#include <Wire.h>

#define SDA_0 21
#define SCL_0 22
#define I2C_Freq 100000

TwoWire I2C_0 = TwoWire(0);

void setup() {
  Serial.begin(115200);
  I2C_0.begin(SDA_0, SCL_0, I2C_Freq);
}

void loop() {
  Serial.println("Scanning...");
  int nDevices = 0;
  for (byte address = 1; address < 127; address++) {
    I2C_0.beginTransmission(address);
    if (I2C_0.endTransmission() == 0) {
      Serial.print("I2C device found at address 0x");
      Serial.println(address, HEX);
      nDevices++;
    }
  }
  if (nDevices == 0) Serial.println("No I2C devices found");
  Serial.println("Done\n");
  delay(5000);
}