I2C vs SPI vs UART: Wiring, Speed, and How to Choose

A side-by-side comparison of the three serial buses every microcontroller project runs into — I2C, SPI and UART — across four axes: number of signal lines, speed, how many devices you can hang off them, and wiring distance. Includes a decision flow and what to look for on a scope.

July 20, 2026 · 20 min · 

Arduino RGB LED PWM Control: 8 Colors to 16.7 Million

A complete guide to controlling full-color RGB LEDs with Arduino PWM. From basic 8-color digital output to smooth 16.7 million color gradients using three-phase sine waves — with circuit diagrams and ready-to-use sample code.

July 13, 2020 · Updated: July 20, 2026 · 8 min · 

Ohm's Law LED Resistor Calculation for Arduino Beginners

Learn how to safely light up an LED using Ohm’s Law. Calculate the correct resistor value, wire a breadboard circuit, and avoid common mistakes — a complete beginner’s guide.

June 15, 2020 · Updated: August 18, 2026 · 4 min ·