Entangled Notification Lights

With the current spate of COVID-mandated teleworking, I have discovered that my significant other can be quite... vocal while teleconferencing. We are both often wearing noise-cancelling headphones and in zoom calls, so grabbing the others' attention can be a challenge.

We came up with this little solution as a weekend project. We each have one of these devices in our line of sight while working, and if we touch one of the colored buttons on our unit it makes the lights of the other one flash. This way we can communicate short messages unobtrusively even if the other person is on a zoom call. For us, blue means "hi!", green is "check the chat" and red is "you're being too loud!".

You can see them in action here:

The touch sensors are 3 TTP223 Capacitive touch sensors, the LEDs are a 4-LED strip of WS2801 LEDs and the brain is an ESP8266 NodeMCU v2. I don't have a multi-material printer, so I printed the buttons in different colors and glued them to the holes of the top part.

My units are programmed with ESPHome and communicate through a Home Assistant instance, but a similar thing can be done with plain Arduino and direct communication between the two.