Simple poc to show how to detect a i2c wm8978 codec in esp32 arduino.

detect_WM8978.ino

#include <Wire.h>

void setup() {
  // put your setup code here, to run once:
  Wire.begin( 21, 22, 400000 );
  Wire.beginTransmission( 0X1A );
  uint8_t error = Wire.endTransmission();
  if ( error ) ESP_LOGI( TAG, "No codec found." );
}

void loop() {
  // put your main code here, to run repeatedly:

}