---
title: Input from a Potentiometer
---

# #09. Input from a Potentiometer

<div class="ui segment note">
<span class="ui ribbon label">Note</span>
This is a web-version of a tutorial chapter embedded right into the XOD IDE.
To get a better learning experience we recommend to install the
<a href="/downloads/">desktop IDE</a> or start the
<a href="/ide/">browser-based IDE</a>, and you’ll see the same tutorial there.
</div>

Another ubiquitous source of values is a potentiometer (or simply “pot” for
short). It is very handy to adjust some parameters smoothly.

There is a special node `pot` to read values from a potentiometer. You will
find it in the `xod/common-hardware` library.

![Patch](./patch.png)

## Test circuit

![Circuit](./circuit.fz.png)

[↓ Download as a Fritzing project](./circuit.fzz)

## How-to

1. Add the `pot` node to your patch.
2. Set the `PORT` pin value on the `pot` node to 0 if you have connected
   the potentiometer to Arduino port A0 as shown above.
3. Link the `pot` node `VAL` pin to input pins of nodes to control.

![Screencast](./screencast.gif)

In our example, if you turn the potentiometer knob, it will affect the
brightness of the LEDs. Depending on the angle of the knob, the `pot` node
returns a value from 0.0 to 1.0 to the `VAL` pin, and that value is transferred
to the `LUM` pins of both LED nodes.

[Next lesson →](../10-math/)