case 04 trimpot
Introduction
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.
Products Link
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
Trimpot
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.
Software
Step 1
Click makecode https://makecode.microbit.org/#。
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
Program link：https://makecode.microbit.org/_VewWgwe8HVT1
You also could directly download program by visiting website as below:
Result
Rotate the trimpot, the height of the bar graph will change.
think
Is the trimpot could be a fixed resistance？