[Swansea Hackspace] TechHub Buzzer/Access Project

[Alan Cox]

On Tue, 4 Nov 2014 12:58:03 +0000
Paul Harwood <paul.harwood at techhub.com> wrote:

> Hello,
> 
> I did mention this a while back but now it's getting a bit more desperate...
> 
> TechHub has a requirement that you can probably help with when you next meet if you want. We can pay associated costs but we really need to swap our buzzer handset for a portable one or something we can attach to - a chat client - a web page - - or a n other thing that could be portable - the world is our oyster. The set we have is a BELL 801 Issue 5 - cable connecting it is CAT-5E. I don't want to break this set but rather replicate it's functionality.

Somewhat non trivial for the voice parts as the voice signalling on it is
analogue. You've got a 12v call button connection (not too hard to wire),
a lock button wire (ground to common when pressed) and a lock monitor in
some cases (just drives an LED), oh and the expected 12v/0v

The microphone and speaker elements are pure analogue phone so you'd have
to use something like a VOIP box and re-code them then stream them over
ethernet or wifi (and voice over wifi always sucks)

A microcontroller monitoring I (V is 12v (ac or dc) O is the common, I is
the call button) might do some of the job I guess. They've even
thoughtfully left you some screw terminals and space in the case for it 8)