All labs

Electronics bench

Build real circuits from a supply, a resistor and an LED — then measure them, break them, and fix them. Ends where a microcontroller begins.

Briefing

You are at a workbench with a battery, some resistors and a handful of LEDs. Nothing is wired yet. Over eight boards you light your first LED, learn why it needs a resistor, measure one with Ohm's law, and finish where a microcontroller pin takes over.

You'll learn to

  • Wire a working LED circuit and say why the resistor is there
  • Use Ohm's law to pick a resistor from a voltage and a current
  • Tell series from parallel, and find why a circuit isn't working
  • Read a switch, and then a microcontroller pin, as a gap you open and close
0 of 8 steps done0%
Start: Close the circuit
Before you build a circuitOptional warm-upVoltage, current, resistance, and why an LED always needs a resistor. Ten minutes.

  1. Close the circuit

    Up next

    Why nothing happens until the loop is complete

  2. Which way round

    An LED only works one way, and nothing warns you

  3. Pick the resistor

    Enough to be bright, little enough to survive

  4. Ohm's law

    The mystery resistor

  5. Two at once

    Side by side, not end to end

  6. Why isn't it working

    Nothing is unplugged. It still does not light.

  7. A switch is a gap

    Controlled on purpose, this time

  8. A pin is a switch

    The one the program presses