Embedded protocols

Embedded protocols are the agreed ways chips and devices talk to each other over a few wires. UART is the simple one: two devices, one wire each way, both agreeing on the speed in advance. SPI is fast and uses a shared clock, but needs an extra select wire for each device. I2C gets many devices onto just two wires by giving each an address, at the cost of speed. CAN is a robust shared bus built for cars and industrial machines, where messages carry priorities and survive electrical noise. On top of these, higher-level formats like MAVLink for drones, or ROS for robotics, define what the messages actually mean.