Vintage Aircraft Controls Turned USB Button Box

The Gables Engineering G-2789 audio selector panels aren’t good for much outside of the aircraft they were installed in, that is, until [MelkorsGreatestHits] replaced most of the internals with a Teensy 3.2. Now they are multi-functional USB input devices for…well, whatever it is you’d do with a bunch of toggle switches and momentary push buttons hanging off your computer.

Tracing wires from the panel switches.

With the Teensy going its best impression of a USB game controller, the host operating system has access to seven momentary buttons, twelve toggles, and one rotary axis for the volume knob.

Right now [MelkorsGreatestHits] says the code is set up so the computer sees a button press on each state change; in other words, the button assigned to the toggle switch will get “pressed” once when it goes up and again when it’s flicked back down. But of course that could be modified depending on what sort of software you wanted to interface the device with.

As we’ve seen with other pieces of vintage aircraft instrumentation, lighting on the G-2789 was provided by a series of incandescent bulbs that shine through the opaque front panel material. [MelkorsGreatestHits] replaced those lamps with white LEDs, but unfortunately the resulting light was a bit too harsh. As a quick fix, the LEDs received a few coats of yellow and orange paint until the light was more of an amber color. Using RGB LEDs would have been a nice touch, but you work with what you’ve got.

This isn’t the first time that [MelkorsGreatestHits] has turned an old aircraft cockpit module into a USB input device, and we’re certainly interested in seeing what the next project will look like. Though we’re perhaps more interested in finding out where all all these old school airplane parts are coming from…

4 thoughts on “Vintage Aircraft Controls Turned USB Button Box

  1. OMG, such a blast from my past. In the 80’s I worked for a sub-contractor that wired many of those boxes for Gables Engineering. GE had such a great crew to work with :-D

    1. I’ve been trying to identify some of the bits inside the box, and discovered that GE are still in operation, and have offices and service centers around the world. They even make modern versions of this panel.

      I identified 12 relays, with changeover contacts. The 4 silver cylinders could be either RF relays or transformers. The 4 circuit boards do look like some sort of PSU, but the photo is not sharp enough to say anything more. However I am suspicious of the large “gold” mounting screws. I remember that colour being a beryllium oxide with high heat conductivity that was used for small heat-sinks. It was eventually discovered to be very toxic. When I was at thee BBC in the 70s, I was given the job of taking all the beryllium components out of all the video amplifiers in one of the production studios! I had to use a fume hood.

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