LCD_AnyPin.pbp

[Pic_User]

Actually I see you have a pull-up on pin 1 and also have pin 7 tied low.

I don't see how pin 7 can be any problem for me but looking at the PCB I notice it doesn't have the pull-up on pin 1.

Existing (pre-programmed) 16F883's I have on my bench are working fine when inserted into this PCB so I have reservations thinking that's the problem at hand.

Thanks for your responses everyone.

See Darrel's Question...

In your code above, you have MCLRE enabled.

But in the schematic you don't have a pull-up on MCLR (Pin 1).
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Is the RW pin on the LCD connected to the PIC, or is it grounded?
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[PICn-It]

See Darrel's Question...

I'm sorry I don't understand your post, but I tried it with MCRLE_OFF and it makes no difference. I must have some other issues I'm yet unaware of. I have ordered a proper dev board so when that comes maybe I can get a handle on the problem.

I had set MCRLE_ON from trying to interpret the data sheet:

Page-212:
MCLRE: RE3/MCLR pin function select bit(4)
1 = RE3/MCLR pin function is MCLR
0 = RE3/MCLR pin function is digital input, MCLR internally tied to VDD

Page-215 (14.2.2)
An internal MCLR option is enabled by clearing the
MCLRE bit in the Configuration Word Register 1.

When MCLRE = 0, the Reset signal to the chip is generated
internally. When the MCLRE = 1, the RA3/MCLR pin
becomes an external Reset input. In this mode, the
RA3/MCLR pin has a weak pull-up to VDD.

These data sheets are a long read and at times I'm having trouble interpreting some of the pages.

[PICn-It]

Ok, making great progress.

I recieved my development board, plugged everyting in and coded up the demo example again ....and I'm getting text!
(woo-hoo!)

I'm getting:

#numbers Hello,
$hex From DT!

is this correct?

[Darrel Taylor]

Yessiree!
That's what you should get.
And the numbers should be counting.

Congratulations!
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[Peter.]

Darrel,

Top thanks to you for sharing such nifty code. Like your Bargraph code, I got it to work first time.
If by chance that you are still running this thread, would you perhaps let me know what I'm doing wrong when I hook all 6 LCD lines to the same Port? It works fine when I hook E and RS to separate Ports.
This is my first time with MPASM. I had to comment-out the config line, else it doesn't assemble.

Thanks again.
Respect for knowing all what you know about PICs.

[Darrel Taylor]

Hi Peter,

I'm not sure what the problem is, but I ran your program on a 16F877a with all the LCD pins on PORTB, and everything worked fine.
Although, with the pinout you are using ... you don't really need the LCD_AnyPin program (the data bus is on RB4-7).




For the config error, see this page ...
http://melabs.com/support/config_defaults.htm

[Peter.]

I'm gobsmacked.
Many thanks for taking the time to do that just on my account. Really appreciated.

Your photo has given me a good clue; I see that you are using B.2 and B.3. Up til now I'd been using B.0 and B.1 only.
It turns out that it only works from B.1 onwards (with both PBP *and* LCD_AnyPin). I thought it might be because of a hardware fault, but B.0 is fine with a temporary LED.
It's all rather strange because the PBP manual implies that any PortB pin should work.

Do you mind if I trouble you for one more question, pse?
Could you have a look at my CONFIG and perhaps let me know why MSC gives an error when I try to compile without the semicolon?

Thanks again to you for doing all that work on my account.