128x64 graphic lcd with KS108 Controller

Erik006 · Guest

Hi folks,

I'm trying to get a GDM12864H lcd working, aquired from sparkfun electronics.

This lcd uses the KS108 controller, so I should be able to use the GLCD.c driver supplied with CSS, afaik. I'm using a PIC16F628A to with the lcd, setup with an internal oscillator (so I have enough pins). I did not have a 20K pot, so I used a 10K instead, which according to the datasheet, should be sufficient. Unfortunately, it does not seem to be working for me.

Any thoughts on this?

Erik006

PCM programmer · Joined: 06 Sep 2003 Posts: 21708

Post your #define statements for the connections to the Graphic LCD.

In GLCD.c, the Reset pin on the LCd is connected to pin C0 on the PIC.
But the 16F628A doesn't have a Port C, so you must have connected it
to another pin. That's why I'm asking for a list of your connections
between the PIC and the LCD.

Erik006 · Guest

pin a0 - GLCD_CS1
pin a1 - GLCD_CS2
pin a2 - GLCD_DI
pin a3 - reset (also tried this with pin a6)
pin a4 - GLCD_RW
pin a5 - GLCD_enable

port b -> data bus.

I have the following method calls in my main function:

PCM programmer · Joined: 06 Sep 2003 Posts: 21708

Erik006 · Guest

Hi,

Thanks for your reply. I changed my circuit using your suggested changes, and on the upside, the lcd functions consistently. However, when I try to display a line, or a pixel, instead of a single dot appearing per x location, about 5 appear. This is consistent for a line, a pixel, a square and a bar.

Any idea what this could be?

Erik006

PCM programmer · Joined: 06 Sep 2003 Posts: 21708

Post your compiler version. This will be a number such as 3.249, or
4.013, or 4.037, etc. You can find it at the top of the .LST file, which
will be in your project directory.

Erik0062 · Guest

Hi,

The compiler version is 4.013.

Erik

PCM programmer · Joined: 06 Sep 2003 Posts: 21708

That version is so early in the vs. 4.xxx series that it could be the
problem. If possible, test your program with vs. 3.249.

If that doesn't help, then Mark recommends some modifications to the
driver, to allow checking the busy flag.
http://www.ccsinfo.com/forum/viewtopic.php?t=29163

Erik006 · Guest

hi,

Although I haven't been able to get it working properly yet, because I don't have access to the older compiler. I will try and implement the changes suggested in the link you gave me. I'm a bit confused as to the actual workings of the changes, but I hope I can get a grip on that soon.

PCM Programmer, you have been very helpful in your quick, courteous and concise responses. Thank you VERY much.

Erik006