I can not figure out an LCD issue

[mackrackit]

When you say resonator I think of a three pin thing with built in caps, HS works for that.
If you are using a crystal then you may want to check the caps.

Forget the LCD for a bit and figure out the timing problem by blinking an LED once per second.

[lilimike]

Thanks Malc-C for the reply but I am not exactly trying to make it work...
Well yes I am trying to make it work but first I am trying to understand what is happening and what is my issue.

Mackrackit,
I am using a resonator (3 pins with caps incorporated) and double checked the datasheet and it does suggest _XT_OSC for a 4 MHz resonator.

I followed your suggestion and I put a LED with puse 1000 and also it is taking 2 secs to blink. Now, I set DEFINE OSC 4 instead of 8 which brought down to 1 sec as I expected so I know that if i am using a 4 MHz crystal, I should be having DEFINE OSC 4. I could be wrong but I think this part is clear to me.

So my questions are changing a bit and now I end up with:

1 - Why does LCD_AnyPin only works with DEFINE OSC 8 although I have a 4 MHz crystal ?

2 - Why the standard way for LCD is not working whisle LCD_AnyPin did even at 8 ?

When I find out, I will never forget it!

Mike

[lilimike]

after reading over the thread I just saw this:

Using DEFINE OSC 20 I had erroneous results on the LCD, so it's obviously a timing issue with your 4MHz resonator

I took out my resonator and used the chips' internal oscillator but I get the same results so this rules out the resonator I was using.

When using LCD_AnyPin it works with 8 MHz but the timing is doubled, if I set to 4 MHz the timing is is ok and LCD is blank.

Furthermore using standard settings for LCD does not work at all settings for OSC.

Help!

[mackrackit]

The only suggestion I have now is to play with these lines.

DEFINE LCD_COMMANDUS 2000       ' Command delay time in us 
DEFINE LCD_DATAUS 50            ' Data delay time in us

Use the 4 MHZ OSC
DEFINE OSC 4

[malc-c]

after reading over the thread I just saw this:


I took out my resonator and used the chips' internal oscillator but I get the same results so this rules out the resonator I was using.

When using LCD_AnyPin it works with 8 MHz but the timing is doubled, if I set to 4 MHz the timing is is ok and LCD is blank.

Furthermore using standard settings for LCD does not work at all settings for OSC.

Help!

Mike,

That's why I included the statement. With a 20Mhz xtal and setting the define to 20 I got random parts of the text displayed. When I set the define to 48 it worked - why I don't know (I'm still a newb to a degree My guess is that the value is divided internally somewhere to set the timing, which is why in your case setting it to 8 works with a 4Mhz xtal