Friday, April 10, 2009

Noise filter your signals!

Free advice. When there's a 200m loop of wire carrying a low voltage signal, noise filtering is a _very_ good idea.

Otherwise the doorbell may ring at 3am in the morning from induced noise...

Sunday, April 5, 2009

'Fixed' the doorbell today.

The doorbell has been a source of trouble for a while. Mostly because D is in the habit of closing every between where she is and the front door, causing it to be inaudible.

So today, I wired the doorbell between the DCD and DTR lines on the main fileserver and wrote a little C program effectively gets an interrupt when DCD changes. When triggered, this program runs wget to hit a URL on another server, that runs a cgi-bin script, that plays a .wav file through the speaker.

For some reason the name 'Reuben Garret Lucius Goldberg ' kept running through my head...

But the end result is that one can push a door near the front door, and something near the center of the house chimes, so the end goal is fully achieved!

Saturday, April 4, 2009

Clipsal C-Bus

Clipsal have decided to open the C-Bus protocol.

Speaking as someone with a C-Bus wired house (for reasons that were never terribly good), this is a very, very good thing.

It's rather unexpected, and I suspect a little late (there's considerably more competition around now), but it's going to make it much easier to do semi-decent integration.

Yay Clipsal!