On-Air Sign

Background

The whole idea came to me during the early covid-19 days, when my whole family (2 parents, 3 kids) was forced to remain at home, and both parents desperately attempting to get some work done from home.

After being interrupted time after time during voice and video calls I thought to myself how handy it would have been if I had an electrical sign that can display my current status, whether I'm in a call, my video cam is active and so on (if you ever tried to work from your bedroom and had to signal your partner that its probably not a good time for changing shirt while standing behind you, you know what I'm talking about)

Well, I couldn't find any, neither I had any real Arduino experience back then, but I do have quite some C and embedded programming experience plus some knowledge in electronics.

So by the time we were having the second Covid lockdown, I had the parts available plus the extra time as there wasn't much else to do.

How does it work

The Arduino part is pretty simple, I used an Arduino nano cheap clone wired to a LED matrix. The Arduino software is capable of displaying two elements, representing the microphone and the speakers and adding an animation overlay to signal when they are in use. It is controlled from a host PC by a USB cable, using a made-up text based protocol that allow the host PC to detect the connection status and control the display status.

The host part is a simple WinForms application (written in c#) that polls the host PC microphone and speakers status and update the LED display accordingly.

Required hardware and pricing

• Arduino Nano clone - ~7$

• Max7219 8x32 LED matrix - ~6$

• A breadboard (optional) and some male-to-female wires

More information

I uploaded an hebrew-speaking video which explains the use of the "On Air" sign.