Cross compile Qt 5.3 on Olinuxino a20, inverted x-axis problem
I have an Olinuxino-Micro with the official Olimex Debian image (release 7). Mali libraries installed. I have cross compiled qt 5.3.2 on my host. I can build and deploy apps from my host with no problems and qt apps works well on my board. I'm using the 10' touchscreen by olimex.
I use eglfs platform (for fullscreen)
I run apps with " -plugin evdevtouch:/dev/input/event0" (without this parameter the touch doesn't work).
Tslib is installed and working (i can run ts_calibrate with no problems) (btw wt5.3 uses evdev by default).
Now the problem is that the x-axis is inverted, if the app has a button on the left i have to press on the right of the screen.
I googled this problem and i found it's an evdev problem but i can't figure out how to solve it.
I tried adding the option invertx but nothing changed.
I tried also with -plugin Tslib but it doesn't work (because there is no tslib plugin in qt plugins directory)
Can someone help me?
Thanks in advance
PS. Sorry for my english
So...anyone can help me?
If there is no solution for "fix" evdev, how can i compile Qt5.3 with tslib plugin?
There are environment variables you can use to rotate the touch coordinates:
On some touch screens the coordinates will need to be rotated. This can be enabled by setting QT_QPA_EVDEV_TOUCHSCREEN_PARAMETERS to rotate=180.
But I haven't seen anyting for mirror image.
Check out the other options at
Hi, thank you for your answer. I've already tried that variable with rotate=180 but it only blocks the touchscreen. So, no touches detected.
Now i'm trying to follow this discussion
to add tslib support, but i don't know if it's the right way.
I have the same problem as you do. It is really anoying and the answer doesnt exists. I spend couple of days of trying to fix this. I can calibrate touchscreen on X11 using xinput, but not for eglfs platform. Only one nasty solution I found and using is to rotate the application using "transformation : Rotation", than touches works fine. But the solution is not good for me, because I would like to rotate display using Linux Kernel command to be the way I want and then just swap axis for touch in application...
If you find the solution, please let me know.
The only solution i've found is to disable evdev and use Tslib.
Qt5 and > does not build Tslib plugin by default, you have to use -Tslib option during the configure command. After that you have to run an application using "-plugin Tslib". You have also to disable evdev setting QT_QPA_EGLFS_DISABLE_INPUT environment variable to 1.
This is the way i solved.
Thanks for advice, I was also dealing with tslib, but there I was unable to run ts_calibrate or any ts_ lib. I have set that up correctly, I was working with Tslib before with couple of different ARM boards -correctly exported all variables, uncommented module_input in configuration, also crosscompiled tslib plugin to QT ... I have even tried to compile couple of different versions of tslib without success... Strange was, that ts_calibrate was running and just did not receiving any touch event, but when I try events in evtest or use evdevtouch, than it works ... I will give a try to tslib couple of other hours...
Such a huge framework and they do not create working variable for swapping axis?
Ye i couldn't find another solution.
Do you have "mirrored x" or "rotated x"? i mean, if you have a MouseArea on the bottom left corner where do you have to touch? bottom right? or top right? i'm asking this because i read that many people have rotated x problem and they only needed to set an evdev environment variable to solve that problem.
The only thing about Tslib that i can say is that installing the offical Debian image by Olimex on my board, Tslib is already installed and working (both ts_calibrate and ts_test work good).
If your ts_calibrate was running but not receiving touch events maybe you set up the wrong input device?
Have you ever check in "dev/input" what is your touchscreen name? just make cat /dev/input/eventX , where X is a number. Mine is 0.
I'm sorry if i can't give you a solution, i've also lost so much time on this problem because no one could give me a right tip.
Yes, tell me about that.... I spent around 5 full days with evdevtouch and before about a month with tslib. I was even trying to rewrite Qt libraries and with that I was able to recalibrate and maybe I will do some patch for it in future when I find a time doing that, the code for qevdevtouch is in /qtbase/src/platformsupport/qevdevtouch.cpp. There is even the function which should get rotated argument from exported environment, so far I was looking into the code, I don't see there a problem... But it will be horrible to deal with it, because all the time I would recombile evdevtouch plugin, I have to put it on the board to test the results...
I am having probably rotated x,y? - for the button on upper right corner, I have to touch down-right. Button on the left upper corner I cannot touch - maybe I am out of coordinates, because they are swapped. I am also having a listview in app and for scrolling down, I have to slide on a screen from right to left, so somehow axis seems to be swaped (y is insted of x) ...
When I export QT_QPA_EVDEV_TOUCHSCREEN_PARAMETERS="rotate=180", than it simply doesnt receive any signals from touch...
Yes, regarding tslib, I am sure, that I have exported right input - when I do "cat" for that exported device, I am receiving touch inputs...
I appreciate your advice, I will go to fight with this issue more, but I am really loosing a patience now... :(. Someone from QT should look on this issue, because I thing it is pretty serious...
Ye that's really an annoying problem, i know your feeling.
When i was using that rotate parameter my screen didn't receive any signal too. That was my last try with evdev and i switched to Tslib. I'm only lucky Tslib was already installed on my Debian image.
Anyway, imho, i think it's easier to build and install Tslib rather than try to configure evdev.
In your place i wold try to re-do all from beginning. I mean, i'm using an Olinuxino board with an SD card for boot, i would re-do my SD card, install the OS and try to build and configure tslib right on the board. I don't think it's a long process so i don't think you need to cross compile tslib. Just after that cross compile Qt with the -Tslib option.
I'm just trying to give some advices but i'm not so expert with these things.
Yataaaaaaaaaaaaaaaaaaaaaaaaaaa I have the solution!!! When I was looking now to the code of qevdevtouch, I figure out, that there is a bug, it takes rotate parameter directly from the line, so when you start you application like that : " ./myApp -platform eglfs -plugin evdevtouch:/dev/input/event1:rotate=90 - or whatever your rotation is, than it works!! I just tested it.
In a code there is split for ":" and checks for other argument parameters instead of using environment par.
I'm happy you solved your problem!!! ;)