Since there is more than one slave in the bus, the master has to refer to each slave using a different address. Serial Data (SDA): Sends the data to and from between the Master and slave.Īt any given time only the master will be able to initiate the communication. Serial Clock (SCL): Shares the clock signal generated by the master with the slave The complete communication takes place through these two wires namely, Serial Clock (SCL) and Serial Data (SDA). The advantage of I2C communication is that more than one slave can be connected to a Master. Communication should and will always occur between two a Master and a Slave. Here one device is called a master and the other device is called as slave. As said earlier it has two wires, these two wires will be connected across two devices. I2C communication was first introduced by Phillips. It has only two wires to share information out of which one is used for the cock signal and the other is used for sending and receiving data. I2C is a synchronous communication protocol meaning, both the devices that are sharing the information must share a common clock signal. It is normally denoted as I2C or I squared C or even as 2-wire interface protocol (TWI) at some places but it all means the same. The term IIC stands for “ Inter Integrated Circuits”.

So let’s start with the introduction about I2C communication.

Here one Arduino will act as Master and another one will act as Slave. Values will be displayed on the 16x2 LCD connected to each of the Arduino. In this Arduino I2C tutorial we will use I2C communication between two arduino boards and send (0 to 127) values to each other by using potentiometer. I2C communication is generally used to communicate with Gyroscope, accelerometer, barometric pressure sensors, LED displays etc. So there are more than one microcontroller in a project that need to be masters then I2C is used. Comparing I2C with SPI, I2C has only two wires while SPI uses four and I2C can have Multiple Master and Slave, while SPI can have only one master and multiple slaves. Today we will learn about another Serial Communication Protocol: I2C (Inter Integrated Circuits). In our previous tutorial learned about SPI communication in Arduino.

Wire arduino library