A(n im)possible battery gauge
- Details
- Created on 04 Jun 2011
- Last Updated on 04 Jun 2011
While doing research about the Magic Trackpad, I found that there is a battery indicator on Mac OS X. So there should be an easy way to receive the battery info under Windows as well, in theory.
The next logical step was to look at the Human Interface Device (HID) level which is still system independent. Querying the HID infos from the Magic Trackpad did only offer standard mouse infos. OK, HID is a bit complex but well defined. So digging in HID documentations I found a general battery info descriptor, but it's not there.
More or less by coincidence I did uninstall Apples trackpad driver to test something else. Unaware of the trackpad driver not being installed and running the HID queries again: Surprise, there was the battery info where it should be. It was quite simple to receive the battery info by request.
And another surprise. Without Apples driver the HID infos had suddenly much more to offer. I'm not a HID expert and there is a lots of vendor specific info.
But one thing is for sure: Apple deliberately hides plenty of HID infos if their Windows trackpad driver is installed.
I'm really sorry, I can't extend the Control Panel with a battery gauge. It would only work without Apples trackpad driver installed.
Thanks for all the fish Steve!