Use Your New Raspberry Pi Pico to Build a Hardware Mute Button for Microsoft Teams

If your life has been anything like the rest of ours over the past year, you’ve probably found yourself doing a lot of video conferencing. You’ve probably also discovered that those conferences require some unique etiquette. For example, you should absolutely check the shelves behind you for embarrassing items before joining the conference and should be make sure that you’re wearing pants before standing up. But the most important etiquette to follow is muting your microphone when you’re not speaking. If you’re lucky enough to own a Raspberry Pi Pico, Tommaso Tani has a guide on how you can use it to build a hardware mute button for Microsoft Teams.

The new Raspberry Pi Pico is a very capable development board thanks to its powerful RP2040 microcontroller. It is also quite affordable at just $4 and offers USB HID functionality, which makes it ideal for a project like this. That is because all the popular video conferencing programs let you control important functions, like muting the microphone, with keyboard shortcuts. In Microsoft Teams, CTRL + shift + M mutes the microphone and CTRL + shift + B ends the current video call (in Windows). If you’re using other software or a different operating system, the keyboard shortcuts may be different. Since the Raspberry Pi Pico can emulate a USB HID keyboard, it can easily send those keyboard shortcuts to your computer.

The only hardware you will need to build your own Mute-o-Matic V2 is the Raspberry Pi Pico development board, two normally-open panel mount push buttons, an LED, a slide switch, and an approximately 220 ohm resistor. The slide switch is used to actually turn on the Pico and the LED (with resistor) lights up to indicate that the Pico is on. The two push buttons are used to tell the Pico to send either the mute keyboard shortcut or the end call shortcut. The electronic components can be housed within a simple 3D-printed enclosure.

All of the code to make this work is provided and can be easily modified for use with Zoom or any other software. The Mute-o-Matic V2 is “dumb,” which means that it doesn’t actually know what is happening on your computer. That can be an issue when sending shortcuts if the video call window doesn’t have focus. To get around that, you can add a couple of additional shortcuts to give the video call window focus before sending the mute or end call shortcuts. Now you can quickly and easily mute your video calls, or end the call before standing up without pants.