im trying to make v4l2loopback work on my desktop PC (no hardware camera) with mint 19.3, kernel 5.4.0-42-generic x86_64.
I followed the official instructions and compiled from git the v4l2loopback module and everything seem to run correctly, as no error prompted while running the instructions, but when i do ll /dev/v* there's no /dev/videoN entry.
I also tried with the flags exclusive_caps=1 and devices=2 but to no avail.
Any idea what i might be missing or doing wrong?
you need to load the module (e.g. using modprobe) before you can use it.
see also https://github.com/umlaeute/v4l2loopback#run
I have been trying to use the Arduino extension for VS Code in Ubuntu 18, but when I execute the initialize command, I get the error "Cannot find the Arduino IDE. Please specify the arduino.path in the user settings". So I wrote every path that comes out when executing the command "whereis arduino", I've also tried leaving the box empty (in theory that makes VS Code search for the IDE) and reinstalling both the Arduino IDE and VS Code several times, without any result. Does somebody knows a possible fix for this issue?
Download and extract the appropriate Arduino version according to your need from here, and install it using command sudo ./install. In my case, I have downloaded Arduino 1.8.6 Linux 64 Bit .
Goto Files -> Preferences -> Settings, Open Settings(JSON) as shown below.
Change arduino.path to the path location of extracted Arduino file. In my case it is /home/user/Downloads/arduino-1.8.6 and arduino.commandPath to arduino.
OR
For those who installed Arduino through snap platform refer this post.
Your Settings JSON file should look like this.
{
"arduino.path": "/home/user/Downloads/arduino-1.8.6",
"arduino.commandPath": "arduino",
}
Save and restart.
It's Done!!
Good Luck
P.S.:Add arduino.commandPath if not already exist and should point to Arduino executable present in the arduino.path.
Even when its on mac, someone can find this helpful as I had the same problem and found this thread. On MAC I have solved this one with arduino-cli and following:
install homebrew (if you have, proceed to step 2)
install arduino-cli with brew install arduino-cli
find where the arduino-cli is installed. Usually (on mac) it will be /opt/homebrew/bin/arduino-cli... Which means, if you run the command arduino-cli, it will execute this script... You can find the location with:
which arduino-cli (I have zsh, I am not aware if it will be the same for older bash, probably it will, I am not so skilled in this one, but you can try to use find instead of which. But which is working for me
lets assume you have the path, for me it was /opt/homebrew/bin/arduino-cli
proceed to VScode, go to settings (well, lets assume we will be working with the json settings
in my case, the input is following:
"arduino.useArduinoCli": true,
"arduino.path": "/opt/homebrew/bin/",
"arduino.commandPath": "arduino-cli"
Note, even when the path to arduino-cli is /opt/homebrew/bin/arduino-cli, we are removing the script name from the path... But we are adding this to the commandPath
I found that running whereis arduino or which arduino gave me /usr/local/bin/arduino. However, this didn't make Visual Studio Code happy. After some more digging, it turns out that that path is just a symlink to /opt/arduino-1.8.13. (Use ls -la /usr/local/bin/arduino to see where the symlink points to on your system.)
Also of note: be sure to give the path to the directory, not to the actual executable. For instance, in my case, the proper path was /opt/arduino-1.8.13 NOT /opt/arduino-1.8.13/arduino!
tl;dr
Use /opt/arduino-1.8.13, but be sure to update the version number to whatever is installed on your system.
This might not work for everyone, but the problem for me was using Visual Studio Code for flatpak. There was probably a better way to fix this, but the easiest way to do it (for me) was to install the binary from their website.
Go to "User Settings" > "Extensions" > "arduino.commandPath" > change it to "arduino_debug.exe"
In my case whereis arduino gave me /usr/bin/arduino and /usr/share/arduino, however putting either of them in the arduino.path didn't work.
Entering /usr/bin did the trick though. hope it helps!
(Ubuntu 20.04)
I use Windows and I solved it as follows.
The problem is because you are using the new version Arduino IDE 2.x.x and it has another way to code its sketches and more (I don't know how to say it, I'm a beginner in this) or you haven't activated to use Arduino Cli at least, so -- ->
Intall Arduino 1.8.x. You can donwload it here: Arduino Software
Open your vscode, go to Files>preferences>settings and find your Arduino extension under "Extensions". and put the standard path for Arduino 1.8.x like: C:\Program Files (x86)\Arduino (Remember this is where you installed the Arduino 1.8.x path) in "Arduino Path".
Next, you need to click on "Arduino: Use ArduinoCli" to link the Arduino extension to the correct version (Arduino Legacy is not allowed).
Arduino CLI option in vscode settings
Here's what fix my issue!
1st - Make sure you have the right path ("The path to the folder which contains the 'arduino.exe'", and not the path with the 'arduino.exe') copied to your Arduino Settings in VS Code.
2nd (The Actual Fix for me) - After installing the Arduino IDE and the VS Code extension RESTART you entire computer!! This somehow updates the Registry.
After which you can just Initialize your project, F1 - Arduino Initialize.
That's it enjoy and start up your Golden IoT project.
I am developing a kiosk type application using Yocto and a raspberry pi3. I have an hdmi touchscreen attached and have a USB keyboard attached for development only. My problem starts when I try to start GTK in one of my processes.
My project involves creating the kernel, has several processes running for various tasks, and will have a touchscreen GUI based on GTK+3 (using Glade).
My kernel is working and my processes are running and able to communicate with each other. But, now I'm having problems getting any kind of graphical output on the screen. Right now, all I have is console access as root.
When I start my 'display-mgr' process it tries to start up GTK. When it tries to 'gtk_init()', I get:
Gtk-WARNING ++: ...timeinfo...: cannot open display:
I've tried the usual 'export DISPLAY' stuff, but it looks like I don't even have the Xserver installed on the board.
I have:
DEPENDS = "libconfig pkgconfig-native gtk+ gtk+3 glib-2.0 libxml2 gnome-common glade"
in the recipe for my process. I also have: DISTRO_FEATURES_append = " x11" in my image recipe. Is there some package that I've missed?
I would recommend you start with core-image-sato from poky distro, and gradually replace the pieces. Alternatively, use core-image-weston, which would use that instead of x11.
I recently started using qemu and it's a great tool when you don't have the required hardware to run your firmware (currently using it for cortex-m3).
Now what I want to do is to do some test coverage with it. I tried using GNUC ARM Eclipse, and I've been successfull compiling and executing the code in qemu, but whenever I add the -fprofile-arcs -ftest-coverage flags (for the project and then for the desired file to run coverage) I am able to create the .gcno file, which means that after executing my code it will generate a .gcda file and then I should be able to see the coverage.
Thtat's where everything goes wrong. I was able to generate a .gcda file but whenever I try to open any of them, eclipse tells me that it wasn't able to open the file because it was null. I've tried replicating the procedure in another computer, but I haven't been successful creating the gcda file (probably different binaries).
At this point I don't really know how to proceed. Should I abandon ARM Eclipse and stick to makefiles (is it possibll to run gcov this way?) or am I missing something really small that is fixable?
PS: I using windows 7 64 bits, the latest versions available on the GNU ARM Eclipse website. Also the idea of doing it via makefiles just occurred to me (it was a stresfull day, it's really late) so I haven't tried it yet, I've only tried executing the code, but without coverage.
As far as I know, qemu is not able to generate DWARF information. But there is a project with the proposal of code coverage with qemu: Couverture Project
When you use qemu as a user space emulator (see also the qemu documentation) you actually can measure the code coverage as usual. In this mode qemu has the full access to the host file system.
For a CMake project you can simply use the CROSSCOMPILING_EMULATOR property of your test executable, e.g.:
if(CMAKE_CROSSCOMPILING)
set_target_properties(mytest
PROPERTIES
CROSSCOMPILING_EMULATOR "qemu-${CMAKE_SYSTEM_PROCESSOR};-L;$ENV{SDKTARGETSYSROOT}"
)
endif()
With this setting ctest will use qemu for running the test and will write the .gcda files to the usual location in your build directory.
I'm trying to build a rootfs for an blackfin target, However I can't figure out how I configure the kernel that buildroot produces. The first run through came up with menuconfig, but it's cached the .config since then and I can't see where to change it.
regards
santhosh babu
You need to run make linux-menuconfig to ask Buildroot to start the menuconfig interface of the Linux kernel.