See also the list of Known Issues.
I have problems deploying/launching the application in Qt Creator
Check that the device is properly connected to the development host via USB or Ethernet (depending on the device). See Connectivity Issues.
If using the emulator, see Installing VirtualBox.
I have problems deploying/launching a Qt or Qt Quick example application
Because of a technical peculiarity in
qmake, it is not possible to get correct deployment setup for any application that is placed inside a Qt source code tree.
The workaround is to copy the example sources to a location outside the Qt source tree, and open this copy of the example application instead.
I have problems launching or running applications on hardware after updating the SDK
Remember to repeat the process of updating also your device with the latest version of Boot to Qt. See Installing Boot to Qt on Target Devices.
Booting BD-SL-i.MX6 stops with '6x_bootscript not found' error
Check the U-Boot version number. It should start with either
2013. If it is
2009.xx, an upgrade of the bootloader is required. For more information, see:
How do I get HDMI output working properly on BeagleBone Black?
Depending on the HDMI monitor, the cable, and the build variant of the BeagleBone Black device, it may not be able to drive an HDMI display in a stable way; the image may disappear or stutter. These issues are not caused by the Boot to Qt stack.
More details and possible solutions can be found here.
The following command shows the system log:
Note: When terminating an application from Qt Creator, you may see the message Terminating application. Error running process: Process crashed. This is normal and does not indicate a problem in your code; a SIGTERM signal is sent to the application, and Qt interprets it as a crash.
Mouse or touch input does not work
Note: On Embedded Linux hotplugging is usually supported for mouse and keyboard devices.
Application stops with 'EGLFS: OpenGL windows cannot be mixed with others.'
OpenGL and Qt Quick 2 applications can only have one fullscreen window existing at a time. Trying to create another OpenGL window, or trying to mix an OpenGL window with a raster one will display the above message and abort the application.
Note: For raster windows (software rendered content based on QWidget or QPainter), there is no such limitation.
I cannot edit the contents of appcontroller.conf on the device
The file system where this file is located may be mounted as read-only.
How to enable C++11 features
To enable C++11 features in the compiler, add CONFIG += c++11 to the .pro file.
I cannot connect to my hardware device via USB
Additionally on Windows, you may need to install or update the Android Device driver. You can check whether a driver is already installed when a device is attached via the Device Manager. If you haven't installed any driver there should be an USB Function Filesystem under Other devices. If this is the case you have to install the USB driver by the following steps:
- Open Other devices > USB Function Filesystem).
- Switch to the Driver tab and click Update Driver.
- Do not let windows search automatically for an updated driver, but select "Browse My Computer for driver software".
- Select "Let me pick from a list of device drivers on my computer".
- Open "Have Disk..."
- Install the driver that is located at <Android-SDK-Tools-install-dir>\extras\google\usb_driver\android_winusb.inf
If you already have an Android ADB Interface under Android Device you may need to update the driver. This can be achieved by running the previous steps on the Android Device > Android ADB Interface.
adb fails with "error: more than one device and emulator"
You have to specify which device you want
adb to talk to, using adb's
-s <serial-number> option. Use the following command to find to see the serial number of the connected devices:
The emulator cannot connect to the Internet
By default, the VirtualBox is configured to use a host-only network, so external connections do not work in the emulator.
You may be able to enable Internet connectivity with another virtual network adapter in NAT mode by adapting these instructions.
The emulator is stuck in Waiting for display data or fails to start properly
Check the output of the following command:
If the emulator (192.168.56.101) is not listed there, try connecting to it:
<INSTALL_DIR>/Tools/b2qt/adb connect 192.168.56.101
If the emulator is already listed, try disconnecting it:
<INSTALL_DIR>/Tools/b2qt/adb disconnect 192.168.56.101
And then close the emulator and retry.
What are the user and password to access my embedded Linux device?
Embedded Linux devices can be accessed using user
root and an empty password.
Available under certain Qt licenses.
Find out more.