I2C Adress Scanner for Arduino

THIS PROJECT IS NOT MILLED AND PROGRSMMED YET

Find I2C address in serial monitor

Board

download: Eagle sch brd

BOM

Parts	Value	Qty
ATtiny412		1
capacitor	10uF	1
UPDI	angle 2 pinheader	1
FTDI	angle 6 pinheader	1
I2C	4 pin	1

PNG

Size: 32.4 x 22.5 mm

Sketch

ref.i2c_scanner
ref.megaTinyCore

#include <Wire.h>


void setup()
{
  Wire.begin();

 // megaTinyCore 2.0.0 or later 
 Serial.swap(0); // Default TX=0,RX=1
 //Serial.swap(1); // Alternat TX=2, RX=3

  Serial.begin(9600);
  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
}

In serial monitor

I2C Scanner
Scanning...
I2c device found at address 0x3C  !
done