Transmit data (and signed transactions / invoices) over the air-waves using DTMF technology.
A project for the 2023 SatsXSouthwest hackathon.
https://twitter.com/PlebLab/status/1637576743216201731
Transmit https://supertestnet.github.io/satoshi-jump/transmit.html
Receive https://supertestnet.github.io/satoshi-jump/receive.html
Get a pair of walkie talkies (or just hold your transmitter's speaker near your receiver's microphone), hold the push-to-talk button while one of them is near your transmitting computer and the other one is near your receiving computer, and hit Send. You do not need to hit the Receive button, that button is only there for visual flare, it does not actually do anything -- the receiver is always listening and we just transmit "control codes" to tell it when to start logging what it hears.
Also, make sure your message is relatively short because about 1 in 10 characters is misheard and we haven't added error correction codes yet.