Skip to main content

Case 26: The Volume Indicator


This is a sound warning device. As we all know, noise pollution seriously affects our lives. If we are exposed to a certain decibel noise for a long time, our physical and mental state will also be harmed. Thus, we can make a noise detection device. Different decibel values light up different colors of lights to remind people to keep quiet.

Quick Start

Materials Required

Nezha expansion board × 1

micro:bit V2 × 1

Rainbow LED ring × 1

Bricks × n

Tips: You may need to purchase Nezha Inventor's Kit and Purchase Interactive coding accessories pack here. if you want all the above components.

Connection Diagram

Inset the micro:bit, and connect the rainbow LED ring to IIC port on Nezha expansion board.

Assembly Video

Video link:

Assembly Steps

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



You may download it directly below:


After powering on, the rainbow LED ring lights up in different colors reflecting with the ambient sound level.