About the Author
Tanya was formerly in schools, teaching maths, and physics, & shouting loudly at paperwork. Pirate crew member since 2016 - making learning materials for schools, running workshops, & doing talks.
@tanurai

Traffic Lights

You can make a set of traffic lights for use with your micro:bit using the following materials:

Piece of cardboard
Silver foil - Glue stick
3 x LEDs (red, orange, green)
Sellotape

Step 1:

First, cut a piece of card about the size of a playing card. Cut a strip of tinfoil the length of the card. Bend the legs outwards on the LEDs and give them a bit of a bend.

Card, foil and LEDs prepared for the next step

Step 2:

Glue the left third of the card as in the diagram, and smooth the foil down. Bend the foil around the back of the card and glue that down too. Take some more foil and glue three patches around the right-hand third of the card. Make sure they don’t touch. Make sure they go around the back too.

Front and back of the card with foil glued on

Step 3:

Now we’re going to attach the LEDs. It is very important that the flat side of the LED (negative) is on the strip side, and the rounded side (positive) is on the patch side. Tape the LEDs down with one leg on the long strip of foil, and the other leg on a single patch, as shown in the diagram.

Tape down the LEDs, taking care to put them the right way around

Step 4:

Finally, wire up to your micro:bit as in the diagram:

Use crocodile clips to attach your board to the micro:bit

Code

I used the following code to cycle through the pattern like a real set of lights does. You might want to change the timings or try to make different light patterns like running lights or a Knight Rider style Larson scanner.