/setoverscan

Adjust Raspberry Pi overscan interactively

Primary LanguageShell

setoverscan

Adjust Raspberry Pi overscan interactively

overscan

Get/set Raspberry Pi overscan values directly

  • Usage: overscan [<top> <bottom> <left> <right>] If an argument is an unsigned integer, the overscan of the corresponding edge gets set. If not, the overscan for that edge will not be changed. Without arguments, current overscan values are displayed. This example modifies top and right, and leaves bottom and left unchanged:
    • overscan 16 - - 24
  • Required: build-essential sudo[installing]

setoverscan

Adjust Raspberry Pi overscan interactively

  • Usage: sudo setoverscan
  • Required: coreutils(od dd head cat stty) grep sed ncurses-bin(tput clear) libraspberrypi-bin(vcgencmd) fbset whiptail overscan

Although I do most of my Raspberry Pi messing around on a headless Raspberry Pi via ssh my "gaming" Raspberry Pi is not always connected to the same monitor it was yesterday or will be tomorrow and because all my monitors are different makes and models I often found myself squinting at the monitor to count pixels so I could change the overscan values in /boot/config.txt and then rebooting to find that i'd miscounted and needed to make more changes to the overscan settings and repeating that until I got it just right.

As this was beginning to get annoying I asked the Raspberry Pi kernel guru Dom Cobley if he had an example of how to twiddle the overscan settings after booting and he sent me the code to do that. I've taken his program mailbox.c & made a few little changes to create overscan.c and have wrapped that in a simple bash shell script to make changes to the Raspberry Pi's overscan setting on the fly easy.

Because I need to use mknod to create a special file the script must be run by root or using sudo.

Use the included Makefile to build overscan and then run the set-overscan script. You currently use the arrow/cursor keys to change each setting in turn & the q key to move to the next overscan value to change. The script writes the final values to /boot/config.txt

Russell "ukscone" Davis 2013-03-10