[Likebook Mimas] Remapping volume buttons to page up/down

[StuartJ]

One of the things I like about the Mimas is the physical page turn (actually volume) buttons, which work great in the built-in reader and also in e.g. Pocket and Moon+ Reader. Since they are actually volume buttons though, they don't work in other apps, and e.g. I wanted to use them for page down in Kiwix or an internet browser (but the only internet browser I found that supported navigation with the volume buttons was Dolphin and I preferred Firefox). I hardly need to change volume on the device at all, so wanted to remap these to page up and down - and, after trying all sorts, I finally got it working and thought I'd share, in case this is useful for anyone else.

What worked for me is to use Button Mapper. Caveats:

1. additional setup required. Because no-one has (yet!) managed to root the Mimas, you need to do an additional setup step using USB debugging - see https://setup.buttonmapper.app. You also need to repeat this each time the device is rebooted - which is a bit clunky, but I can live with for the moment.
2. you need to buy the Pro version of the app to remap buttons to send key codes, but for the cost of a cup of coffee, it was worth it for me.
3. The app isn't designed for e-ink. I found I could just about see what was going on with the dark grey on light grey lettering if I cranked up the light to maximum brightness. Your mileage (and eyesight) may vary..

If you do go ahead and install (and pay for) Button Mapper, you can then remap the volume buttons. I remapped:

1. volume up: single tap to keycode 92
2. volume down: single tap to keycode 93

... and now I can use the 'page up/down' buttons more or less everywhere! Well at least in all the software I'm using: Firefox, Kiwix, Calibre Companion, Pocket, Moon+ Reader and the Boyue PDF reader. So far so good

[Istrain]

I've used that app before on phones but I am hesitant to install proprietary apps with tons of permissions, in case they negatively impact the device somehow. But if the battery is okay then perhaps it's not a big deal since eink ereaders are not updating screen fast enough to warrant using internet often, which is the area of concern for most apps. Keep in mind these batteries cannot be replaced. My onyx died for ex.

[MustardOrMayo]

I believe Boyue set it up like that in order to have apps already be able to support the page turn buttons when their respective "Page turn using volume keys" features are enabled. Page Left is Volume Down, and Page Right is Volume Up.

This works for me in most reading apps I use (list excludes those that use a continuous format):

• Kindle
• Kobo (haven't purchased anything there yet, but I had tested using samples)
• Tachiyomi
• Comixology (haven't purchased anything there yet, but it should theoretically work)
• Moon+ Reader Pro
• FBReader
• KOReader
• Likebook built-in reader (obviously)

However, in OverDrive Media Console, the keys end up getting inverted (so Page Left goes to the next page, and Page Right goes to the previous page), and in Libby by OverDrive, it doesn't support page turns using volume keys at all, but as I confirmed on my tablet (because Likebook uses a non-compliant USB-C implementation that does not support OTG at all), I can still turn pages using the Page Up and Page Down keys on an external keyboard, and I can do the same using the web version of the Libby reader component (the one launched from the web interface of the library's OD instance (library_name.overdrive.com) and from the library's own mobile app (if they have it; I'm a member of a library that has one)) on my PC.

I had been considering getting my Mimas apart in order to fix an issue with interference being spit out of the earphone jack, and also to see if I could hack the display controller (part of the reason why I got the Mimas was because it was cheaper than the official E-ink dev kit, plus I could run XSDL early on to develop and then move on to writing directly to the display controller, but it got me further into the world of comics and I enjoy that), but also in order to find a way to hack in USB hosting and to get the RK3368 in the Mimas into "mask ROM" mode (that would then lead to work to get custom ROMs running on it), but never got around to doing so as I'm rather busy.