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.
Just a bit of a correction “[Geoff] decided to go a different however” probably wanted to be “[Geoff] decided to go a different route however”?
Or, if not, a different what?
I thought they’d use the cans as directional antennas.
Make a wireless tin can telephone that uses a tin can for both audio and as an antenna
Attach a second can for the antenna and call it a “Toucan Phone”
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.
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.
Should that be title be ‘Stringless Tin Can Telephone’?
I think you could make a good case for that.
I like it! Maybe I’ll update it :)
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.
Eugh what does it have to do with social distancing? It’s basically just a walkie-talkie using a coffee can as the enclosure, right?
it’s known as a joke on planet earth. Maybe have a look here: https://en.wikipedia.org/wiki/Humour
I cannot conceive of a better form-factor for this project. Bravo.
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
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.
I remember well my tin can phone. Great mystery how it worked, loved it as a kid. Does the electronics take that mysteery away?
Kids these days… https://forums.qrz.com/index.php?threads/voice-powered-14-mhz-transatlantic-test-on-tuesday.224828/
Yes, an entirely voice powered transmitter and they have communicated over some very impressive distances.
Wow, I was pondering when the article posted, how easy it would be to make a voice powered one that had noticeably greater range than just yelling.