Prototyping with the I2C protocol
In the previous section, sensors or actuators were directly communicating with Arduino via digital, analog, or PWM pins. These methods are utilized by a large number of basic, low-level sensors and you will be widely using them in your future Arduino projects. Beside these methods, there is a wide variety of popular sensors that are based on integrated circuit (IC), which require different ways of communication. These IC-based advanced sensors utilize I2C- or SPI bus-based methods to communicate with the microcontroller. As we are going to use I2C-based sensors in the upcoming projects, the section will only cover the I2C protocol and practical example to understand the protocol in a better way. Once you understand the fundamentals of the I2C protocol, you can learn the SPI protocol very quickly.
Note
You can learn more about SPI protocol and the supported Arduino SPI library from the following links:
