ePaper (eInk) Touchscreen in Android 11

General Discussion
#1

Project guidance will be greatly appreciated.

I´m developing a touch keyboard for a specific therapeutic application that can´t use a LCD/OLED/TFT screen (because of the light emissions). ePaper Displays (EPDs) with capacitive touch overlays add a level of complexity from their integration plus the associated libraries are available only in C.

As an alternative, I found an ePaper notebook that runs Android 11 and, after interacting with their product support, they confirmed that it can load and run 3rd party apps.

I´m somewhat versed in C++ and Python and I´d rather sweat it out with C libraries than going into the standard Android development framework. Choose the lesser evil.

This is where MIT AI could be a lifesaver if it can manipulate an ePaper touchscreen. Refresh rate (usually an issue with EPDs) is not a problem for this use case (very slow typing and some feedback).

I build this prototype using a microcontroller to test the letterboard concept in the associated therapeutic environment (autism).

The ePaper notebook I found is the Onyx Boox Note Air 2 Plus

Many thanks for any and all comments!

1 Like
#2

It's just a regular notebook with a slightly different display. All standard android apps will work on it, so you can easily create a working app in AppInwentor.

#3

@Patryk_F Thanks!

When creating a new project, I see that the largest screen size, using Monitor Size, is 1024x768. The notebook's screen is 1404x1872 (227 ppi & 16 shades of grey). Do you know of a way to access the full 1404x1872 of this device?

I won't be loading an image of that size (!). I just want to access the full screen to design the keyboard and the feedback prompts.

#4

See
http://appinventor.mit.edu/ai2/responsive-design-app.html
and
http://imagnity.com/tutorials/app-inventor/universal-screen-size-using-app-inventor/
from

#5

@ABG Thanks! A lot of info on screens! Particularly useful your FAQ Section! :clap: :clap:

The design based on screen %'s is what I've used for UI's in Windows. My question perhaps is more towards how AI2 (or Android) manages the device driver (I'm a complete noob in these two).

I see that "... App Inventor’s Screen has width and height which are the width and height of the actual device…".

The actual device (in this case) has bigger dimensions than the apparently largest possible screen size (selected when creating a new project). Is this initial selection just a reference? or are these numbers (1024x768) hard coded?

What I mean is, for example, if a screen element uses screen.height * 0.10, will it use 768 x 0.10 or 1872 x 0.10?

I can't experiment on the actual device (which would be the correct thing to do) because its purchase depends on the possibility of using the full screen in AI2.

Thanks!

#6

Just pick which of the 3 AI2 Design Screen options comes closest to the height/length ratio of your device, and can fit onto the screen of the laptop/desktop you will use for your layout work.

If you follow the responsive design principles (per centages only), your GUI should stretch to fit whatever you run it on.

If you plan on using your homebrew keyboard with the epaper notebook, check what level of BlueTooth the notebook can support.

1 Like
#7

Thanks! I´ll go ahead with the notebook purchase and start experimenting!

#8

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