Raspberry Pi Pico Onboard LED Blink (GP25 Built-in LED)
The opening project of the Raspberry Pi Pico series! We blink the onboard LED (green LED connected to GP25) to verify the board works — a classic "Hello World" first experiment. NO external components, just Pico and USB cable. Code is written in **MicroPython** (the official language backed by Raspberry Pi Foundation). Learn `machine.Pin` class, `Pin.OUT` mode, `led.on()/off()` methods, and `time.sleep()` in Thonny IDE. Follow every toggle live in the Serial (REPL) output. Also perfect to verify
