Hi I'm new here. and I am currently doing a project on Toxic Gas Release
Alarm system using PIC.

I'm using PIC16f84a and I have used several I/O pins for LEDs, speakers &
a/d converters. and only I/O 6 pins left for LCD. (R0A,RB3-RB7). I'm using
LCD Serial port with 8 pads(www.cytron.com.my). 

any ideas how I can connect the LCD to the PIC without using all the pads?
can i just connect the lcd to the pic with 3 connection? vcc,vdd and serial
data (RB7)? will that work?



	   
					
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The interface for this display can be driven in 4 or 8 bit mode. In 4 bit 
mode you only need 6 pins. 

zss wrote:
> Hi I'm new here. and I am currently doing a project on Toxic Gas Release
> Alarm system using PIC.
> 
> I'm using PIC16f84a and I have used several I/O pins for LEDs, speakers &
> a/d converters. and only I/O 6 pins left for LCD. (R0A,RB3-RB7). I'm using
> LCD Serial port with 8 pads(www.cytron.com.my). 

Which LCD are you talking about here ??

> 
> any ideas how I can connect the LCD to the PIC without using all the pads?
> can i just connect the lcd to the pic with 3 connection? vcc,vdd and serial
> data (RB7)? will that work?

Normal LCD controllers do not have a serial port on them.

A serial to LCD backpack can be used but thats adding another CPU to the 
system.

A normal LCD panel will work with just 6 pins connected.

Four data pins [DB4-DB7]
Two control pins R/C & E, with R/W pin pulled low.

Google for Hitachi Hd44780 controller specs and code available.

don

zss wrote:
> Hi I'm new here. and I am currently doing a project on Toxic Gas Release
> Alarm system using PIC.
> 
> I'm using PIC16f84a and I have used several I/O pins for LEDs, speakers &
> a/d converters. and only I/O 6 pins left for LCD. (R0A,RB3-RB7). I'm using
> LCD Serial port with 8 pads(www.cytron.com.my). 
> 
> any ideas how I can connect the LCD to the PIC without using all the pads?
> can i just connect the lcd to the pic with 3 connection? vcc,vdd and serial
> data (RB7)? will that work?

No, see:
http://www.dontronics-shop.com/faqs-micro-or-electronics-specific-questions.html#lcd

Cheers Don...



-- 
Don McKenzie

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>The interface for this display can be driven in 4 or 8 bit mode. In 4 bit

>mode you only need 6 pins. 
>
>

So there is no need for me to use a serial lcd then. I can just use the
parallel 16x2 lcd eh. thanks guys!  I didnt know that :). I'm new to this
thing.haha

So, the next thing I need to learn is how to code the 4 bit mode lcd using
assembly language. Any ideas where I can find any simple examples I can
learn from? :) 
I'm using MPLab IDE btw.

very much appreciated.	   
					
---------------------------------------		
This message was sent using the comp.arch.embedded web interface on
http://www.EmbeddedRelated.com

zss wrote:
>> The interface for this display can be driven in 4 or 8 bit mode. In 4 bit
> 
>> mode you only need 6 pins. 
>>
>>
> 
> So there is no need for me to use a serial lcd then. I can just use the
> parallel 16x2 lcd eh. thanks guys!  I didnt know that :). I'm new to this
> thing.haha
> 
> So, the next thing I need to learn is how to code the 4 bit mode lcd using
> assembly language. Any ideas where I can find any simple examples I can
> learn from? :) 


http://tinyurl.com/yhvf8b5

> I'm using MPLab IDE btw.
> 
> very much appreciated.	   
> 					
> ---------------------------------------		
> This message was sent using the comp.arch.embedded web interface on
> http://www.EmbeddedRelated.com