Using a Raspberry Pi Zero W and a blink(1) light for silent notifications

At my church, we often delay or “time slip” the preaching of the service in the room where the pastor isn’t physically present. To do this, we record the sermon video as it happens live, and then play it back out either a few seconds or few minutes later.

This has been a good workflow for us. Often though, in the delayed auditorium, it’s helpful for the worship leader to know when the server is ready to play back the delayed sermon video. We usually communicate this over the intercoms into the band in-ears, whenever there’s an appropriate break to do so, like when they aren’t actively singing, praying or talking. That works well, but sometimes it means we have to wait longer than we should to be able to let them know we are ready to play back the video.

So, I thought, if we had a simple cue light that we could use to let them know when we’re ready, I wouldn’t need to have my team wait to communicate. The band could just look at the light and know we are ready for them. It would also give that boost of confidence before they hear from us in the in-ears.

To create this system, I bought a Raspberry Pi Zero W and a blink(1) USB light. If you haven’t heard about the blink(1) light, I wrote about using it in this post. I bought the Pi Zero in a kit that came with a black case and power supply.

I had initially envisioned this light being located on stage but after talking to my team, they actually preferred that it be located on top of the camera back in the tech booth, so they could easily see it.

I’ve been learning Python recently, so I whipped up a simple Python web server that accepts HTTP requests to then light up the blink(1) light. For now, I’ve limited it to red and green. Red = problem like we aren’t sufficiently delayed, the server is not ready, etc, green = ready/good for playback anytime, and clear/no light = no status. I set up the Pi to start this web server when it boots up, so it’s very easy to set up.

We trigger the light using a Stream Deck Mini running Companion located at the video server. The operator has three buttons, and each one sends an HTTP request to the Pi Zero to trigger the light.

I also have a command set for each button action on the stream deck to update a button on another stream deck in the other control room, so each director knows the status of the video server. This doesn’t replace our intercom communication, but it certainly augments it!

Overall, we’re very happy with this notification system! All in, it cost us about $55 for the Pi Zero kit and the blink(1) light, and of course, the code was free. 🙂 It’s available on Github if you need it! That’s where I will provide updates as I add more features to this.