View Full Version : Turn off LCD backlight

03-14-11, 05:49 AM
How can I turn off the LCD backlight? I would prefer one or more of the following options:

Permanent LCD on/off toggle function
Activate backlight on (LCD) activity
Turn off backlight after x time of (LCD) inactivity.

03-14-11, 01:53 PM
In general, the only way I have found to control the LCD is through the astmanproxy daemon written in C code. I have customize this code on a few occasions and from this I will share what I have found. astmanproxy is the code that displays the ports, handles the button toggles, etc. And this is also the place where I think code modification would be necessary.

'package/astmanproxy/astmanproxy.mk' in PADS shows where the source code for this package can be obtained. The basic hiearchy of code in this astmanproxy package is following: astmanproxy -> pika_lcd_sample -> pikalcd. This pikalcd layer uses a more defined API prefixed with 'PK_LCD_' provided by a separate library. I found some old documentation for this API in the following document link under Appendix A. http://outgoingftp.pikatech.com/appliance/2.1/docs/PADS_2.1_User_Guide.pdf

In this API there is a PK_LCD_SetConfig function which sets the PK_LCD_TLCDConfig structure. In this structure there is a 'brightness' field which represents a percentage of brightness. Using this function I think one could selectively pick when to light up or darken the LCD in the astmanproxy code. Hope this general outline is of help.