Wireless Tin Can Telephone

For many kids, the tin-can telephone is a fun science experiment that doesn’t last much longer than it takes to tangle the string around a nearby tree. [Geoff] decided to go a different however, building a tin-can telephone that’s completely wireless.

The build starts with a hacker favorite, the Arduino Uno. It’s hooked up to an microphone input board which uses the Arduino’s analog input to pick up audio. The Arduino then sends this data out over an NRF24L01+ wireless transceiver, to be picked up by the corresponding tin can receiver at the other end. An LM386 is given amplifier duties, hooked up to a small speaker so the user can hear the incoming audio.

The Arduino Uno is in no way a high-fidelity digital audio platform, but the project does deliver some legible, if scratchy, voice transmission. It also serves as a great way to learn about radio communications and working with digital audio signals. The NRF24L01+ is a great way to add wireless communication to a project, and if you’re looking for more range, we’ve got that covered, too. Video after the break.

19 thoughts on “Wireless Tin Can Telephone

  1. When I was a kid, I had a pair of futuristic tin can telephones.

    They were like tin can phones, with string between, but instead of cans, they were plastic. I want to say they were shaped like “rayguns” but maybe futuristic walkie talkies. This was the mid-sixties.

    1. Now I had something like that in the 70s, some spacey raypunk type shell but they had a plastic diaphragm in, and about 15ft of really thin tube that connected the two, you really had to yell down them to hear anything though. The performance improved when the tube got all mangled and flattened and a parent linked the diaphragms with string that you had to pull tight in tin can fashion.

  2. When I read the title I was thinking something along the lines of a high voltage electric arc against the bottom of the can, so speech vibrating it modulates the signal. Then you basically have a really simple receiver, no tuning necessary, to receive the spark gap transmitter signal and a switch to toggle between receive and transmit.

    1. Not only convenient for the pocket, but also unlikely to roll if you set them down on a slope, extremely well thought out.

      you were waiting for the /s weren’t you? …. well there it was, damn, gotta end the whole thing with it? /s

  3. Quote: “It also serves as a great way to learn about radio communications and working with digital audio signals.”

    How so? I don’t think there’s that much to learn from copy&pasting the example code from an Arduino-library and hooking up some breakout boards.

    Anyways, I don’t critisize the project itself which is nice and fun, but I don’t think it is very educational to learn about radio or digital audio processing.

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