Home Is Home: The Physical Practicalities - Smart Home Automation with Linux and Raspberry Pi - page 137

This can be made to start at every boot by editing the /etc/default/nut file. You can then query the state of a
given UPS and check that it's working by issuing the following command, where apc is the name given earlier:
upsc apc
The output is something like this:
battery.charge: 100
battery.charge.low: 10
battery.charge.warning: 50
battery.date: not set
battery.mfr.date: 2009/01/21
battery.runtime: 705
battery.runtime.low: 120
battery.type: PbAc
battery.voltage: 13.5
battery.voltage.nominal: 12.0
driver.name: usbhid-ups
driver.parameter.pollfreq: 30
driver.parameter.pollinterval: 2
driver.parameter.port: auto
driver.version: 2.2.2
driver.version.data: APC HID 0.92
driver.version.internal: 0.33
input.transfer.high: 266
input.transfer.low: 180
input.voltage: 242.0
input.voltage.nominal: 230
ups.beeper.status: enabled
ups.delay.shutdown: 20
ups.delay.start: 30
ups.firmware: 829.D2 .I
ups.firmware.aux: D2
ups.load: 49
ups.mfr: APC
ups.mfr.date: 2009/01/21
ups.model: Back-UPS ES 700
ups.productid: 0002
ups.serial: 5B0904T46000
ups.status: OL
ups.timer.reboot: 0
ups.timer.shutdown: -1
ups.vendorid: 051d
It is possible to have several UPS units controlled by a single server. This is usually beneficial because it allows
your master server to handle all the system administration tasks, giving a single point of entry to the home network,
which can be hardened as appropriate.
Having gotten the machine to shut down, you need a way of making it start up again once the power is back on
full time. This becomes a hardware problem, and success is governed by whether there is an option in the BIOS to
start up on power or similar. In the case of the NSLU2, you can physically hack the circuit board to perform the same
task. It is also theoretically possible to hack the switch in a standard PC in a similar fashion, but it's not recommended.