Source code of LCD2004 driven by ATmega16 (avr)

/*================================================
20x4 character LCD main program, compilation software (ICCAVR_6.31)
CPU internal crystal oscillator 8M
data line B0~B7 connects PORTB, E=D7 RW=D6 RS=D5
=======================================================
The wiring diagram is as follows:
_______________ ______________
| --1|GND |
| --2| 5V |
| --3|V0 |
| | |
PD5|--------4|RS |
PD6|--------5|RW |
PD7|--------6|E |
CPU | | |
ATmmega16L PB0|--------7|D0 LCD20x4 |
PB1|--------8|D1 |
PB2|--------9|D2 |
PB3|-------10|D3 |
PB4|-------11|D4 |
PB5|-------12|D5 |
PB6|-------13|D6 |
PB7|-------14|D7 |
| | |
| --15| LED |
| --16|-LED |
_______________| |______________|
==============================================================*/
#include //CPU_ATmmega16L
#define RS_H asm("sbi 0x12,5") //RS set to high level
#define RS_L asm("cbi 0x12,5") //RS is set to low level
#define RW_H asm("sbi 0x12,6
") //RW is set to high level#define RW_L asm("cbi 0x12,6") //RW is set to low level
#define E_H asm("sbi 0x12,7") //E is set to high level
#define E_L asm("cbi 0x12,7") //E is set to low level

//=========================================================
//microsecond delay program
void delay_us(int time)
{
do
{
time--;
}
while (time > 1);
}
//===========================================================
//millisecond delay program
void delay_ms(unsigned int time)
{
while(time != 0)
{
delay_us(1000);
time--;
}
}

//=======================================================
//Read whether the LCD is in internal operation (busy) status
char Lcd_Busy()
{
char r;
DDRB = 0x00; //Port B is set to input mode
E_L;RS_L;RW_H; //E=0 (enable), RS=0 (command), RW=1 (read)
delay_us(2); //LCD delay subroutine
E_H;
delay_us(2); //LCD delay subroutine
r = PINB & 0x80; //Read the eighth bit of lcd_data
E_L;
DDRB=0xff; //Port B is set to output mode
return r; //Read result return
}

//=======================================================
//Send command program to LCD
void Lcd_Command(unsigned char Command)
{
while(Lcd_Busy()); //Judge whether LCD is in internal operation state
E_L;RS_L;RW_L; //E=0(enable),RS=0(command),RW=0(write)
delay_us(2); //LCD delay subroutine
E_H;
PORTB = Command; //Send command to LCD
delay_us(2); //LCD delay subroutine
E_L;
}

//=======================================================
//Program to write a character to the LCD
void Lcd_Write(unsigned char Data)
{
while(Lcd_Busy()); //Judge whether the LCD is in internal operation status
E_L;RS_H;RW_L; //E=0(enable),RS=1(data),RW=0(write)
delay_us(2); //LCD delay subroutine
E_H;
PORTB = Data; //Write a character to the LCD
delay_us(2); //LCD delay subroutine
E_L;
}

/*=============================================================
LCD line 1 displays address 1~20 (0x80~0x93)
LCD line 2 displays address 1~20 (0xc0~0xd3)
LCD line 3 displays address 1~20 (0x94~0xa7) LCD line
4 displays address 1~20 (0xd4~ 0xe7 ) ===
... //Set port D to output mode Lcd_Command(0x38); // Lcd_Command (0x38); // Lcd_Command(0x38); // Lcd_Command(0x38); // Lcd_Command(0x08); //Turn the display off Lcd_Command(0x01); //Clear the display Lcd_Command( 0x06); //Set the LCD to automatically increase AC by 1 after receiving 1 Byte of data Lcd_Command(0x0C); //Set the cursor, 0x0c = do not display, 0x0d = display flashing. }

//========================================================
//Write ASCII string program
void asc_tran(unsigned char *asc)
{
while((*asc) != 0) //Judge whether the word ends
{
Lcd_Write(*asc); //Write string asc to LCD
; //Move to the next character
}
}

//========================================================
//Test main LCD main program
void main()
{
Lcd_Init(); //Initialize LCD
while(1)
{
Lcd_Command(0x83); //Set display address
asc_tran("-----@_@------"); //Display string
Lcd_Command(0x97); //Set display address
asc_tran("www.ouravr.com"); //Display string
delay_ms(1000); //Delay 1 second
Lcd_Command(0x01); //Clear display

Lcd_Command(0x83); //Set display address
asc_tran("-----^_^------"); //Display string
Lcd_Command(0x94); //Set display address
asc_tran("http://59.36.96.196"); //Display string
delay_ms(1000); //Delay
Lcd_Command(0x01); //Clear display
}
}