Emacs Light Switches

Tellstick Duo

Telldus launched a new version of their nifty USB-based “home automation” thingy a couple of months ago.  It’s mostly the same as the last version, but this one can receive signals as well as send signals.

This means that you can buy stuff like this switch, glue it onto a wall somewhere, and control your lights more like a normal person.  Instead of having to use computer-ey interface.  Like an animal!

It works pretty well.  As before, the USB interface exposes a serial interface. To get it working under Linux, you need to tell it about the serial numbers, because this devices is brand new:

[larsi@quimbies ~]$ cat /etc/modprobe.d/tellstick.conf
options ftdi_sio vendor=0x1781 product=0x0c31

After doing that, the device shows up as /dev/ttyUSB0, and if it receives something, it spits out data like

Wireless Wall Switch Sticky-Taped On To The Wall

+Wprotocol:arctech;model:codeswitch;data:0xE47;

So you basically just stick lots of switches on the wall, and then create rules to respond to these strings.

I’ve updated the Emacs code.

It seems to work pretty well.  There range is OK — it kinda goes through one wall, and kinda works over 7 meters.  But it’s not 100%, which is annoying.  I’ve bought two devices, so far, to get coverage over the flat, but I think I might need one more.

Anything that’s wireless sucks, but being able to just glue switches anywhere is pretty awesome.

Leave a Reply