how to configure LCD using 16f913

[deepakomanna]

Dear Sir,
here i am using 16f913, MPLAB 7.5 Ver. & CCS PCM C Compiler, Version 3.249, 34534.
1st time i am using this lcd driver.
I read Ex_92lcd.c but i didnt understand this,
[/code]//
Digit segments A B C D E F G DP
// b7 b6 b5 b4 b3 b2 b1 b0
#define DIGIT4 COM1+26, COM1+17, COM2+17, COM3+26, COM2+25, COM1+25, COM2+26, COM3+17
#define DIGIT3 COM1+24, COM1+16, COM2+16, COM3+24, COM2+23, COM1+23, COM2+24, COM3+16
#define DIGIT2 COM1+22, COM1+19, COM2+19, COM3+22, COM2+21, COM1+21, COM2+22, COM3+19
#define DIGIT1 COM1+20, COM1+18, COM2+18, COM3+20, COM2+28, COM1+28, COM2+20, COM3+18

In this example How you did COM1+24,COM2+17,COM3+26 etc & etc.
So plz tell me how enable the segments to display the numbers 0 to 9
_________________
Thank You,
With Best Regards,
Deepak.

[PCM programmer]

I don't have the CCS LCD demo board, but here's how I think it works:

The Ex_92lcd.c file shows how to use a PIC 16C924 with a multiplexed
drive LCD that has 3 common (COM) pins and 12 segment pins.
The #define statements shown in your post are used to tell the CCS
lcd functions about the connections between the PIC and the LCD pins.
These connections are made with traces on a printed circuit board.

To understand how the connections are selected, you need to download
the data sheets for the PIC and the LCD.

Download the 16C924 data sheet here:
http://ww1.microchip.com/downloads/en/DeviceDoc/30444e.pdf
The PIC pins are shown on page 3 for the PLCC package. Notice that it
has pins for SEG00 to SEG28, and it also has pins for COM0 to COM3.
The Ex_92lcd.c file uses 12 segment pins on the right side of the PLCC
package: SEG16-SEG28 (There is no SEG27 pin). This is done to allow
making an easy printed circuit board layout.

I don't know for certain what LCD is used by CCS, but I think it's
probably similar to the Varitronix VIM-404-DP:
http://www.varitronix.com/Product/LCD/VIM-404-DP(R0).pdf
This LCD has 4 digits and 3 decimal points. It has 12 pins for the LCD
segments and 3 pins for the COM signals. The important pages in the
data sheet are:
Page 2: Shows the names of the segments in a digit (letters: a-g).
Page 4: Shows the 12 segment connections.
Page 5: Shows the 3 common connections.

Assuming that the Varitronix LCD is used by CCS, here are the
connections between the LCD and the PIC, as given in Ex_92lcd.c: