sample rate

src/main.cpp

@@ -1,16 +1,116 @@
+/*
+  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 <Arduino.h>
-const int potPin = 33;
-//la valeur du potentiomètre
+// Include I2S driver
+#include <driver/i2s.h>
 
-int potvalue=0;
+// Connections to INMP441 I2S microphone
+#define I2S_WS 25
+#define I2S_SD 33
+#define I2S_SCK 32
 
-void setup() {
-pinMode(potPin,INPUT);
-Serial.begin(9600);
+// Use I2S Processor 0
+#define I2S_PORT I2S_NUM_0
 
+// Define input buffer length
+#define bufferLen 1024
+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 = 44100,
+        .bits_per_sample = i2s_bits_per_sample_t(16),
+        .channel_format = I2S_CHANNEL_FMT_ONLY_LEFT,
+        .communication_format = i2s_comm_format_t(I2S_COMM_FORMAT_STAND_I2S),
+        .intr_alloc_flags = ESP_INTR_FLAG_LEVEL1,
+        .dma_buf_count = 4,
+        .dma_buf_len = bufferLen,
+        .use_apll = false,
+        .tx_desc_auto_clear = false,
+        .fixed_mclk = 0};
+
+    i2s_driver_install(I2S_PORT, &i2s_config, 0, NULL);
 }
-void loop() {
 
-//mesure la valeur du potentiomtre
-potvalue=analogRead (potPin);
-Serial.println (potvalue);}
+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);
+
+            int recu = bytesIn / sizeof(int32_t);
+            for (int i = 0; i < recu; i++)
+            {
+                Serial.printf("%ld\n", sBuffer[i]);
+            }
+            // Serial.print(" - ");
+            Serial.println(bytesIn);
+        }
+    }
+}