Reff

if you’re getting into embedded systems, learn these protocols in this order: 1. i2c two wires. many devices. perfect for sensors, displays, rtc modules, eeproms master/slave architecture simple to wire, easy to prototype this is where most beginners should start. 2. spi much faster than i2c separate lines for data in, data out, clock, and chip select ideal for displays, sd cards, high-speed sensors more wires, much higher performance when speed matters, spi wins. 3. uart point-to-point communication tx + rx no clock line used for debugging, gps, bluetooth modules, microcontroller communication if you’ve ever opened a serial monitor, you’ve already used uart. learn them in this order: i2c → understand device communication spi → understand high-speed peripherals uart → understand serial communication and debugging these three protocols are everywhere. master them once, and you’ll find them in almost every embedded system you build.