Arduino sketch

/* Heltec Automation I2C scanner example (also it's a basic example how to use I2C1)
 *
 * ESP32 have two I2C (I2C0 and I2C1) bus
 *
 * OLED is connected to I2C0, so if scan with Wire (I2C0), the return address should be 0x3C.
 *
 * If you need scan other device address in I2C1...
 *      - Comment all Wire.***() codes;
 *      - Uncomment all Wire1.***() codes;
 *
 * I2C scan example and I2C0
 *
 * HelTec AutoMation, Chengdu, China
 * 成都惠利特自动化科技有限公司
 * www.heltec.org
 *
 * this project also realess in GitHub:
 * https://github.com/HelTecAutomation/Heltec_ESP32
 * */

#include "Arduino.h"
#include "heltec.h"

#if defined( WIRELESS_STICK_LITE )
    #include <Wire.h>
    #include "oled/SSD1306Wire.h"

    static const uint8_t SCL_OLED = 15;
    static const uint8_t SDA_OLED = 4;
#endif

void setup()
{
    Heltec.begin(true, false, true);
    Wire.begin(SDA_OLED, SCL_OLED); //Scan OLED's I2C address via I2C0
    //Wire1.begin(SDA, SCL);        //If there have other device on I2C1, scan the device address via I2C1
}

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

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

    nDevices = 0;
    for(address = 1; address < 127; address++ )
    {
        Wire.beginTransmission(address);
        error = Wire.endTransmission();

//      Wire1.beginTransmission(address);
//      error = Wire1.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);
}