On the Top window in the text box enter the letter x … not the capital X … the LED on the Arduino UNO(Adafruit 328) goes ON.

On the Arduino Mega UART1 program window of the Arduino IDE, make sure your COM is selected to the Arduino Mega before opening the Serial Console, Open the Serial Console set to 9600 baud COM Speed.

Connect Arduino Mega to the Computer from the USB cable.

Connect Arduino UNO to a Stable/Reliable power source.

Connect the ground pin on the Mega to the ground pin on the Arduino UNO(Adafruit 328).

Connect one end of a wire to Mega's pin18 TX1 and the other end to Arduino UNO's(Adafruit 328) pin0 RX.

Connect one end of a wire to Mega's pin19 RX1 and the other end to Arduino UNO's(Adafruit 328) pin1 TX.

Upload the the codes to Arduino Mega and Arduino UNO(Adafruit 328).MEGA to Adafruit 328(Arduino UNO) UART to UART connection. The Leonardo will use the SoftwareSerial example but if using the UART same will apply as the Arduino UNO's. This will not allow the Arduino UNO(Adafruit Metro 328) to communicate with the outside world AKA your computer. Please follow this step because your Arduinos use the 'DEFAULT' SerialPort to upload your code from the Computer, once you make the physical wire connections the 'Default' SerialPort will be used on the Arduino UNO (Adafruit Metro 328) to communicate with the Arduino Mega 2560 R3's SerialPort #1 which is pin19 RX1 and pin18 TX1 on the Mega. The connections will be UART to UART, SoftwareSerial to SoftwareSerial, UART to SoftwareSerial, and ALL 3 connected together!! :)īefore you make the physical wire connections. If you ever wonder how to use the other Serial ports on the Arduino Mega 2560 R3, but don't know where to start? This short tutorial we'll go over the basics, we'll connect to an Adafruit Metro 328 = its an Arduino compatible works just like an Arduino UNO R3, and we will connect to an Arduino Leonardo clone. This tutorial we are covering Serial Port Basics on the Arduino Mega 2560 R3.

Arduino mega 2560 driver for mac