37. Case 36: Color Recognition Password Door

37.1. Introduction

To make a color recognition password door.


37.2. Quick Start

Materials Required

Nezha expansion board × 1

micro:bit V2 × 1

color sensor × 1

Servo × 1

Crash sensor × 1

Bricks × n

Tips:Purchase Interactive coding accessories pack here.

Bricks Required


Connection Diagram

  • Inset the micro:bit, connect the color sensor to IIC port, the 360 degrees servo to S1 and the crash sensor to J1 port on Nezha expansion board.


Bricks Build-up

  • Build a device as the pictures indicate:




Video link: https://youtu.be/WiSpnc5fPbA

37.3. MakeCode Programming

Step 1

Click “Advanced” in the MakeCode drawer to see more choices.


We need to add a package for programming. Click “Extensions” in the bottom of the drawer and search with “nezha” to download it.


Note: If you met a tip indicating the codebase might be deleted due to incompatibility, you may continue as the tips say or create a new project in the menu.

Step 2

Programme as the pictures indicate



Link: https://makecode.microbit.org/_3xJgWP2ig48r

You may download it directly below:



  • Sending the passwords via the colors, press the crash sensor to confirm after you choose the colors ready, the door would open if the two passwords are correct or the micro:bit displays “x” and the program reruns.