I am working on a project that uses an e-ink display connected to a board that runs a linux version using SPI. I can now control the display fine from user space but what I would really like to do is make a display driver so the e-ink display is seen as a normal display by linux. I have searched online on what I would have to do to make this work but I can't really find anything.
Could someone point me in the right direction?
Please have a look at the existing "fbtft" drivers here. Some Waveshare driver seems to be already supported and it might be what you are looking for or you can add support for the one you want. You can also have a look at the out of tree fbtft and tinydrm driver repository.
Related
I have been trying to build a TV application, using an SD.
I have got features like image gallery, video player running,
However, I also wanted to add a virtual on-screen keyboard that works with up-down left-right arrow keys. Can somebody help me with how to get started?
When I wanted to do this with my Vestel (Polaroid Branded) smart TV, which uses "Opera for TV devices" as it's HbbTV browser, I found that I didn't need to.
I simply just used HTML text fields and input types where needed, and as soon as I clicked into them, the browser/OS kernel popped up an onscreen keyboard that was built in for me.
However, I did do some research to see if I needed it, and on some devices you do, whilst I never actually implemented it (My app was just for my own use) the "BBC Television Application Layer" (TAL for short) : https://github.com/bbc/tal had pretty good keyboard support.
Another one that might be worth looking at is "Mautilus SDK" : https://github.com/mautilus/sdk
Be aware though, both are horribly convoluted and use quite complex code where it's really not needed.
I've got a bit of an interesting problem here. There are plenty of threads I've found where people are working to hide or get rid of a cursor on an embedded Qt GUI...but I'm trying to get a cursor to show up on an embedded Qt GUI.
I inherited a project that was 'finished' some time ago, and the person who did the most work on the project has moved on. Fast forward to today and there is a need to add a cursor to this functional touchscreen GUI. The system OS is Yocto Linux, and it is running a Qt 5.4 application on a framebuffer.
I've scoured the Qt code and there is nothing there that would hide a cursor. I've added in the appropriate QT_QPA_FB_HIDECURSOR=0 environment variable to my Qt startup script. I've experimented with adding a QCursor obejct to the GUI. Unfortunately none of these things are working. Using the QCusor I am sometimes able to get a cursor up on the screen, but isn't tied to the touch input (the cursor shows up at the position I programatically move it to, but it stays there when I interact with the GUI).
My touch input events are tied into Qt (via QT_QPA_GENERIC_PLUGINS=evdevtouch and QT_QPA_EVDEV_TOUCHSCREEN_PARAMETERS=/dev/input/event9:rotate=180), but for some reason that touch input cannot be tied to a cursor.
At this point I've spent a few days messing around with environment variables and startup script modifications, but nothing I've done has got the result I'm looking for.
Does anybody out there have some ideas on where to look for solutions to this problem?
Thanks!
Ian
So, now 3 months later I think my team and I just came up with a passable solution to this problem.
The path towards the solution started with the Qt Documentation on "Using libinput". The documentation boils down to a few important statements:
Parameters like the device node name can be set in the environment variables QT_QPA_EVDEV_MOUSE_PARAMETERS, QT_QPA_EVDEV_KEYBOARD_PARAMETERS and QT_QPA_EVDEV_TOUCHSCREEN_PARAMETERS
The mouse cursor shows up whenever QT_QPA_EGLFS_HIDECURSOR (for eglfs) or QT_QPA_FB_HIDECURSOR (for linuxfb) is not set and Qt's libudev-based device discovery reports that at least one mouse is available. When libudev support is not present, the mouse cursor always show up unless explicitly disabled via the environment variable.
The evdevtablet plugin provides basic support for Wacom and similar, pen-based tablets. It generates QTabletEvent events only. To enable it, pass QT_QPA_GENERIC_PLUGINS=evdevtablet in the environment or, alternatively, pass -plugin evdevtablet argument on the command-line. The plugin can take a device node parameter, for example QT_QPA_GENERIC_PLUGINS=evdevtablet:/dev/event1, in case the Qt's automatic device discovery (based either on libudev or a walkthrough of /dev/input/event*) is not functional or misbehaving.
So, in my system I have the device nodes: event0, event1, event2, event3, event4, event5, mice, and mouse0. Because I'm trying to get the mouse working, I made the assumption that I'd have to use the mouse0 node. This lead to me setting these environment variables:
QT_QPA_GENERIC_PLUGINS=evdevmouse
QT_QPA_EVDEV_MOUSE_PARAMETERS=/dev/input/mouse0
Much to my frustration these environment variables led to nothing. After some time my team and I figured out how to get debug output from Qt source on our system:
Modifying source code in the qtbase directory under our yocto build (roughly /yocto/poky/build/tmp/work/temp build directory/qtbase
Copying qtbase/plugins/generic/libqevdevmouseplugin.so to my hardware (roughly /usr/lib/qt5/plugins/generic)
Running Qt from the command line
We quickly discovered that the input events coming from mouse0 and mice were basically garbage data. On our system we did set up EVDEV in the kernel, so the mouse input was also tied to the device node event0. When we tried setting the Qt mouse parameter to event0 we started to see debug output that looked like real data.
QT_QPA_GENERIC_PLUGINS=evdevmouse
QT_QPA_EVDEV_MOUSE_PARAMETERS=/dev/input/event0
However, the problem of no-mouse-pointer still remained. After a while we looked back at the Qt Documentation, specifically at the 2nd paragraph listed above. As a last ditch attempt we tried adding in the QT_QPA_FB_HIDECURSOR environment variable...
QT_QPA_GENERIC_PLUGINS=evdevmouse
QT_QPA_EVDEV_MOUSE_PARAMETERS=/dev/input/event0
QT_QPA_FB_HIDECURSOR=0
And...voila! After countless hours of debugging and reading documentation, we finally got a mouse pointer.
I think the main crux of our issue was misinterpreting the Qt Documentation.
The mouse cursor shows up whenever ... QT_QPA_FB_HIDECURSOR (for linuxfb) is not set
By "not set", Qt means explicitly defined as FALSE...not simply "not set" at all.
This solution will work for us, but it does leave at least one thing to be desired. Along the way I stumbled across this thread answer on the Unix StackEx which points to the Kernel documentation of input/input.txt. In section "3.2.2 mousedev" you can see the line:
Each 'mouse' device is assigned to a single mouse or digitizer, except
the last one - 'mice'. This single character device is shared by all
mice and digitizers, and even if none are connected, the device is
present. This is useful for hotplugging USB mice, so that programs
can open the device even when no mice are present.
What this means for us is that while we can use event0 (which goes away when we unplug the mouse) for our mouse input event handling, we won't be able to support hot plugging without making some kernel/Qt-source modifications or figuring out how to get mice working as a Qt mouse input parameter.
So, the question of "why does event0 work and not mouse0/mice" still stands...but for now we've got a solution we can live with.
UPDATE: Now a little bit later we've figured out that udev was not working properly on our system. We added udev to the RDEPENDS in our package group for the Yocto build, and now we can set
QT_QPA_GENERIC_PLUGINS=evdevmouse
and we get a working mouse pointer with hotplug support.
I dont know if this applies to your problem (i dont use QT), but there is a
HAVE_TOUCHSCREEN=1 variable in the machconfig file. It is located normally in your BSP-layer in a recipes-bsp/formfactor/formfactor directory.
Setting this to 1 makes the cursor invisible.
Try setting it to 0
I have a technical doubt on an ePub3 job and thought of checking with you all and get your understanding and advise on it.
For one of my German client, I have created a ePub 3.0 re-flow with interactivity, we have used all the interactivities to work on pop-ups (Non-linear content) and it works well on iPad iBooks 3.2, as the initial request from client is to work only for iPad.
I understand that a latest Apple spec (iBooksAssetGuide 5.1 Rev 2) now says that “Develop scripts that perform well on both Mac OS and iOS devices: Interactivity on desktop computers requires input from a mouse while interactivity on iOS devices require touch input”. I’m not sure whether there would be any problem while this job goes into the Apple iBooksstore, due to the latest spec.
It would be of great help, if you all please share your idea’s / view to this problem.
Regards,
John.A
Great question. With the latest version of OSX (Mavericks) running iBooks as well, there are a few things that need to be considered when using touch interactivity in ePub3 books. The most important (and relevant here) of these is making sure you are firing mouse events as well as touch events: because they behave differently.
The most robust solution that I have found to date is using JQuery or Quo's "tap" event: as it will fire with both touch and mouse events! However, if your code digs deeper (IE if you you use events like "touchstart", "touchmove", etc.) you will need to use the corresponding mouse events to insure functionality on the desktop.
Tap.js is a great little library for stuff like this: http://alxgbsn.co.uk/2012/03/12/tap-js-a-lightweight-tap-event-javascript-plugin/.
You should also be aware that iBooks for OSX behaves differently for many features (especially when it comes to external media content and dynamic loading of content), so you should never rely on OSX only when testing...
Good luck!
I'm going to develop a application in the company I work for, and I were asked to create a layout as an OS desktop, with applications, icons, shortcut and everything.
I've tried searching so far, but found nothing. My real problem is that I don't know what to search, I don't have a definition for what I need.
To understand butter, it's something like AirDroid or Glide OS (but no, i'm not using any flash).
Thanks :)
Edit
If someone is curious about this, I found this library:
http://www.sencha.com/products/extjs/
It was made exactly for what I need. :)
I have recently got a Mac and I have downloaded Xcode 4.2 from the store. I am trying to get to grips with iPhone development but I am having real troubles. All the tutorials I seem to find online, when they create a project, they had a resources folder, and inside that there is xib file which allows them to use an interface builder.
This does not appear on 4.2, so makes it kinda hard to follow majority of tutorials have the resources folder. How do I get this back? Or how do I access this file on 4.2?
Also, I could someone explain to me where the objects list is? I started following this tutorial
http://maybelost.com/2011/10/tutorial-storyboard-in-xcode-4-2-with-navigation-controller-and-tabbar-controller-part1/
as it seemed to be using Xcode 4.2, but when I get down to the storyboard section, it says
"Of course, we really want another tab on there so we can see the switching between the two – so lets drag in another Navigation Controller from the Utilities (objects) list and plonk it down somewhere. "
Except I cannot find this objects list? How do I open this objects list? What am I missing?
Sorry if these questions seem very basic, I am new to both Macs and iPhones. Android development seems a HELL of a lot easier from what I can see so far.
Thanks in advance for any help.
Also would be grateful if anyone could point in direction of any good up to date tutorials
I have a post on http://www.armandvanderwalt.co.za it will give you a nice understanding of how most stuff fits together, I don't use Interface Builder at all since it only makes the app bigger. Have a look at my blog post, still need to do styling, and add more posts but it is a nice beginner guide.
Most posts you are finding still use XCode 3 that's why you can't find certain things.
Also have a look at http://www.raywenderlich.com
What they are referring to as the object list, in XCode 4 it is found in the bottom right corner of Interface Builder. In XCode 4 Interface Builder is part of XCode and no longer an external application. Therefore when ever you open a XIB file Interface Builder also automatically opens