Dear All, I am investigating the ACPI events associated with power source changes.
My first observation is that the "alarm" file in /sys/class/power_supply/BAT0 is not functional, due to a limitation in the BIOS and perhaps also in the hardware. So to implement a low battery alarm you need to poll the charge_now file. Looking at the ACPI events when I connect and disconnect the power, there are quite a few of them. Here's disconnecting: battery BAT0 00000080 00000001 ac_adapter AC0 00000080 00000000 ac_adapter AC0 00000080 00000000 battery BAT0 00000080 00000001 hotkey ATKD 00000051 00000001 processor P001 00000081 00000000 "ac_adaptor ... 0" seems to be the thing to look for if you want something to happen when the mains goes away. But beware: you need to cope with there being two events, and note that /sys/class/power_supply/BAT0/status is not perfectly in sync: a script may observe that the mains has gone but the battery is still charging! (Oh, and you need to agree about how to spell adapter.) When the power comes back I see: ac_adapter AC0 00000080 00000001 battery BAT0 00000080 00000001 hotkey ATKD 00000050 00000001 processor P001 00000081 00000000 battery BAT0 00000080 00000001 ac_adapter AC0 00000080 00000001 so "ac_adapter ... 1" indicates that the mains is back, obviously. Finally, I let my battery run out to see what happens. I wasn't expecting to get anything, but I actually saw this left in the xterm as the machine shut down: hotkey ATKD 00000052 00000000 and a battery line which I foolishly didn't copy down, but was I think another "80 01" line. I wasn't looking in the right direction at the time so I don't know exactly how long before it failed this appeared, but I think it was immediately prior. The mains on/off logs also have hotkey events with codes 50 and 51 respectively. Do we have any document anywhere that describes what these various hotkey codes mean? Perhaps these are the codes that I should be using. As you can probably guess I'm putting together a low battery warning thing. The other side of the problem is what should happen in response to the warning. Any suggestions about this would be welcome. Cheers, Phil. _______________________________________________ Debian-eeepc-devel mailing list [email protected] http://lists.alioth.debian.org/mailman/listinfo/debian-eeepc-devel
