If any company has benefited from the coronavirus pandemic, it has been Zoom Video Communications. They make teleconferencing software that has been incredibly popular for people working or studying from home while quarantined. Yes, their stock has taken a big hit since Pfizer announced a vaccine that seems very promising, but people will likely still be using Zoom and other video conferencing software for quite a bit longer. As a matter of etiquette, most people agree that you should be muting your mic as much as possible to avoid obtrusive sound. That’s why Samuel (AKA TheStaticTurtle) built a device that automatically mutes his mic whenever his bedroom door is open.
Samuel is a university student in France, and a lockdown has forced him to study from home where he lives with his parents. Occasionally one of them will barge into his room, as parents are wont to do. Nobody wants their classmates to hear their parents ask them if they want the crust cut off their sandwich, and so Samuel came up with this device. He mounted a sensor, similar to the kind used for security systems, to the door frame. Wires run from that sensor to the device connected to Samuel’s computer. Whenever it detects that the door is open, audio software running on the computer automatically mutes the microphone.
This device is controlled by a Microchip ATtiny85 microcontroller, which Samuel setup to work similarly to the Digispark Digistump board. It’s running the Digispark bootloader, which lets the device appear as a standard USB HID keyboard when it is plugged into a computer. It monitors the door with a simple magnetic sensor on the doorframe, with a permanent magnet attached to the door itself. When the door is opened, the ATtiny85 sends a CTRL + ALT + F2 key combo to the computer. When closed, it sends CTRL + ALT + F3. These correspond to mute and unmute, respectively.
Samuel is actually using two computers, with Synergy software to make them work like he’s using a KVM (Keyboard Video Mouse) switch. To manage audio, he’s using VB-Audio’s VoiceMeeter Potato software. Those keyboard shortcuts are intercepted by this software. Samuel even setup an indicator icon that is overlaid on the monitor whenever the microphone is muted, giving him the peace of mind that classmates won’t hear whatever mom or dad are saying after they open the bedroom door.