/*
  I2C Scanner 
  
  Boardeinstellung in Arduino IDE
  ESP32 Wrover Module

  Ergebnis 19.3.2026

  Alle möglichen I2C pins probiert, kein Device Antwortet
  Scanning...
  No I2C devices found

 */
#include <Wire.h>

//#define IIC_CLK   27
//#define IIC_DATA  25

//#define IIC_CLK       32
//#define IIC_DATA      33


#define IIC_CLK       18
#define IIC_DATA      23

#define GPIO_PA_EN 21

void setup()
{
  Serial.begin(115200);
  pinMode(IIC_CLK, INPUT_PULLUP);  // Force ESP32 internal pull-ups
  pinMode(IIC_DATA, INPUT_PULLUP);
  //pinMode(0, OUTPUT); digitalWrite(0, HIGH); // Boot0 to power ES8388 codec
  // Enable amplifier
  //pinMode(GPIO_PA_EN, OUTPUT);
  //digitalWrite(GPIO_PA_EN, HIGH);
  Wire.begin(IIC_DATA, IIC_CLK);
  Wire.setClock(100000);  // Slow I2C to 100kHz for finicky codecs
  Serial.println("\nI2C Scanner with pullups + slow clock");
  
  //Wire.begin(IIC_DATA, IIC_CLK);

  Serial.begin(115200);
  while (!Serial);             // Leonardo: wait for serial monitor
  Serial.println("\nI2C Scanner");
}

void loop()
{
  byte error, address;
  int nDevices;

  Serial.println("Scanning...");

  nDevices = 0;
  for(address = 1; address < 127; address++ ) 
  {
    // The i2c_scanner uses the return value of
    // the Write.endTransmisstion to see if
    // a device did acknowledge to the address.
    Wire.beginTransmission(address);
    error = Wire.endTransmission();

    if (error == 0)
    {
      Serial.print("I2C device found at address 0x");
      if (address<16) 
        Serial.print("0");
      Serial.print(address,HEX);
      Serial.println("  !");

      nDevices++;
    }
    else if (error==4) 
    {
      Serial.print("Unknown error at address 0x");
      if (address<16) 
        Serial.print("0");
      Serial.println(address,HEX);
    }    
  }
  if (nDevices == 0)
    Serial.println("No I2C devices found\n");
  else
    Serial.println("done\n");

  delay(5000);           // wait 5 seconds for next scan
}