For example:. Note that on devices with more than 1GB of memory the arm parameter will always return 1GB minus the gpu memory value, since the GPU firmware is only aware of the first 1GB of memory. Those highlighted currently require a paid for licence see the this config. Note that because the H. Displays the current HDMI settings timings. See Video Config for details of the values returned.
Show current display power state, or set the display power state. If no parameter is set, this will display the current power state. The final parameter is an optional display ID, as returned by tvservice -l or from the table below, which allows a specific display to be turned on or off. Note that for the 7" Raspberry Pi Touch Display this simply turns the backlight on and off. The touch functionality continues to operate as normal. It needs to be run as root.
This application is mostly of use to Raspberry Pi engineers, although there are some commands that general users may find useful. Without any further parameters, lists the current status of the relocatable allocator.
Use sudo vcdbg reloc small to list small allocations as well. Use the subcommand sudo vcdbg reloc stats to list statistics for the relocatable allocator. Use sudo vcdbg hist gnuplot to dump task history in gnuplot format to task. Python syntax is clean, with an emphasis on readability, and uses standard English keywords. The easiest introduction to Python is through Thonny , a Python 3 development environment. You can open Thonny from the Desktop or applications menu. In the Thonny application, this is called the Shell window.
Thonny also has syntax highlighting built in and some support for autocompletion. However, Python does not use curly braces but instead requires indentation for nesting. For example a for loop in Python:. The indentation is necessary here. A second line indented would be a part of the loop, and a second line not indented would be outside of the loop.
Note that data types were not specified with these variables, as types are inferred, and can be changed later. Comments are ignored in the program but there for you to leave notes, and are denoted by the hash symbol. Multi-line comments use triple quotes like so:.
Python also has lists called arrays in some languages which are collections of data of any type:. Lists are denoted by the use of square brackets [] and each item is separated by a comma.
Some data types are iterable, which means you can loop over the values they contain. For example a list:. Note I used the word number to denote each item. It makes it easier to understand when reading. The integer data type is not iterable and trying to iterate over it will produce an error.
To get the numbers 1 to 5 inclusive use range 1, 6. This is an empty file, not a Python prompt. You can write a Python file in a standard editor , and run it as a Python script from the command line. Just navigate to the directory the file is saved in use cd and ls for guidance and run with python3 , e. This shell is a prompt ready for Python commands to be entered.
You can use this in the same way as Thonny, but it does not have syntax highlighting or autocompletion. IPython is an interactive Python shell with syntax highlighting, autocompletion, pretty printing, built-in documentation, and more.
IPython is not installed by default. Install with:. Then run with ipython from the command line. It works like the standard python3 , but has more features. Try typing len? Some Python packages can be found in the Raspberry Pi OS archives, and can be installed using apt, for example:. This is a preferable method of installing, as it means that the modules you install can be kept up to date easily with the usual sudo apt update and sudo apt full-upgrade commands.
Not all Python packages are available in the Raspberry Pi OS archives, and those that are can sometimes be out of date. Raspberry Pi OS is pre-configured to use piwheels for pip. Read more about the piwheels project at www. Any of the GPIO pins can be designated in software as an input or output pin and used for a wide range of purposes. Two 5V pins and two 3V3 pins are present on the board, as well as a number of ground pins 0V , which are unconfigurable.
The remaining pins are all general purpose 3V3 pins, meaning outputs are set to 3V3 and inputs are 3V3-tolerant. This is made easier with the use of internal pull-up or pull-down resistors. As well as simple input and output devices, the GPIO pins can be used with a variety of alternative functions, some are available on all pins, others on specific pins.
A handy reference can be accessed on the Raspberry Pi by opening a terminal window and running the command pinout. In order to use the GPIO ports your user must be a member of the gpio group. The pi user is a member by default, other users need to be added manually. The library is comprehensively documented at gpiozero. LED methods include on , off , toggle , and blink.
Introduction Edit this on GitHub. Copy to Clipboard. Running Out of Space When running sudo apt full-upgrade , it will show how much data will be downloaded and how much space it will take up on the SD card. Searching for Software You can search the archives for a package with a given keyword with apt-cache search :.
SL stands for Steam Locomotive. Installing this package makes tree available for the user. The user is prompted to confirm the removal. Again, the -y flag will auto-confirm. Using rpi-update rpi-update is a command line application that will update your Raspberry Pi OS kernel and VideoCore firmware to the latest pre-release versions.
What it does rpi-update will download the latest pre-release version of the linux kernel, its matching modules, device tree files, along with the latest versions of the VideoCore firmware. Running rpi-update If you are sure that you need to use rpi-update , it is advisable to take a backup of your current system first as running rpi-update could result in a non-booting system.
How to get back to safety If you have done an rpi-update and things are not working as you wish, if your Raspberry Pi is still bootable you can return to the stable release using:. You will need to reboot your Raspberry Pi for these changes to take effect. Consumer Electronics Control, or CEC [4] , is the official standard for control functions that allow the user to command and control more than one entertainment electronics device through just one control.
Most of the newer television sets support CEC. Depending on the brand, CEC is known under various names. The LibCEC software [5] then captures this input and forwards it to the media player.
Using either a mouse or the arrow keys on the keyboard, navigate from the main menu to the menu options: Pictures , Videos , Music , Programs , System. The Down arrow key takes you into the submenus, and the Up arrow key takes you back. You can return to the main menu at any time by pressing the Esc key.
Once in the menus, navigate step by step backwards using the Backspace key. The C key takes you to the context menus, which you can open with a right mouse click. Table 1 describes some important XBMC settings. You will find all these menu options under System Settings. Note that the news ticker that sometimes appears in the main menu is not absolutely necessary and, in fact, slows down the menu build perceptibly.
Language, region, and character set settings. If you have set the language incorrectly in the set-up assistant, you can correct the problem here. XBMC generates preview images from new videos when the database is updated. This process takes too much time on a Raspberry Pi. A lower resolution increases the build speed of the menus. The resolution for videos is not affected. This function corrects alignment if the the Raspberry Pi image does not fit cleanly on the TV screen.
This menu offers numerous options for optimizing the interaction. Both XBMC distributions have a configuration tool. Raspbmc integrates the Raspbmc Settings into the Programs menu. Be sure to set up network access. The Raspbmc tool Figure 1 offers the added option of connecting other hardware like external sound cards, webcams, and infrared receivers.
Note: The apt full-upgrade and apt-get distro-update command perform the same function. This command keeps your current release up-to-date. If you want to free up some space on your Raspberry Pi, run the clean command to remove the downloaded. To update Raspbian from an older version for example, Stretch to the latest Buster, at the time of writing , you need to edit a few files.
Locate the sources. Use the editor of your choice. We will use vi:. The upgrade takes some time. Confirm with yes when prompted. Use the space bar to scroll if the installation shows a page of information and press q to resume the upgrade.
By following this tutorial, you learned how to keep your Raspberry Pi updated. This guide also showed you how to upgrade from Raspbian Stretch to Raspbian Buster.
Make sure to update Raspberry Pi frequently to avoid security and performance issues.
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