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rosco
Joined: 14 Jul 2004 Posts: 3 Location: UK
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Posted: Wed Jul 14, 2004 11:23 am Post subject: LCD connections |
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Hi,
I have a PCB with the LCD R/W line connected to a Port pin. It is used in 4bit mode. Is there a way to reset this Port pin (R/W = 0) before attempting to perform the Config Lcd function so that it will work ok? It works fine with the R/W line hardwired to 0v.
I need to do this to avoid cutting tracks.
Regards Ross |
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Vilko
Joined: 25 May 2004 Posts: 190 Location: Ljubljana, Slovenia
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Posted: Thu Jul 15, 2004 7:18 am Post subject: How about |
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Hi,
Well how about
portpin = 0
if it does not work, then simply hard connect R/W to GND, it will not harm portpin at all. (I think)
Vilko |
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rosco
Joined: 14 Jul 2004 Posts: 3 Location: UK
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Posted: Thu Jul 15, 2004 10:07 am Post subject: |
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Thanks Vilko
I have allready tried that, both as a BASIC and assembler command but neither work.
I think the compiler must perform the "Config Lcd" first and then sort the rest of the code.
If I connect my scope to the LCD E & R/W pins I can see the E line active high pulses before the R/W line is driven low, allthough the instruction to reset the portpin is placed before the "Config Lcd".
You are right though, it is probably ok to tie the pin to ground, especially if I reset it in my program. It is only like using it as an input.
Ross |
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albertsm
Joined: 09 Apr 2004 Posts: 5913 Location: Holland
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Posted: Sun Jul 18, 2004 11:53 pm Post subject: |
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Set the pin to 0, and use LCDINIT command to re-init the display. _________________ Mark |
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rosco
Joined: 14 Jul 2004 Posts: 3 Location: UK
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Posted: Mon Jul 19, 2004 9:12 am Post subject: |
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Thank you Mark, I knew I had seen a way to do it. Just could not remember where!
As usual a case of RTFM. (Read The Flipping Manual).
Regards Ross |
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