NUT UPS
Network UPS Tools, or NUT, is a daemon for Linux (et all) that monitors a UPS and can do funky things like shutting down your computer when it's run out of juice.
A friend bought me a UPS because I kept complaining about the power outages in the backwater place I live - more yay.
The problem was, the supplied CD only had support for Windows, and the computer that needed protecting was my server, which runs Linux. Fortunately NUT comes to the rescue - well so I thought.
My UPS came with a USB connection and not an old-fashioned (but perfectly easy to use) RS232 connection. So when I plugged it in to my Linux box, set NUT to use USB and hit go, not a lot happened.
Exploring my UPSilon UPS (also packaged as Belkin) I find the USB hardware identifies itself as:
Device: MEC0002
Model: Fry's Electronics MEC0002
And helpfully uses the HID (Human Interface Device) driver.
When configuring your ups.conf you will fooled into thinking that the "usbhid-ups" driver is the one for you. It isn't. Some searching of the net will inform you that you want to use the "megatec_usb" driver instead. Although if you're like me, you'll find that this is missing. A little searching through comments in source code lead me to the new "blazer_usb" driver, this hits the nail on the head.
I say nail on the head, NUT now recognises a UPS. As my server is currently unwilling to boot, I'm too afraid to see if I can get it to do anything clever (like shutdown my computer), but I am get voltage readings back ok.