Vintage Remote Control Gets Bluetooth Upgrade

This swanky Magnavox remote is old enough to predate the use of infrared, and actually relies on ultrasound to communicate with the television. It’s a neat conversation starter, but not terribly useful today. Which is why [Chad Lawson] decided to gut the original electronics and replace it with a Adafruit Feather 32u4 Bluefruit LE that can actually talk to modern devices.

We know, we know. Some in the audience will  probably take offense to such a cool gadget being unceremoniously torn apart, but to be fair, [Chad] does say he has a second one that will remain in its original state. Plus a quick check on eBay shows these old remotes don’t seem to be particularly rare or valuable. In fact, after some browsing through the recently concluded auctions, we’re fairly sure he paid $27 USD for both of these remotes.

Anyway, [Chad] found that a piece of perfboard in his collection just happened to be nearly the same size as the PCB from the remote, which made the rest of the conversion pretty straightforward. He simply had to mount tactile switches on one side of the perfboard so the remote’s original buttons would hit them when pressed, and then wire those to the Adafruit on the other side. We know there’s a 3.7 V 500 mAh pouch battery in there someplace as well, though it’s not immediately clear where he hid it in the images.

The code [Chad] came up with tells the Adafruit to mimic a Bluetooth Human Interface Device (HID) and send standard key codes to whatever device pairs with it. That makes it easy to use as a media remote on the computer, for example. We’ve seen something similar done with the ESP32, if you’ve already got one in the parts bin and are looking to revamp a remote control of your own.

At the end of the write-up, [Chad] mentions he may try developing an ultrasonic receiver that can pick up the signals from the unmodified remote control. That would be a nice way to bring this whole thing full circle, and should appease even the most hardcore vintage remote control aficionados.

20 thoughts on “Vintage Remote Control Gets Bluetooth Upgrade

  1. Electronics? Heck, that original Magnavox remote is positively modern compared with the first TV remote I ever laid hands on! It was a Zenith. Four buttons, each of which cocked and released a kind of hammer which struck the equivalent of a tuning fork. Look Ma – no batteries!

  2. A cooler project would have been to put that fancy microcontroller to some real use and have it do digital signal processing on a microphone signal to recover the utlrasound signals from the remote… no need to damage the original, just make an ultrasound-to-bluetooth adapter.

    1. That is the current version which I submitted to Hackaday’s “Reinvented Retro Contest” recently. The contest was the kick in the pants I needed to get it going.

      It’s far from finished, but I started with some frequency detection code and the plan is to have a listener sit on my desk and convert those frequencies to keyboard presses.

      I was surprised (but super pleased) that Hackaday did a write-up of V1, but it is the one that’s actually finished, so it makes sense.

    1. That’s an interesting idea. I’d assume you’ed used the same training methods as standard click training, just with the remote. (Assuming the dog can hear in that range, which it probably can.)

    2. When I was playing around with the unmodified remote, I did try that. We have three Beagles and none of them seemed to notice, let alone care.

      However, when I aimed it at my head my hearing aids picked it up, but only when it was really close and at the right angle to the microphones.

  3. No dead batteries ever, this could be in use today for many purposes, maybe not TV though with DSP we could do more tones and combos but why not for air conditioners.
    I would prefer this if I were not using a 2.4ghz airmouse remote to control a Kodi box connected to a dumb flatscreen TV.
    Sometimes eliminating the electronics on a mobile device is the answer.

  4. The Zenith Space Command is the ultrasonic remote that struck tuned metal rods with hammers. Magnavox countered with the Astro-Sonic (later Phantom) which used two or more ultrasonic whistles. Looking online I’ve seen versions with two and three buttons.

    Hold it up to an ear, press a button and you can hear a quiet *chuff*.

    As yet nobody has bothered to do a teardown of an Astro-Sonic or Phantom remote and post the pictures so we can all see how they work. People sell and buy these things but why won’t anyone take one apart???

    The purely mechanical Magnavox remotes were superseded by the electronic versions like in this article. I assume because packing more than 3 (or perhaps 4) of the whistle mechanisms into a remote would have made it too big.

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