Talking to hardware from your development board is when the real fun starts with a project. You can connect sensors, actuators, and more to make your project come alive with motion, sensation, sound, etc. However to communicate with other hardware typically requires knowledge of a serial protocol like I2C or SPI. These protocols are the common language that chips and add-on boards talk so they can be connected to a development board. The board knows how to ‘speak’ these protocols and control the connected hardware. This guide explores two very common serial protocols, I2C and SPI.