Brightpad lets you (fully) control the brightness of your PSP’s screen.

Changes:

Replaced ‘minimal brightness’ by ‘default brightness’ in the configuration file
Removed ‘show remaining’ and replaced it by ‘button mask time’, where you put the button to hide or show the battery’s remaining online time.
Added a bar where the current brightness is shown while changing, you could say it’s the beginning of a GUI :p
As usual, in-game you’ll first have to press ‘primary button mask’ and then ‘button mask time’ to hide or show the battery’s remaining time.

http://forums.qj.net/psp-development-forum/167899-new-file-added-brightpad-v5.html