HD44780, 4 * 16 LCD

[tim]

Hi

I have a 4 row lcd. How do i modify the lcd.c driver from its existing 2 row format.
I have added in the extra rows using a switch in the LCD_GOTOXY function and obviously some defines like
#define lcd_line_two 0x40
#define lcd_line_three 0x60
#define lcd_line_four 0x80 are these correct???

however its the following lines that i do not know how to change
#define lcd_type 2
and
byte CONST LCD_INIT_STRING[4] = {0x20 | (lcd_type << 2), 0xc, 1, 6};

The function set information in my data sheet only seems to cope with 2 lines.
My compiler version is 3.058

Hoping for an answer, thanks
___________________________
This message was ported from CCS's old forum
Original Post ID: 3274

[alex]

hi, this is driver lcd4.c. I use that and is good. bye

////////////////////////////////////////////////////////////////////////////
//// LCD4.C ////
//// Driver for common LCD 4 row 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 ////
//// ////
////////////////////////////////////////////////////////////////////////////
//// ////
//// ////
//// ////
//// ////
//// ////
//// ////
//// ////
////////////////////////////////////////////////////////////////////////////

// As defined in the following structure the pin connection is as follows:
// B0 enable
// B1 rs
// B2 rw
// B4 D4
// B5 D5
// B6 D6
// B7 D7
//
// LCD pins D0-D3 are not used and PIC B3 is not used.

struct lcd_pin_map { // This structure is overlayed
boolean enable; // on to an I/O port to gain
boolean rs; // access to the LCD pins.
boolean rw; // The bits are allocated from
boolean unused; // low order up. ENABLE will
int data : 4; // be pin B0.
} lcd;

#byte lcd = 6 // This puts the entire structure
// on to port B (at address 6)

#define lcd_type 2 // 0=5x7, 1=5x10, 2=2 lines
#define lcd_line_two 0x40 // LCD RAM address for the second line
#define lcd_line_three 0x14 // LCD Ram address for the 3 line
#define lcd_line_four 0x54 // LCD Ram address for the 4 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.
byte address;

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 = {0,0,0,0,15}; // For read mode data pins are in




byte lcd_read_byte() {
byte low,high;

set_tris_b(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_b(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 address1, byte n ) {

lcd.rs = 0;
while ( bit_test(lcd_read_byte(),7) ) ;
lcd.rs = address1;
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_b(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]);
address=00;
}


void lcd_gotoxy( byte x, byte y) {


switch(y){
case 1: address= 00; break;
case 2: address= lcd_line_two; break;
case 3: address= lcd_line_three; break;
default: address= lcd_line_four; break;
}

address+=x-1;
lcd_send_byte(0,0x80|address);
}

void lcd_gotonl (){
switch(address){
case 00 : address= lcd_line_two; break;
case lcd_line_two : address= lcd_line_three; break;
case lcd_line_three: address= lcd_line_four; break;
default : address= 00; break;
}
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_gotonl(); 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);
lcd.rs=1;
value = lcd_read_byte();
lcd.rs=0;
return(value);
}







:=Hi
:=
:=I have a 4 row lcd. How do i modify the lcd.c driver from its existing 2 row format.
:=I have added in the extra rows using a switch in the LCD_GOTOXY function and obviously some defines like
:=#define lcd_line_two 0x40
:=#define lcd_line_three 0x60
:=#define lcd_line_four 0x80 are these correct???
:=
:=however its the following lines that i do not know how to change
:=#define lcd_type 2
:=and
:=byte CONST LCD_INIT_STRING[4] = {0x20 | (lcd_type << 2), 0xc, 1, 6};
:=
:=The function set information in my data sheet only seems to cope with 2 lines.
:=My compiler version is 3.058
:=
:=Hoping for an answer, thanks
___________________________
This message was ported from CCS's old forum
Original Post ID: 3292

[tim]

Thank you very much Alex...your a star!





:=hi, this is driver lcd4.c. I use that and is good. bye
:=
:=////////////////////////////////////////////////////////////////////////////
:=//// LCD4.C ////
:=//// Driver for common LCD 4 row 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 ////
:=//// ////
:=////////////////////////////////////////////////////////////////////////////
:=//// ////
:=//// ////
:=//// ////
:=//// ////
:=//// ////
:=//// ////
:=//// ////
:=////////////////////////////////////////////////////////////////////////////
:=
:=// As defined in the following structure the pin connection is as follows:
:=// B0 enable
:=// B1 rs
:=// B2 rw
:=// B4 D4
:=// B5 D5
:=// B6 D6
:=// B7 D7
:=//
:=// LCD pins D0-D3 are not used and PIC B3 is not used.
:=
:=struct lcd_pin_map { // This structure is overlayed
:= boolean enable; // on to an I/O port to gain
:= boolean rs; // access to the LCD pins.
:= boolean rw; // The bits are allocated from
:= boolean unused; // low order up. ENABLE will
:= int data : 4; // be pin B0.
:= } lcd;
:=
:=#byte lcd = 6 // This puts the entire structure
:= // on to port B (at address 6)
:=
:=#define lcd_type 2 // 0=5x7, 1=5x10, 2=2 lines
:=#define lcd_line_two 0x40 // LCD RAM address for the second line
:=#define lcd_line_three 0x14 // LCD Ram address for the 3 line
:=#define lcd_line_four 0x54 // LCD Ram address for the 4 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.
:=byte address;
:=
:=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 = {0,0,0,0,15}; // For read mode data pins are in
:=
:=
:=
:=
:=byte lcd_read_byte() {
:= byte low,high;
:=
:= set_tris_b(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_b(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 address1, byte n ) {
:=
:= lcd.rs = 0;
:= while ( bit_test(lcd_read_byte(),7) ) ;
:= lcd.rs = address1;
:= 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_b(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]);
:= address=00;
:=}
:=
:=
:=void lcd_gotoxy( byte x, byte y) {
:=
:=
:= switch(y){
:= case 1: address= 00; break;
:= case 2: address= lcd_line_two; break;
:= case 3: address= lcd_line_three; break;
:= default: address= lcd_line_four; break;
:= }
:=
:= address+=x-1;
:= lcd_send_byte(0,0x80|address);
:=}
:=
:=void lcd_gotonl (){
:= switch(address){
:= case 00 : address= lcd_line_two; break;
:= case lcd_line_two : address= lcd_line_three; break;
:= case lcd_line_three: address= lcd_line_four; break;
:= default : address= 00; break;
:= }
:= 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_gotonl(); 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);
:= lcd.rs=1;
:= value = lcd_read_byte();
:= lcd.rs=0;
:= return(value);
:=}
:=
:=
:=
:=
:=
:=
:=
:=:=Hi
:=:=
:=:=I have a 4 row lcd. How do i modify the lcd.c driver from its existing 2 row format.
:=:=I have added in the extra rows using a switch in the LCD_GOTOXY function and obviously some defines like
:=:=#define lcd_line_two 0x40
:=:=#define lcd_line_three 0x60
:=:=#define lcd_line_four 0x80 are these correct???
:=:=
:=:=however its the following lines that i do not know how to change
:=:=#define lcd_type 2
:=:=and
:=:=byte CONST LCD_INIT_STRING[4] = {0x20 | (lcd_type << 2), 0xc, 1, 6};
:=:=
:=:=The function set information in my data sheet only seems to cope with 2 lines.
:=:=My compiler version is 3.058
:=:=
:=:=Hoping for an answer, thanks
___________________________
This message was ported from CCS's old forum
Original Post ID: 3299