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JEJunior Engineer LabPico W + micro:bit course
01 25 minutes

First external light

Build a real circuit on the breadboard and light an LED you can hold

First external light project
Illustration of the finished idea. Build from the diagram and connection table, not the photo.

Mission goal: Wire GP16 through a 1 kΩ resistor into a red LED and back to ground, then switch it on for ten seconds from code.

Section 1

Understand

New ideas

  • How breadboard rows connect to each other
  • GPIO numbers versus physical pin numbers
  • Why a resistor is not optional
  • LED polarity: long leg versus flat side
  • 1Electricity flows in a loop: pin → resistor → LED → ground.
  • 2The LED's long leg faces the resistor. The 1 kΩ resistor is never skipped.
  • 3Pin(16) means GPIO16, which is physical pin 21.

Safety first

  • Build and change wiring with the USB cable unplugged. Plug in only when the circuit is finished and checked.
  • Never connect a GPIO pin straight to ground with no resistor and no LED. That is a short circuit.
  • Check the LED's long leg points away from ground before you power up.