7 years, 2 months ago.

Problem with 128x64 Graphic LCD

Hi community!

First I have to say, that I'm new with mbed programming, so I tried my best to solve this Problem.

I've bough one of these Graphic-Displays from ebay: http://www.ebay.com/itm/KS0108-128x64-Graphic-LCD-Blue-Backlight-for-EasyPIC5-/130337989859?ssPageName=ADME:L:OC:AT:3160

Then I've connected the GLCD to the mbed like this:

RST = p13 DI = p12 RW = p14 E = p11 CS2 = p21 CS1 = p22 DB0 = p30 DB1 = p29 DB2 = p28 DB3 = p27 DB4 = p26 DB5 = p25 DB6 = p24 DB7 = p23

Since a couple of days now, I try to display text on this display. So my problem is that the display doesn't show any text or information. Is there anybody who does have the same Problem with one of these Displays. I don't know what it is, maybe the Initializing/Timing of the lib doesn't fit with the controller, maybe my wiring is wrong (I don't think so; I've rewired it three times, I've tested all my connections to the mbed with a multimeter(You know with that "Beep-Funtion")) Now I don't know what I can do to get this thing to work.

Additional Details: I've used the KS0108 library from Dimiter K (http://mbed.org/users/DimiterK/code/KS0108-driver/).

I would be very happy, if someone could help me :)

Thanks everyone, Chris

1 Answer

7 years, 2 months ago.

I don't think many people use those displays, then it is hard to guess what might be going wrong.

What did you do with the other pins? If you have your digital pins wired the same as in your code that shouldn't be an issue, but there are a bunch of other connections, where did you wire them to?

With a google I ended up here: http://embedded-lab.com/blog/?p=2398, it should be connected like that (but then to your mbed of course). Now I don't have any experience with this one, but I do know for the standard 16x2 character LCDs that an easy way to make an error is not connecting the contrast pin to a potmeter. Then it can happily show you text, but the contrast is completely wrong and you won't see anything.