Many sensors provide a voltage level which informs the Raspberry Pi or a microcontroller such as the Arduino about their change of state. Now recall that the Raspberry Pi's GPIO pins are designed for use with 3.3V inputs and outputs. Some sensors operate on 5V, so feeding its output directly to the Raspberry Pi's GPIO pins runs the risk of damaging either the sensor or the Raspberry Pi. Imagine not knowing about this and wiring it up erroneously, you'd hope to see spectacular blow-ups and magic smoke! However, we usually see nothing, no fun at all - it just eventually stops working. Which can be frustrating when it comes to troubleshooting. Other times though, you need a voltage adjustment in both directions so that devices can communicate in both directions across the same wire.
In this guide, you'll learn about logic-level shifters, specifically the bi-directional logic level shifter.
Complete this guide to set up a Raspberry Pi with a Little Bird Uno R3, so they can communicate bi-directionally via the I2C protocol!