#include <Wire.h>
void setup() {
  Wire.begin();
  Serial1.begin(9600);
  while (!Serial1); // Leonardo: wait for serial monitor
  Serial1.println("\nI2C Scanner");
}
void loop() {
  byte error, address;
  int nDevices;
  Serial1.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) {
      Serial1.print("I2C device found at address 0x");
      if (address < 16)
        Serial1.print("0");
      Serial1.print(address, HEX);
      Serial1.println(" !");
      nDevices++;
    } else if (error == 4) {
      Serial1.print("Unknown error at address 0x");
      if (address < 16) Serial1.print("0");
      Serial1.println(address, HEX);
    }
  }
  if (nDevices == 0)
    Serial1.println("No I2C devices found\n");
  else
    Serial1.println("done\n");
  delay(5000); // wait 5 seconds for next scan
}