How to Configure ESP32 I2S for Audio Playback and Microphone Input

Configuring ESP32 I2S for Simultaneous Audio Playback and Microphone Input

The ESP32 is a powerful microcontroller that supports I2S audio capabilities. In this tutorial, we will configure the ESP32 to handle simultaneous audio playback and microphone input using PCM format at 16-bit, 44.1kHz. This setup is ideal for projects requiring audio processing, such as voice recognition or music playback with live input.

Prerequisites

• Basic knowledge of Arduino programming
• ESP32 development board
• I2S microphone (e.g., INMP441)
• I2S DAC or audio output module (e.g., PCM5102A)
• Arduino IDE installed on your computer
• ESP32 board package installed in Arduino IDE

Parts/Tools

• ESP32 development board
• INMP441 I2S microphone
• PCM5102A I2S DAC
• Jumper wires
• Computer with Arduino IDE

Steps

1. Wiring the Components
   1. Connect the INMP441 microphone to the ESP32:
      • VCC (Microphone) to 3.3V (ESP32)
      • GND (Microphone) to GND (ESP32)
      • BCK (Microphone) to GPIO 26 (ESP32)
      • WS (Microphone) to GPIO 25 (ESP32)
      • DATA (Microphone) to GPIO 22 (ESP32)
   2. Connect the PCM5102A DAC to the ESP32:
      • VCC (DAC) to 5V (ESP32)
      • GND (DAC) to GND (ESP32)
      • BCK (DAC) to GPIO 26 (ESP32)
      • WS (DAC) to GPIO 25 (ESP32)
      • DATA (DAC) to GPIO 21 (ESP32)
2. Setting Up the Arduino IDE
   1. Open Arduino IDE and go to File > Preferences.
   2. Add the following URL to the Additional Boards Manager URLs field:

      https://dl.espressif.com/dl/package_esp32_index.json

   3. Go to Tools > Board > Boards Manager and install the ESP32 package.
3. Programming the ESP32
   1. Create a new sketch and include the necessary libraries:

      #include 
      #include 
                      

   2. Set up the I2S configuration for both playback and input:

      void setup() {
          Serial.begin(115200);
          
          // I2S configuration
          i2s_config_t i2s_config = {
              .mode = (i2s_mode_t)(I2S_MODE_MASTER | I2S_MODE_TX | I2S_MODE_RX),
              .sample_rate = 44100,
              .bits_per_sample = I2S_BITS_PER_SAMPLE_16BIT,
              .channel_format = I2S_CHANNEL_FMT_RIGHT_LEFT,
              .communication_format = I2S_COMM_FORMAT_I2S,
              .intr_alloc = 0,
              .dma_buf_count = 8,
              .dma_buf_len = 1024,
          };
          
          // I2S pins
          i2s_pin_config_t pin_config = {
              .bck_io_num = 26,
              .ws_io_num = 25,
              .data_out_num = 21,
              .data_in_num = 22,
          };
          
          // Install I2S driver
          i2s_driver_install(I2S_NUM_0, &i2s_config, 0, NULL);
          i2s_set_pin(I2S_NUM_0, &pin_config);
      }
                      

   3. Read audio data from the microphone and output it to the DAC:

      void loop() {
          int bytes_read = 0;
          uint8_t buffer[1024];
      
          // Read data from microphone
          i2s_read(I2S_NUM_0, &buffer, sizeof(buffer), &bytes_read, portMAX_DELAY);
          
          // Write data to DAC
          i2s_write(I2S_NUM_0, &buffer, bytes_read, &bytes_written, portMAX_DELAY);
      }
                      

4. Upload the Code
   1. Select the correct board and port under Tools.
   2. Click on the upload button to compile and upload the code to the ESP32.

Troubleshooting

• No audio output: Check wiring connections and ensure that the DAC is powered properly.
• Microphone not detected: Ensure that the microphone is connected to the correct GPIO pins.
• Distorted audio: Verify the sample rate and bit depth in your configuration match the specifications of your hardware.

Conclusion

In this tutorial, we successfully configured the ESP32 to handle simultaneous audio playback and microphone input using I2S in PCM format at 16-bit, 44.1kHz. This setup opens up many possibilities for audio processing applications. Experiment with different audio sources and processing techniques to expand your project’s capabilities.