Homebrew Telephone Exchange Keeps The Family In Touch, In The House And Beyond
It doesn’t take place typically, but each and every after in a although we stumble on somebody who has taken out of date but truly interesting telephone-switching machines and designed a personal switched telephone in their garage or basement making use of it. This private analog mobile phone trade is not 1 of people, but it’s nonetheless a super great build that is likely about as bold as having an aged phase-by-step or crossbar swap working.
Ideal up entrance, we’ll stipulate that there’s totally no functional explanation to do some thing like this. And hacker [Jon Petter Skagmo] admits that this is incredibly a great deal a “because I can” project. The idea is to help a bunch of previous landline phones distributed close to the household, and further than, in a type of glorified intercom technique. The private trade is completely scratch-created, with a PIC32 acting as the coronary heart of the technique, doing this kind of responsibilities as DTMF decoding, producing ring voltage, and even offering a CAN bus interface to his residence automation process.
The principal board supports 5 line interface daughterboards, which join every telephone to the change via an RJ11 jack. The interface does the get the job done of detecting when a cellphone goes off-hook, and does the precise relationship concerning any two phones. A separate, specific interface card presents an automobile-patch capability applying an RDA1846S RF transceiver module with it, [Jon Petter] can link to any cellular phone in the technique from a UHF useful-talkie. Check out the video clip under for extra on that — it is very neat!
We just like anything about this overengineered project — it is clearly a labor of love, and the fit and complete truly reflect that. And even nevertheless it is not strictly old college, POTS assignments like this usually place us in the temper to observe the “Speedy Cutover” video a single additional time.
