Here you can copy the master code or simply download it from the attachment down below. User will write in the serial monitor of the Master BlueOn or BlueOff to toggle the LED on the Slave. Now we will write a program which will enable a master to control an LED on the Slave Arduino.

Now let's start with the simple two Arduino wiring.

Each Arduino would have different internal operations and their actions would be determined by the master. One example would be to have one Arduino as a Master, two slave Arduinos each responsible for controlling two motors via Arduino bridge motor drivers, and a third Arduino connected with object avoidance ultrasonic sensors. In robotics for instance we prefer to have a single microcontroller controlling one set of sensors or actuators. At the end we will show how to have multiple Masters and multiple Slaves with four Arduinos.īefore all of that we would like to mentioned the reason why we would need so many Arduinos. That we show how to connect multiple Arduinos via I2C where one Arduino is the Master and has multiple Slaves. We will start with two Arduinos, one Master and one Slave, than we will add to this another Slave and adjust the Master code, than we will add yet another Slave to this and adjust the Master code again. Here we would like to show you how to connect multiple Arduinos through I2C communication.

Arduino wire library choose bus