The hardware equivalent of hello world is an LED flash, which is a great test to ensure that everything is working and that you have wired it correctly. To make it a little more interesting, I've suggested using a red, blue, and green (RGB) LED, but feel free to use separate LEDs if that is all you have available.
You will need the following equipment:
- 4 x DuPont female-to-male patch wires
- Mini breadboard (170 tie points) or a larger one
- RGB LED (common cathode)/3 standard LEDs (ideally red, green, and blue)
- Breadboard wire (solid core)
- 3 x 470 ohm resistors
Each of the preceding components shouldn't cost many dollars and can be reused for other projects afterwards. The breadboard is a particularly useful item that allows you to try out your own circuits without needing to solder them:
Diagrams of an RGB LED, a standard LED, and an RGB circuit
The following diagram shows the breadboard circuitry:
The wiring of an RGB LED/standard LEDs connected to the GPIO header