebotworkshop.com */ // Include I2S driver #include <driver/i2s.h> // Connections to INMP441 I2S microphone #define I2S_WS 15 #define I2S_SD 32 #define I2S_SCK 14 // Use I2S Processor 0 #define I2S_PORT I2S_NUM_0 // Define input buffer length #define bufferLen 64 int16_t sBuffer[bufferLen]; void i2s_install() { // Set up I2S Processor configuration const i2s_config_t i2s_config = { .mode = i2s_mode_t(I2S_MODE_MASTER | I2S_MODE_RX), .sample_rate = 8000, //44100, .bits_per_sample = i2s_bits_per_sample_t(8), .channel_format = I2S_CHANNEL_FMT_ONLY_LEFT, .communication_format = i2s_comm_format_t(I2S_COMM_FORMAT_STAND_I2S), .intr_alloc_flags = 0, .dma_buf_count = 8, .dma_buf_len = bufferLen, .use_apll = false }; i2s_driver_install(I2S_PORT, &i2s_config, 0, NULL); } void i2s_setpin() { // Set I2S pin configuration const i2s_pin_config_t pin_config = { .bck_io_num = I2S_SCK, .ws_io_num = I2S_WS, .data_out_num = -1, .data_in_num = I2S_SD }; i2s_set_pin(I2S_PORT, &pin_config); } void setup() { // Set up Serial Monitor Serial.begin(115200); Serial.println(" "); delay(1000); // Set up I2S i2s_install(); i2s_setpin(); i2s_start(I2S_PORT); delay(500); } void loop() { // False print statements to "lock range" on serial plotter display // Change rangelimit value to adjust "sensitivity" int rangelimit = 3000; Serial.print(rangelimit * -1); Serial.print(" "); Serial.print(rangelimit); Serial.print(" "); // Get I2S data and place in data buffer size_t bytesIn = 0; esp_err_t result = i2s_read(I2S_PORT, &sBuffer, bufferLen, &bytesIn, portMAX_DELAY); if (result == ESP_OK) { // Read I2S data buffer int16_t samples_read = bytesIn / 8; if (samples_read > 0) { float mean = 0; for (int16_t i = 0; i < samples_read; ++i) { mean += (sBuffer[i]); } // Average the data reading mean /= samples_read; // Print to serial plotter Serial.println(mean); } } } |