Hot answers tagged

31

The driver for the screen provides an interface through /sys/. To turn the screen on you can use the command: echo 0 > /sys/class/backlight/rpi_backlight/bl_power and to turn it off: echo 1 > /sys/class/backlight/rpi_backlight/bl_power the brightness can be adjusted using: echo n > /sys/class/backlight/rpi_backlight/brightness where n is some ...


28

The other solutions here did not work for me (fresh Raspbian, boot to GUI). Instead, this worked: Open up /etc/lightdm/lightdm.conf using your favorite text editor (I prefer nano). Look for the line #xserver-command=X. Change it to xserver-command=X -s 0 dpms It should be at line 87 if things don't change. Save and reboot. Source


25

Presuming you are logged in as the same user that's running the X display, this is fairly easy. First you need to know the display identifier; if there is only one running instance, it is probably :0. To check, use who. You'll see output including stuff like this: goldilocks pts/5 2015-02-16 07:18 (:1) goldilocks pts/6 2015-02-16 07:18 (...


21

There is a few things you can try: 1) Edit /etc/rc.local and add the following lines above exit 0: # Disable HDMI /usr/bin/tvservice -o this will turn off the display, but only somewhere during the boot sequence 2) add hdmi_blanking setting to your /boot/config.txt I found the follwing settings here: hdmi_blanking=0: HDMI Output will be blank when DPMS ...


18

I simply added a nocursor option as follows in the file (/etc/lightdm/lightdm.conf) xserver-command = X -nocursor and it worked as it should. No cursor is displayed whatsoever. You can still put your finger on the touch screen and do what you normally do with your mouse pointer; Clicking and Dragging.


17

I have developed lazycast that is designed to work on Raspberry Pi 3. lazycast follows (most of) the wifi display specification (commercially known as Miracast) and uses wifi p2p (commercially known as WiFi Direct) to set up a connection. I have tested it with Windows 8.1 and 10 sources. It requires no modification (using the built-in wifi) to the hardware ...


16

As it turns out several overlays can be loaded by adding multiple dtoverlay variables: In this case: dtoverlay=4dpi-3x dtoverlay=w1-gpio


15

That cable is most likely a DisplayPort-to-HDMI cable not a HDMI-to-DisplayPort cable (mind the direction). While there are DP ports able to support HMDI signals (DisplayPort Dual-mode) HDMI does not support DP directly. Since HDMI data transmission is very different from DP there will be no simple (passive) cable that just re-routes some signal lines on the ...


14

I think @Jivings answer may be better, but I have it in my notes to do this: Install apt-get install x11-xserver-utils Edit /etc/xdg/lxsession/LXDE/autostart Append these lines: @xset s noblank @xset s off @xset -dpms Possibly also comment out the line that says @xscreensaver -no-splash, so the complete file should look something like this: @lxpanel --...


11

I've made a Python package for this: github.com/linusg/rpi-backlight. Now you don't need to implement this yourself anymore. (GIF is outdated because API was changed quite a bit in v2, sorry... Below example is correct 🙂) Works basically like the above, example: >>> from rpi_backlight import Backlight >>> >>> backlight = ...


10

To prevent the screen from going blank try adding consoleblank=0 to the end of the first line of /boot/cmdline.txt Source


10

To access an UNIX server from a Windows client, my preferred combination is PuTTY + Xming. Xming is easy to install, lightweight, fast, stable, and works pretty well overall. The procedure (also explained here): Enable the X11 forwarding option in PuTTY (Configuration > Connection > SSH > X11 > Enable X11 forwarding) Start Xming on your Windows machine: ......


9

Following answer from reddit was helpful: The yellow-white-red ports are for composite video (yellow) and stereo audio (red and white). These plugs typically use RCA connectors. The Pi has an RCA composite video out, and a 3.5mm audio out jack (the same thing you'd find on a smartphone, iPod etc, i.e. a "headphone jack") So, to connect the Pi to your TV, ...


9

As an addition to Goldilocks' answer, for epiphany you can set the display using the --display option: epiphany --display=:0 http://example.com &


8

The Raspberry Pi Foundation claims unambiguously that a VGA adapter on the GPIO header "means you can use it as a secondary monitor alongside HDMI" (from here). You should certainly be able to do that via USB; for evidence of the the pi running multi-headed, see comments below. The exception, of course, is trying to use the HDMI and the RCA video ...


8

In your /boot/config.txt file try changing disable_overscan=1 and see what that does for the borders. If that does not help, leave disable_overscan=1 and then try changing these values as well. overscan_left=20 overscan_right=20 Overscan_top=20 Overscan_bottom=20 It will take some trial and error to find the correct values because the correct values are ...


7

There are a few options. In increasing order of difficulty. You can buy USB touch screen from somewhere like elo touch, but be prepared to spend ~$400 for a resistive 15" screen. You could buy a touch overlay kit from ebay and apply it to an ordinary hdmi monitor. Finally, you could buy and lvds to hdmi convertor from somewhere like http://www.njytouch....


7

Wand has a display module/method. In the terminal $ python -m wand.display wandtests/assets/mona-lisa.jpg In a Python script import wand with Image(blob=file_data) as image: wand.display.display(IMAGE)


7

I'm not sure this will help, but had this similar problem on my Raspberry (old 1 Model B) also yesterday. I had not noticed it before because I only recently started using it with X and a monitor. Every time I scrolled in a browser window or even an lxterminal the screen would go blank for 2 seconds seemingly randomly. Changing resolution or tweaking with ...


7

Indeed, it was a problem with the drivers. I switched to use Raspbian and then I installed the drivers, like explained here. Dowloaded the driver Extracted the files (tar xvf LCD-show.tar.gz) cd LCD-show/ sudo ./LCD35-show (this depends on the display size, mine is 3.5") In my case it didn't reboot automatically, but it displayed some messages regarding ...


7

The problem is that your keyboard is using the default UK mapping. Assuming you are using Raspbian you can use the raspi-config utility to change the keyboard layout. From the command line type sudo raspi-config. From the menu: choose option 5 International Options Then I3 Change Keyboard Layout Next choose your keyboard model (there are generic choices ...


7

Most laptop hdmi ports are output not input. They are designed to connect a laptop to a monitor. There are a few that have hdmi input. You could use VNC Viewer on your laptop to view the Pi screen (by enabling VNC in Pi Configuration) over wifi/network.


6

If you know you won't be using the composite output, you can set up the pi to always use the hdmi output, even when no device has been detected. That way it will pick up the screen when it's attached, even if done at a later stage. In your config.txt add/change the following line: hdmi_force_hotplug=1 For more (screen and other) settings, see http://...


6

Composite output defaults to NTSC. If you got a PAL tv it wil display monochrome. Try changing your config.txt and uncomment the line sdtv_mode=2: # uncomment for composite PAL sdtv_mode=2


6

You have to define which display to use first : export DISPLAY=:0 xset s reset Hope this helps


6

If you're using an X11 Desktop Environment such as LXDE, then you can accomplish this using the basic logic shown in this article. Here's what I came up with to switch displaying two images waiting 30 seconds between each switch. You should be able to insert your logic for switching the images based on what you read from your RFID sensor. displayImages.py ...


5

HP's L2105tm is a 21.5 inch 1080x1920 touch monitor that works flawlessly with the Raspberry Pi. It isn't resistive, so the response is slower than what you will be used to if you have used a resistive touch screen. But if you have not used a resistive touch screen, you'd never call it "slow". I bought a hand full of this model a few years ago for right at $...


5

You have edited the wrong file; disable_splash=1 should be in /boot/config.txt.


5

In /boot/config.txt, uncomment the line with config_hdmi_boost and change its value to =6. The suggested value of 4 was still too low for a Samsung 205BW monitor connected to a Raspberry Pi 3.


5

What you want isn't possible. Laptop/netbooks aren't configured to accept video directly from a port to the screen. The hardware simply doesn't support it. Any solution that could make this work requires software, and would either use a network connection, or maybe USB. Since you can't start the netbook, this seems like a moot direction.


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