Need simple code for LCD use ATmega16 and IAR copiletor C la

[brolija2dekan]

lcd+atmega16+c

Hi, can anyone please post a simple LCD code for me?
I just need to know how to show a word in a 2x16 LCD. I'm using ATmega16 and
IAR Workbench for AVR compiletor need C code

 

[ashad]

atmega16 lcd

please any one has the IAR programming manual for AVR controller please upload it
i am facing problem in IAR (AVR) tool box

 

[foxbrain]

what about using avr studio? how would the code be?

 

[alexxx]

i am facing problem in IAR (AVR) tool box

What is the exact problem?

 

[foxbrain]

I had known the basics of the lcd...
and the question is how can i determine where i can write on the lcd (like to write on the middle of the second line) what is the code of it???should i use lcd instruction : 00000001xx?

 

[alexxx]

how can i determine where i can write on the lcd

should i use lcd instruction : 00000001xx?

Assuming that the LCD_Instruction() routine works well, you should first set the cursor to the desired address:

LCD_Instruction(0xCA);  //Somewhere in the middle of the second line of a 4x20 lcd

Then if you want to write character:

LCD_Data('H');  //Display character on address 0xCA
LCD_Data('I');  //Display character on address 0xCB

Regards,
Alexandros

 

[foxbrain]

LCD_Instruction(0xCA);

what is this function? and what is this value CA?
Note this is my code and it's working good:



/*----------------------------------------------------------------
-----------------HEADER FILES-------------------------------------
-----------------------------------------------------------------*/
#include<avr/io.h>
#include <util/delay.h>


#define SETBIT(ADDRESS,BIT) (ADDRESS |= (1<<BIT))
#define CLEARBIT(ADDRESS,BIT) (ADDRESS &= ~(1<<BIT))
#define CHECKBIT(ADDRESS,BIT) (ADDRESS & (1<<BIT))

/*----------------------------------------------------------------
-------------CONNECTION BETWEEN LCD AND ATMEGA32-----------------
-----------------------------------------------------------------*/
#define DATA_DDR DDRB
#define DATA_PORT PORTB


#define CONTROL_DDR DDRA
#define CONTROL_PORT PORTA
#define Enable_Pin 2
#define RegSelect_Pin 0
#define ReadWrite_Pin 1
#define CONTROL_MASK 0X07


/*----------------------------------------------------------------
-------------CONTROL BITS OF LCD --------------------------------
-----------------------------------------------------------------*/

#define Set_Enable CONTROL_PORT|=_BV(Enable_Pin)
#define Clear_Enable CONTROL_PORT&=~_BV(Enable_Pin)
#define Write_Lcd CONTROL_PORT&=~_BV(ReadWrite_Pin)
#define Read_Lcd CONTROL_PORT|=_BV(ReadWrite_Pin)
#define Select_InstructionRegister CONTROL_PORT&=~_BV(RegSelect_Pin)
#define Select_DataRegister CONTROL_PORT|=_BV(RegSelect_Pin)
#define Data_Lcd(a) DATA_PORT=a
#define delay(a) _delay_ms(a)




/*----------------------------------------------------------------
-----------------SEND A CHARACTER TO LCD-------------------------
-----------------------------------------------------------------*/
void Lcd_Send(unsigned char a)
{
CLEARBIT(PORTD,2);
Select_DataRegister;
Write_Lcd;
Data_Lcd(a);
Set_Enable;
delay(30);
Clear_Enable;
delay(30);
}






/*----------------------------------------------------------------
-----------------FUNCTIONS TO INITIALIZE PORTS--------------------
-----------------------------------------------------------------*/
void Init_Ports(void)
{
CLEARBIT(PORTC,0);
DATA_DDR=0XFF; //Setting data port for output
CONTROL_DDR=CONTROL_MASK;//setting selected pins of control port for output
CONTROL_PORT&=~(_BV(Enable_Pin)|_BV(RegSelect_Pin )|_BV(ReadWrite_Pin)); //setting values to 0 at starting
}




/*----------------------------------------------------------------
------------FUNCTION TO INITIATE LCD -----------------------------
-----------------------------------------------------------------*/
void Init_Lcd(void)
{
CLEARBIT(PORTC,1);
char init[10];
int i;
init[0] = 0x01;
init[1] = 0x38;
init[2] = 0x0c;
init[3] = 0x06;
init[4] = 0x80;
Select_InstructionRegister;
Write_Lcd;
for(i=0;i<5;i++)
{
Data_Lcd(init);
Set_Enable;
delay(30);
Clear_Enable;
delay(30);
}
}


/*----------------------------------------------------------------
----------------MAIN FUNCTION--------------------------------------
-----------------------------------------------------------------*/
int main(void)
{
DDRC=0xFF;
PORTC=0x00;
DDRD=0xFF;
PORTD=0x00;
SETBIT(PORTC,0);
SETBIT(PORTC,1);
SETBIT(PORTD,2);
int len,i;
char string[] = {'H','E','L','L','O',' ','J','O','J','O'};
Init_Ports();
//CLEARBIT(PORTC,0);
Init_Lcd();
//CLEARBIT(PORTC,1);
len=10;
for (i=0; i< len;i++)
Lcd_Send(string);


//CLEARBIT(PORTD,2);
}


so my main question is what are the addresses that determine the place we write on the LCD?

 

[alexxx]

LCD_Instruction(0xCA);

what is this function? and what is this value CA?

0xCA is the cursor position. I use 4x20 LCD, so the printable characters are 80. Each one has an address. Those 80 addresses are:

Line1 addresses: 0x80 to 0x93
Line2 addresses: 0xC0 to 0xD3
Line3 addresses: 0x94 to 0xA7
Line4 addresses: 0xD4 to 0xE7

According to the above table, the middle of line 2 will be address 0xC9. So following your function names, if you want to display a "HI" on the middle of line 2 that would be:

Data_Lcd(0xC9);  //Set cursor at the desired address
Lcd_Send('H');  //print an 'H' at address 0xC9
Lcd_Send('I');  //print an 'I' at address 0xCA

Hope that helped.

 

[foxbrain]

are these addresses general in all lcds (i don't think so).
how can i know that for my lcds (that is 16X02)and i'll attach the datasheet of it?

 

[alexxx]

are these addresses general in all lcds

Yes they are the same. I think than in a 2x16 LCD the two lines start from the same address (0x80 - 0xC0). To be accurate the address is 0x00 and 0x40, and the command is 0x80+DDRAM address. Anyway, try 0x80 and 0xC0 and tell us what happened.

 

[foxbrain]

ya it worked i had to change init[4] = 0x80; (0x80 to what address i want to start with)...
thanks.
......................

 

[foxbrain]

i've got another question how can i write a function that can check if the lcd is busy or not?
as i know i have to set R/W to high and RS to low to read the busy flag and then what shall i do?