Battery indicator in PC

[kiddykoff]

I setup Ubuntu 11.10 for my girlfriend a while back and recently I noticed something cool. When she was charging her Itouch via USB there was a battery indicator of the USB device under the indicator for her Laptop battery.

I looked into it and this is what i mean:
https://wiki.ubuntu.com/Power?action=show&redirect=BatteryStatusMenu#Battery_menu


I don't think she has installed anything to do this, so the operating system must be listening for messages from the device. Is it possible that Rockbox could do this?

[bertrik]

As far as I know there is no standard protocol to query the charge status of an attached audio player, but apparently apple made their own way of doing this. I think they use some kind of special SCSI (over USB) command for synchronising the time, perhaps they use the same mechanism for getting the charge status too.

So, someone need to figure out how they do this and the have a look if we can emulate it in rockbox.

[fuflo]

isn't it part of mtp protocol? I saw the same on my sansa clip. If connected over mtp, i get battery level in windows for the device. I might be wrong, haven't used mtp at all for a couple of years. Just this topic caught my attention.

Also a quick searching gave me this:

http://www.linux-magazine.com/Issues/2009/104/MTP-in-Linux

Code: [Select]

09 MTP-specific device properties:
10    Friendly name: superk
11    Synchronization partner: {64DAA456-CB9A-4FED-905C-6674746D2C1C}
12    Battery level 93 of 100 (93%)

Listing 1 is just a brief snippet of the output produced by mtp-detect, which not only detects the device but also lists the types of files the device can handle, as well as other attributes like the battery level.

[gbl08ma]

I was going to post something else but fuflo already did a great research job... in that case, Rockbox would need to implement MTP instead of simple mass-storage for battery level reading to be possible. Too bad I don't like MTP... or just put a setting so we can switch between the two like on the Sansa's OF

Jokes apart, I don't think mouses that report their battery status use MTP just for that. Must be some other protocol (which eventually is easier to implement in Rockbox).

[nls]

I'm fairly certain that apple's istuff don't implement mtp so it's probably some other mechanism, anyway i'd say the chances of rockbox getting mtp are slim.

[gbl08ma]

Probably every device implements the battery level reporting its own way and it's the OS drivers that need to do the job of finding the battery level for the device they drive. There's no standard for battery reading or time syncing through USB as far as I know.

[bertrik]

With mtp-detect indeed I *can* get a battery reading from a clip zip in the original firmware MTP mode, but I don't see it show up somewhere in the ubuntu GUI (I even tried with a compiled version of the most recent libmtp-tools)

[gbl08ma]

What Ubuntu version are you using? Are you using Unity? I have a feeling this battery freshness is only available in 11.10... and perhaps only for Apple devices