led
4 pages across tutorials, modules, pinouts and guides.
10-Segment LED Bar Graph Display
Ten independent LEDs in one 20-pin package, with a resistor board that puts 220 Ω in front of each. Which way round it goes, why LOW lights a segment, and what ten of them at once costs an Arduino.
RGB LED
A red, a green and a blue LED in one 5 mm package, each with its own 1 kΩ resistor and its own pin, joined at a common cathode. Three PWM pins mix any colour, and the handbook works out why three equal numbers are not white.
Traffic Light
Red, yellow and green LEDs, each with its own 1 kΩ resistor and its own pin, sharing one GND: three digital outputs, and the first sketch that has to remember what it is doing.
XL LED
A 10 mm blue LED with its 150 Ω resistor already fitted, driven by one pin: the first output most people ever drive, and the light every later lesson uses to show that something happened.