Dog-Harnessing The Power Of Walkie Talkies

[javier.borquez] likes to take his dog to the hang out at the dog park around dusk. But once the sun goes down and [Rusio]’s off the leash, running amok with the other dogs, it’s almost impossible to keep track of him.

Sure, there are probably glow-in-the-dark or lighted collars out there, but if you go commercial, chances are good that someone else’s dog will be wearing the same thing. Besides, what’s the fun in buying something that you can do a better job making yourself? With this dog distance indicator harness, you don’t even have to program anything. Instead, it uses a cheap pair of modified walkie talkies to show green LEDs on the harness while the dog is in range, and red when it isn’t.

Although [javier]’s pupper is the best pupper yes he is, [Rusio] can’t be expected to hold down the button and bark his location. His walkie talkie uses a 555-based frequency generator and a glued-down button to speak at 1 kHz.

Over in [javier]’s walkie, there’s a resistor in place of the speaker to keep the talkie parts working. There’s also a half-wave bridge rectifier that charges a capacitor when [Rusio] is within range, and a resistor that drains it when he’s outside the 6-8 meter range. The rectifier’s output goes to a second 555 set up as a Schmitt trigger, which tells a transistor to turn the red LEDs on instead.

If you got stuck on the idea of hearing your dog talk to you over distances, here’s a Bluetooth Babelfish collar.

11 thoughts on “Dog-Harnessing The Power Of Walkie Talkies

  1. Instead of spending time making stuff to find your dog. You should invest that time into teaching your dog to listen to you when you say come. Or just buy a shocker collar, and when you hit the button listen for the “Yipe”.

    1. Ugh no a shock collar is terrible advice, that’s how you end up with aggressive, anxious unpredictable dogs. Never recommend them to the general public, they have some uses in suppressing livestock prey drive in certain dog breeds but should never be used for normal training.

  2. This setup is pretty lousy from radio perspective. The cheap walkie-talkies, at least in Europe use single, common frequency of 27.145MHz, and the transmitting end effectively acts as a jammer for this frequency.
    As for PMR446, there is a rule (enforced by hardware) of transmission time limit of 60 seconds. Nowhere to be found in cheap walkie-talkies.

  3. Yes, the constant key transmitter in not ok.
    I would rather see something like the 555 is triggered by the incoming signal, to drive~pulse an audible beep or chip function. Any reason you couldn’t use a 556 to be the trigger and the “noise” driver? Would save some space and help keep the project size more manageable.
    You could always include some of the beloved blue LEDs to the audio response, for dim light conditions.

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