Issues with backlight (GLK1232-25-SM)

lugiber · Post by **lugiber** » Sat Feb 12, 2005 11:43 am

I have now attached the GLK1232-25-SM to my computer and it works great!
I have trouble with the backlight though. Sometimes the backlight turns off when i restart the computer and i can't start it manually again. I have tried starting it with both lcdc and mogd but nothing works.

Anyone have a clue?

/Peter

Tom · Post by **Tom** » Mon Feb 14, 2005 10:52 am

Hi Peter,

Thank you for posting at the forums.

First off, when your backlight goes off, do you have other communications working still like the contrast or the ability to send text?

lugiber · Post by **lugiber** » Mon Feb 14, 2005 2:20 pm

Thanks for replying.
Yes everything works except turning the backlight on and off. The only solution i have found that solves this problem is to turn the computer off for ten minutes or so. When i power up the computer again the backlight is working again.

While i have your attention i would like to ask a question about the keypad. Am i right that the only thing you need to do in order to get a working keypad is to connect switches that connects to the "column pins" to the "row pins". There are no diodes or resistors required right?

Thanks for helping me out!

/Peter

Tom · Post by **Tom** » Mon Feb 14, 2005 2:27 pm

That is a strange problem with the backlight. Can you try it on another computer, so we can eliminate any possibility it is the computer that is causing the strange backlight behaviour?

You won't need any extra resistors or diodes to get the keypad to work. You can just connect the switch to a row and a column. The pic already has weak pullup resistors.

Best Regards,