No Strings Attached: The World's First Wireless Tin Can Phone
A new take on a very old idea.
As a kid, you may have tried to create a “telephone” with cans and a string, supposedly transmitting audio signals through the connecting fibers. Results were probably not great, and by design each had to be physically linked to each other. This build, however, by Geoff at Facio Ergo Sum appears to work much better, embedding actual radio equipment inside a pair of tin cans for enhanced communication capabilities.
As seen in the video below, the project starts out by sourcing a pair of cans, then poking a hole in the bottom for an arcade-style talk button, along with another for a small antenna. Inside of each can is an Arduino Uno, IO expansion shield, speaker, audio amp, microphone, and perhaps most importantly, an nRF24L01 radio unit for signal transmission.
Everything is hooked together with jumper wires and stuffed into the containers. Program-wise, it’s very simple — using the RF24Audio library for audio transmission. Transmission is started in the setup, and there’s actually nothing at all in the loop section of the program. If you’ve never seen the nRF24 used for actual audio communication, this could be a good thing to keep in mind for future projects.
After securing everything with hot glue, Geoff tested the system at a “social distancing” separation, and later successfully demonstrated much further away on the side of a small mountain/foothill.