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Bryan
Joined: 23 Apr 2005
Posts: 73
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 Posted: Wed May 18, 2005 4:41 pm |
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Thank you for the help everyone! PCM programmer, thank you for calling my attention to that! I totally overlooked it and when I updated that line it worked perfectly. Surprising thing here is that once I saw that it worked, I pulled out the pullup resistor that I was using for RA4 since it is open drain just to see what would happen and it still worked fine! Maybe the output signal from that port is just high enough to be detected by the LCD? Here is my working main code and driver (changes bolded):
| Code: |
#include <18F1220.h>
#fuses NOWDT,NOPROTECT,NOLVP,NOMCLR,INTRC_IO// CCPB0
#use delay(clock=8000000)
#include "lcdporta.c"
void main()
{
output_a(0x00);
setup_adc(NO_ANALOGS);
lcd_init();
lcd_putc("\fHello");
}
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Driver code:
| Code: |
///////////////////////////////////////////////////////////////////////////
//// LCDD.C ////
//// Driver for common LCD modules ////
//// ////
//// lcd_init() Must be called before any other function. ////
//// ////
//// lcd_putc(c) Will display c on the next position of the LCD. ////
//// The following have special meaning: ////
//// \f Clear display ////
//// \n Go to start of second line ////
//// \b Move back one position ////
//// ////
//// lcd_gotoxy(x,y) Set write position on LCD (upper left is 1,1) ////
//// ////
//// lcd_getc(x,y) Returns character at position x,y on LCD ////
//// ////
///////////////////////////////////////////////////////////////////////////
//// (C) Copyright 1996,2003 Custom Computer Services ////
//// This source code may only be used by licensed users of the CCS C ////
//// compiler. This source code may only be distributed to other ////
//// licensed users of the CCS C compiler. No other use, reproduction ////
//// or distribution is permitted without written permission. ////
//// Derivative programs created using this software in object code ////
//// form are not restricted in any way. ////
///////////////////////////////////////////////////////////////////////////
// As defined in the following structure the pin connection is as follows:
// A0 D4
// A1 D5
// A2 D6
// A3 D7
// A4 RW
// A6 RS
// A7 E
//
// LCD pins D0-D3 are not used and PIC D3 is not used.
// Un-comment the following define to use port B
#define use_porta_lcd TRUE
struct lcd_pin_map {
int data : 4; //Pins A0-A3
BOOLEAN rw; //Pin A4
BOOLEAN DUMMY; //Pin A5
BOOLEAN rs; //Pin A6
BOOLEAN enable; //Pin A7
} lcd;
#if defined(__PCH__)
#if defined use_porta_lcd
#byte lcd = 0xF80 // This puts the entire structure
#else
#byte lcd = 0xF83 // This puts the entire structure
#endif
#else
#if defined use_porta_lcd
#byte lcd = 5 // on to port B (at address 6)
#else
#byte lcd = 8 // on to port D (at address 8)
#endif
#endif
#if defined use_porta_lcd
#define set_tris_lcd(x) set_tris_a(x)
#else
#define set_tris_lcd(x) set_tris_d(x)
#endif
#define lcd_type 2 // 0=5x7, 1=5x10, 2=2 lines
#define lcd_line_two 0x40 // LCD RAM address for the second line
BYTE const LCD_INIT_STRING[4] = {0x20 | (lcd_type << 2), 0xc, 1, 6};
// These bytes need to be sent to the LCD
// to start it up.
// The following are used for setting
// the I/O port direction register.
struct lcd_pin_map const LCD_WRITE = {0,0,0,0,0}; // For write mode all pins are out
[b]struct lcd_pin_map const LCD_READ = {15,0,0,0,0}; // For read mode data pins are in[/b]
BYTE lcd_read_byte() {
BYTE low,high;
set_tris_lcd(LCD_READ);
lcd.rw = 1;
delay_cycles(1);
lcd.enable = 1;
delay_cycles(1);
high = lcd.data;
lcd.enable = 0;
delay_cycles(1);
lcd.enable = 1;
delay_us(1);
low = lcd.data;
lcd.enable = 0;
set_tris_lcd(LCD_WRITE);
return( (high<<4) | low);
}
void lcd_send_nibble( BYTE n ) {
lcd.data = n;
delay_cycles(1);
lcd.enable = 1;
delay_us(2);
lcd.enable = 0;
}
void lcd_send_byte( BYTE address, BYTE n ) {
lcd.rs = 0;
while ( bit_test(lcd_read_byte(),7) ) ;
lcd.rs = address;
delay_cycles(1);
lcd.rw = 0;
delay_cycles(1);
lcd.enable = 0;
lcd_send_nibble(n >> 4);
lcd_send_nibble(n & 0xf);
}
void lcd_init() {
BYTE i;
set_tris_lcd(LCD_WRITE);
lcd.rs = 0;
lcd.rw = 0;
lcd.enable = 0;
delay_ms(15);
for(i=1;i<=3;++i) {
lcd_send_nibble(3);
delay_ms(5);
}
lcd_send_nibble(2);
for(i=0;i<=3;++i)
lcd_send_byte(0,LCD_INIT_STRING[i]);
}
void lcd_gotoxy( BYTE x, BYTE y) {
BYTE address;
if(y!=1)
address=lcd_line_two;
else
address=0;
address+=x-1;
lcd_send_byte(0,0x80|address);
}
void lcd_putc( char c) {
switch (c) {
case '\f' : lcd_send_byte(0,1);
delay_ms(2);
break;
case '\n' : lcd_gotoxy(1,2); break;
case '\b' : lcd_send_byte(0,0x10); break;
default : lcd_send_byte(1,c); break;
}
}
char lcd_getc( BYTE x, BYTE y) {
char value;
lcd_gotoxy(x,y);
while ( bit_test(lcd_read_byte(),7) ); // wait until busy flag is low
lcd.rs=1;
value = lcd_read_byte();
lcd.rs=0;
return(value);
}
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Mark
Joined: 07 Sep 2003
Posts: 2838
Location: Atlanta, GA
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| Posted: Wed May 18, 2005 5:52 pm |
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Maybe there is a pullup on the LCD  |
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ice
Joined: 30 May 2005
Posts: 10
Location: India
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| Posted: Mon May 30, 2005 6:08 am |
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Hello,
I cant figure out what the following lines do in the LCD.c driver
| Code: | struct lcd_pin_map const LCD_WRITE = {0,0,0,0,0}; // For write mode all pins are out
struct lcd_pin_map const LCD_READ = {15,0,0,0,0}; // For read mode data pins are in |
what does {15,0,0,0,0} mean?
Thank you
_________________
**ice**
Machinegrid.com :: Robots at Work!! |
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rwyoung
Joined: 12 Nov 2003
Posts: 563
Location: Lawrence, KS USA
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| Posted: Mon May 30, 2005 7:41 am |
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| ice wrote: | Hello,
I cant figure out what the following lines do in the LCD.c driver
| Code: | struct lcd_pin_map const LCD_WRITE = {0,0,0,0,0}; // For write mode all pins are out
struct lcd_pin_map const LCD_READ = {15,0,0,0,0}; // For read mode data pins are in |
what does {15,0,0,0,0} mean?
Thank you |
Look at the structure. It is going to put 15 into the "data" variable, clear "rw", clear "DUMMY", clear "rs" and clear "enable" when you assign the newly made constant LCD_READ to your #byte'd variable "lcd".
_________________
Rob Young
The Screw-Up Fairy may just visit you but he has crashed on my couch for the last month! |
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ice
Joined: 30 May 2005
Posts: 10
Location: India
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Guest
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| Posted: Tue May 31, 2005 1:56 pm |
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what about making PORTA digital?
Andre |
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