Darrel's SPWM and LCDOUT

[Darrel Taylor]

R-M-W is "Read-Modify-Write". It's the way PIC chips set an individual pin by reading the entire port, changing the 1 bit for the desired pin, then writing the whole port again. It can cause problems from time to time, but that is not the problem here. If the LCD and SPWM pins were on the same port it could have been. But I hadn't seen any code at the time, so I was guessing.

And to keep from guessing again, could you post the whole program?

I've run LCD's with SPWM before, so I don't think there's a common cause that I could point to. Hoping there's something else going on.
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[mister_e]

Maybe just a LCD clear... or PSU noise.. who know?

LVP_NOT set to OFF.. huh... how bad things could go with it...

[Darrel Taylor]

What surprises me is that the entire line changes to a different character.

If it was a timing problem from the interrupts, I'd think it would be more Random.
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[mister_e]

Looks like the PIC itself reset here and there... i still bet on some kind of noise... or UFO interferences... stack under/overflow?

Fishing in the dark..

[DaveC3]

Don't the DEFINES have to be in CAPs?

[mister_e]

dEFINE, define or else variant will work, what's important it's on the right of it.

[Darrel Taylor]

I googled "Optrex DMC20481" and found a post on another forum suggesting that the LCD_COMMANDUS of 2000 was too low for that display. He said that 3000 worked for him.

I pulled up the datasheet, and there doesn't seem to be any mention of the actual delays required. I guess if they're that bad, I wouldn't want to publish them either.

Something to try.
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