Look into asterix
https://www.voip-info.org/asterisk-paging-and-intercom/
You should be able to pick up voip phones relatively cheaply these days with all of the commercial offices going to remote.
this post was submitted on 07 Oct 2024
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That looks pretty good. Looks like a lot of information to parse through, reading up now, thanks!
But you need to know where your family/friend are. Or can the system broadcast to multiple locations?
I saw some companies develop modern walkie talkie solution without wifi nor mobile signal for emergency rescue or expedition. But they are expensive.
Well in my scenario, both locations would be fixed, so I'm not really concerned about finding locations.
Yeah that's the problem, there are corporate options for corporate prices, but home intercoms have more or less disappeared with the advent of cell phones that everybody just has on them anyway.
I just put Amazon devices in most of the populated areas of the house and use broadcast, but honestly we rarely use them it's a lot easier just to text somebody.
One might consider getting some older phones mounting them in locations bringing power to them and running walkie talkie software.
expanding on this, depending on technical skill level:
i’d probably get some SBCs like raspberry pi (or cheaper; raspberry pi is probably overkill here!) to be the terminals, run asterisk and have an extension for each terminal… run a voip client that automatically picks up any call it receives, and connects to a mic & speaker, connect a button to GPIO and write a script to call a conference extension for all devices (or multiple buttons for multiple extensions to call individual locations)… i’d probably add a second button for a “call back”-like feature - a terminal broadcasts a message and there’s a button to reply only to the terminal the last call was from
this would allow you to use phones as terminals too - even receiving “calls”, although in that case the caller would have to wait for the phone user to pick up - just like a regular phone. probably more useful as a transmitter
all of these things aren’t super difficult in isolation - probably setting up asterisk is the hardest part
Or just bury another line. Connect to speaker to each end, put a small mic/amplifier/push button on each end
;)
The ESP32 is a pretty versatile chip. Here's a walkie-talkie someone made from one
Esp32 is very suitable but they jumped through a lot of hoops to recreate the ESP audio development boards you can buy for very little money with all of those parts already built in.
Ooh, name me some please!
I was just thinking of the likes of what you get for searching for esp32 audio kit on AliExpress. About us$12. Has microphones, amplifiers, buttons etc.
You've already run wires, why not a microphone and speaker system?
I could I guess? What would that look like? Just mic and speakers wired over Ethernet and just always on but with a hardware switch or something? Or connected to something like a Raspberry pi running some software to talk with the other pi?
From Amazon, I found "IS543 5/4/3 WIRE INTERCOM STAT-PLAST"
It's similar to what we had growing up, 1 in the shed, 1 in the kitchen 1 in the game room, push the button of the location you wanted to talk to, only 1 direction of communication at a time, over.
I feel like you're making it way more complicated than it needs to be, why would you involve a switch or processor when you're just carrying sound waves? You don't even need a modulator, it just needs to connect a microphone to a speaker like cans on a string. Is it the highest quality? No, will it record your conversation for posterity? Also no. Will it let you tell at someone to get their asses in for dinner, absolutely
Oh I'm sure I'm overcomplicating it. We had some landline phones growing up that could also ping and "intercom" but those were all connected to phone jacks with an active phone service, ao I figured I couldn't really do that. How is some like the one you mentioned wired? How does it talk to the the other one? Forgive my ignorance.
And to note, I definitely do not need high quality, just something local that is functional.
It's literally speaker wire, or you could clip the ends of your Ethernet and use those (but you probably want your Ethernet out there still XD. One side will be to be run to power, but it'll power the rest of the stations through the wire.
I feel like this is definitely what you're looking for, no computers required.
That's fair, and yeah in hindsight would have been great, though tough to retrofit. Maybe I'll look into running another line for something like that. Thanks!
Did you run the line under ground or through conduit? Disconnect it from both sides, attach string/fishing line to one side, pull cable out of conduit on the side without the string attached. Detach string from either meet cable, reattach string with Ethernet cable and the additional cable (speaker cable in this case), pull string from the original side until both cables make their appearance.
Outside of walkie talkies (have you considered walkie talkie? Maybe put an antenna outside of the shop?) this is the simplest way to do it (imo, but I don't play with raspberry pi's)
Against some better judgement, I did direct burial. I did consider walkie talkies, but heard doesn't work well in a metal barn (I confirmed I basically have zero cell reception). I could look at adding the antenna though, thats not a bad idea.
If you can find landline phones with that feature set, just get them. You can just wire them together and put 20 volts DC in the line. Of course you're not going to want to do that over your single ethernet run but if you had multiple...
Telephone services really simple, 18 to 24 volts on hook should pull down to about eight or nine volts when you open the line. If you pulse a 90 volt signal, It will cause them to ring.
one of the benefits of using a packet switched solution is that it’s expandable in the future… adding extra terminals anywhere there’s networking is pretty powerful - you can change your mind about location, or even technology in general and not have to worry
… and it’s probably much easier to extend on in the future too - say open source AI assistants get better, you might want to build one that integrates with timers etc, that’s much easier with packet switched … or even more likely, you want to broadcast to the intercom from outside your house or even just make mobile phones able to be transmitters inside the house
you’re totally right that simple point to point intercom stuff like that is a much simpler solution, but packet switched is king for a lot of future-proofing reasons - perhaps not something that OP cares about (a project completed is better than a perfect plan not begun), but worth mentioning
I'm just being pedantic here, but an intercom system expands anywhere there's networking, requires fewer wires, and lower voltage (will even work without power, not very well, but it will)
Could go old school and build your own:
Page 66: https://www.worldradiohistory.com/AUSTRALIA/Electronics-Australia/EA-1992-07.pdf
Page 126: https://www.worldradiohistory.com/AUSTRALIA/ETI-Australia/90s/ETI-1990-01.pdf
Look into Alphone, they have many different intercom products. I'm a low voltage electrician and could probably give you some actual companies to look into, besides Amazon.
If you have an ethernet cable out there you have quite a few choices, you could get voice/video very easily, or you can twist a few pairs together and get just voice. Truly depends exactly what you want.
Aiphone has a phone app, which can be run entirely locally which is what I prefer. Fuck cloud solutions.
I appreciate the info and the offer! I won't be messing with the Ethernet since that's used for networking. I was mainly looking to hook up an IP phone or something easy, but assumed I couldn't just connect that to my network and needed something so the two phones would tie together.