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case 04 trimpot


The trimpot is a common pressure regulation component. In this case, we are going to read output voltage of the trimpot and show the voltage with a bar graph in 5*5 LED allay of micro:bit.

ELECFREAKS Experiment Box Kit

Hardware Connect

Connect circuit as above picture and put 2 AAA batteries to the batteries pack.

Principles of Circuits

The GND of slot on micro:bit is into innards of batteries' GND to generate current loop.

Introduction of Components


The trimpot is a pressure regulation component which included a resistance and a slide system. The resistance measured varies based on the movement of a knob or slider between the middle terminal and outer terminals. There is a 10KΩ trimpot on the experiment box. When it turns left, it will be 0Ω; when it turns right, it will be 10KΩ.


Step 1

Click makecode

Click on "New Project" and set a new Project.

Step 2

Snap plot bar graph into the forever to show a bar graph.(A bar graph is a kind of table which can show number by diffrent lengths.)

"analog read pin" is to read a signal of a pin.(0~1023)


Program link:

You also could directly download program by visiting website as below:


Rotate the trimpot, the height of the bar graph will change.


Is the trimpot could be a fixed resistance?


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