A few months ago, an uncle of my wife asked me to help them modernize their IT. Well, “modernize” means: Install a computer in the first place, with Internet. So, given the best price/performance they could get was getting fibre, i told them which plan was most interesting for them with their preferred provider, built them a Ubuntu machine, set them up a domain name with associated info@ and called it a day.
I just – falsely – assumed that moving over to VoIP would be no big deal because you can attach your old handset to the FritzBox (the ISP provided router, which includes VoIP functionality. I don’t like FritzBoxen much, but they do have a lot of functionality for the classic home user. Anyway… The providers goons come on-site and it turns out that their telephone system is “not conform”, and that’s the nice way to put it.
Basically, what he didn’t tell me is that years yonder when he was just a mere apprentice and his father was the ruler of the company, the telephone company (monopoly, back in the day) did some hacks so a bell would sound in the workshop. You know, that was kinda possible with 5V on the lines. I admit, it was my mistake for not asking. I kinda, should have suspected that a carpenter isn’t in his office all the time. On the other hand, he might have told me about these things beforehand. My suggestions would most likely have been different.
There are some other really bad hacks on their installation, but I told them to fix that with the phone company and it is mostly to do with sharing the line between a habitation and the workshop. You gotta separate those two, if only because it’s a pain for customers calling you and Grandma picking up the phone.
Of course, the damage is done. the interwebs work, but their phone system doesn’t any more. The normal handset doesn’t ring any more, and the bells in the workshop, make a rattling noise at best.
My best bet is to replace their handset with a SIP Phone (I have snom 710 myself and they’re rather decent and interoperate perfectly with the FritzBox)
However, I have no idea what to do about the workshop ringer. Commercial SIP ringer exists, they just cost 250EUR++, which is, frankly, highway robbery. Ideally, I’d just put decent voltage on the existing wires, when there is an incoming SIP call. Detecting an incoming call could be done with a Raspberry Pi. Up to there, I’m good.
However, that’s the thing: I’m not a hardware guy. Yes, I assemble computers and can do small things, but I have no idea how to tackle this. What I understand is that I’d need to control a relay, somehow. GPIO, or USB. I simply don’t know and Googling seems to yield stuff from people who know what they’re doing. Not very helpful to me.
Alternatively, could get one of those USB gizomos. Put a CAT5 into the workshop, attach RPi to CAT5, attach gizmo to to RPi. Activate upon incoming SIP call. Something like that.
Really, this goes beyond my expertise, so perhaps any of you have better ideas or product recommendations?