[Noisebridge-discuss] door to gate intercom

[Jake]

last night I made a two-way audio intercom to go between the upstairs door 
area and the gate downstairs.

yes, technically there was already an intercom but it was a low audio 
quality useless piece of crap, and one direction wasn't working at all.

the new intercom uses apple plaintalk microphones which are high-quality 
condenser microphones with a built-in preamp.  They send line-level audio 
through a cat5 cable in both directions.

there is a microphone and speaker mounted at the gate (i didn't witness 
the installation but the wiring was done when i left for BART) and a blue 
cat5 cable runs from the gate to the camera monitor by the upstairs door. 
At the monitor there is another microphone and speaker, and it's all 
powered by the 12v from the monitor.

The amplifier which boosts the microphone's line-level outputs to speaker 
level is part of the monitor, and one channel is used for each direction.

There is a volume knob on the left side of the monitor, toward the top. 
If the volume is turned up too far, there will be feedback.

If you notice a problem such as the wire is dangling into the door hinge, 
or the speaker needs to be zip-tied into place, or the speaker and 
microphone are too close to one another, or anything else, please do 
something about it and/or let me and/or the list know.

i hope everyone enjoys the ability to communicate clearly between the gate 
and the upstairs door.  Once this system is working well enough, we can 
disable the doorbell and replace it with a sign that says "to get in, 
please announce your request to the microphone so that you can be heard 
upstairs."

-jake