Garbage pixels on GLCD top row

[rrsquez]

Hello. I have a problem that is probably related to interrupts and the GLCD. I didn't see this problem before when I wasn't using interrupts. This may be a clue.

Attached is my code, and two pictures of my GLCD in operation. I have added some arrows and notes to demonstrate the problems. Please ignore the problem where time and date where written to an incorrect location. I think I fixed that problem, or it's related to the current problem which is why I have presented it.

At the top row of the GLCD you will see some garbage pixels. I do not know what is causing this. When I first reset the board these pixels are cleared. Upon letting the unit run, these garbage pixels will just suddenly appear all at once (not building up). I have to let the unit run for a few minutes for they show up. This time period varies (50 seconds to a few minutes).

I have reduced my code to the bare bone essentials. My interrupt service is simple and only calls upon the hardware devices it is reading and displaying. I tried eliminating all extraneous code to hunt down the offending code. Now it is simple, but I cannot determine the source of this problem.

Please be advised that I think the offending function is called Gl_putmsg();. This is the function that writes text to the LCD. I only print a graphic to the screen once during startup. All update to the LCD are done through Gl_putmsg().

Would someone please look at my code and tell me if they can spot something wrong?

Thank you, Richard V