Anyone used a serial LCD with a PIC?

[Natalia]

In particular, I'm trying to use one of the ones that Parallax sells. I'm a bit confused as to how to connect it and how to write to it.

The docs that come with it, have an example of connecting it to a general purpose I/O pin of a Basic Stamp -- not the UART! Is this correct? Even though this is a serial device?

Also, I'm assuming that I can't use the CCS C LCD functions because they are for a parallel interface LCD?

Any info is greatly appreciated!

-- Natalia
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This message was ported from CCS's old forum
Original Post ID: 10217

[PCM programmer]

:=In particular, I'm trying to use one of the ones that Parallax sells. I'm a bit confused as to how to connect it and how to write to it.
:=
:=The docs that come with it, have an example of connecting it to a general purpose I/O pin of a Basic Stamp -- not the UART! Is this correct? Even though this is a serial device?
:=
:=Also, I'm assuming that I can't use the CCS C LCD functions because they are for a parallel interface LCD?
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No one else has answered this. Maybe they're on vacation this
week.

I assume you're using a LCD from Scott Edwards Electronics.
At this link, there's a schematic which shows how to connect
it to a PIC. Apparently, it only requires +5v, GND, and one
serial transmit wire from the PIC.
<a href="http://www.mastincrosbie.com/mark/electronics/pic/lcdtest.jpg" TARGET="_blank">http://www.mastincrosbie.com/mark/electronics/pic/lcdtest.jpg</a>
In your case, I assume you're using a 16F877, or a similar PIC
since you said you have a USART. So instead of using RA1
you can use PIN C6, which is the Tx pin for the hardware USART.

They have some sample code in this document. It's written
in BASIC.
<a href="http://www.seetron.com/pdf/bpi_bpk.pdf" TARGET="_blank">http://www.seetron.com/pdf/bpi_bpk.pdf</a>
I translated the first part of it into a simple CCS C program.
I can't test it because I don't have the LCD module.
But it can at least get you started.

#include "c:\program files\picc\devices\16F877.h"
#fuses HS,NOWDT,NOPROTECT,PUT,BROWNOUT, NOLVP
#use Delay(clock=8000000)
#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7, ERRORS)

#define I 254
#define CLR 1
#define LINE1 128
#define LINE2 192

void main(void)
{

putc(I);
putc(CLR);

putc(I);
putc(LINE1);

printf("Hello World!");

while(1); // Prevent PIC from going to sleep
}
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This message was ported from CCS's old forum
Original Post ID: 10233

[Natalia]

Thanks for the help. Will I need to use the INVERT option of #use RS232 if I'm not using a MAX232 and just hooking this device directly?

Thanks again for the help...

-- Natalia
___________________________
This message was ported from CCS's old forum
Original Post ID: 10234

[PCM programmer]

:=Thanks for the help. Will I need to use the INVERT option of #use RS232 if I'm not using a MAX232 and just hooking this device directly?
:=
------------------------------------------------------
If you use the hardware USART pin on the PIC, you will
need to invert the signals. But the hardware USART has no
built-in option to do this inversion. The INVERT directive
doesn't work with the hardware USART. You will need an
external MAX232 chip.

You could use a free i/o pin, as shown in the example drawing
that I posted earlier. Then you can use the INVERT option
in your #use RS232 statement. That's because the inversion
is done in software when you specify a normal i/o pin for
RS-232 output, with the CCS compiler.
___________________________
This message was ported from CCS's old forum
Original Post ID: 10235