Save the World with Code: 20 Fun Projects for All Ages Using Raspberry Pi, micro:bit, and Circuit Playground Express

MISSION 11

Number Lock for Your Devices

The problem with the cookie jar alarm is that sometimes we need cookies. And we don’t want our cookie enjoyment ruined by an alarm constantly going off! We also need to get into our room without the door alarm going off.

Let’s create a number lock for the cookie jar for the micro:bit and Circuit Playground Express and a number lock for the door for the Raspberry Pi. This will be more secure than the sword lock, because you have to enter a number to unlock it. The alarm will give you 10 seconds to enter the correct code before it goes off.

We can scroll through numbers using the A button, and submit a guess using the B button on the micro:bit and the Circuit Playground Express. On the Raspberry Pi, we’re ...