# Case 30: Adjustable lights

## Introduction

This is an adjustable LED light. We can adjust the brightness of the light through the potentiometer, so that the light is at our most comfortable brightness.

![](./images/case_30_01.png)

## Quick Start 


### Materials Required

Nezha expansion board × 1

micro:bit V2 × 1

Analog Rotation Potentiometer  × 1

Rainbow LED ring  × 1

Bricks × n

***Tips: You may need to purchase [Nezha Inventor's Kit](https://shop.elecfreaks.com/products/elecfreaks-micro-bit-nezha-48-in-1-inventors-kit-without-micro-bit-board?_pos=2&_sid=ed1b6fbd2&_ss=r) and [Purchase Interactive coding accessories pack here.](https://shop.elecfreaks.com/products/elecfreaks-interactive-coding-accessories-pack?_pos=1&_sid=c75dad35f&_ss=r) if you want all the above components.***


### Connection Diagram 

Inset the micro:bit, connect the rainbow led ring to J1 port and the trimpot to J2 port on Nezha expansion board. 


![](./images/case_30_03.png)



### Assembly Video


Video link: [https://youtu.be/IDo75YvbOB8](https://youtu.be/IDo75YvbOB8)

<iframe width="560" height="315" src="https://www.youtube.com/embed/IDo75YvbOB8" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>

### Assembly Steps

![](./images/case_step_30_01.png)

![](./images/case_step_30_02.png)

![](./images/case_step_30_03.png)

![](./images/case_step_30_04.png)

![](./images/case_step_30_05.png)





## MakeCode Programming 




### Step 1



Click "Advanced" in the MakeCode drawer to see more choices. 

![](./images/case_01_10.png)




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

![](./images/case_03_09.png)

***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


![](./images/case_30_10.png)



### Reference

Link: [https://makecode.microbit.org/_9zD1etLWh36q](https://makecode.microbit.org/_9zD1etLWh36q)

You may download it directly below: 

<div style="position:relative;height:0;padding-bottom:70%;overflow:hidden;"><iframe style="position:absolute;top:0;left:0;width:100%;height:100%;" src="https://makecode.microbit.org/#pub:_9zD1etLWh36q" frameborder="0" sandbox="allow-popups allow-forms allow-scripts allow-same-origin"></iframe></div>  


### Result 
After powering on, the luminance level is able to be adjusted by the trimpot.

![](./images/case-gif-30.gif)