Question on setting LCD up

[bryan1]

Hiya Guy's,
I'm on my next project using a 16f877a and I intend to use the 4 lower bits from portA to control the data lines in 4 bit mode. now the question is I can just label portA as lcd_data as is usually done, but what if I want to use the 2 remaing pins?. I've looked around on the net without finding any usefull answer so if someone can answer my query I'll appreciate it.

Cheers Bryan

 

[Nigel Goodwin]

Hiya Guy's,
I'm on my next project using a 16f877a and I intend to use the 4 lower bits from portA to control the data lines in 4 bit mode. now the question is I can just label portA as lcd_data as is usually done, but what if I want to use the 2 remaing pins?. I've looked around on the net without finding any usefull answer so if someone can answer my query I'll appreciate it.

Providing a label such as 'lcd_data' is simply a text replacement option, during assembly of the program every occurance of the text 'lcd_data' will be replaced by the number you assigned to it - or in this case, replaced by the number assigned to the port name you assigned to 'lcd_data'.

Hope that's clear! 8)

You can assign the same number (or port name) to any number of text names you like - as I said, it's simply repalced by the number assigned to it during assembly.

 

[mstechca]

Just make sure you are using a program that can be easily reinstalled.
because everything has bugs. :wink:

 

[Nigel Goodwin]

Just make sure you are using a program that can be easily reinstalled.
because everything has bugs. :wink:

Are you perhaps on some strange 'chemical experience'?, two completely useless posts in a row is a record even for you!.

 

[mstechca]

Are you perhaps on some strange 'chemical experience'?, two completely useless posts in a row is a record even for you!.

Excuse me?
USELESS posts?
:lol:
At least I'm trying to help.

I could see now that any technical user with a broken hard drive is likely to buy one, put XP on it, and realize they have to install several win XP patches before being able to use a program, because the program may require those installed XP patches to work.

Don't tell me you never had to fight with Windows.

 

[bryan1]

Are you perhaps on some strange 'chemical experience'?, two completely useless posts in a row is a record even for you!.

Excuse me?
USELESS posts?
:lol:
At least I'm trying to help.

I could see now that any technical user with a broken hard drive is likely to buy one, put XP on it, and realize they have to install several win XP patches before being able to use a program, because the program may require those installed XP patches to work.

Don't tell me you never had to fight with Windows.

I tend to agree with Nigel on this one. The 2 posts you've done in this thread has nothing to do with the topic and what in the hell has windo$e xp got to do with setting up a LCD :?: I'm starting to think you would be better off learning " Would you like fries with that order" as 99% of your posts are complete rubbish.

 

[tkvenki]

Hi,

I would use this.


typedef struct
{
unsigned lcd_pins : 4; //This allocates 4 bits
unsigned remaining : 2; // you said uyou have to use two remaining //pins
}PORT_STRUCT;

PORT_STRUCT port_use; // a variable

THen in my code port_use.lcd_pins = 0x0; // any value like that.

This method may work out for you.