How to send 1 bit command into ATMEGA128?

bianchi77 said:

Guys,
How to send 1 bit command into ATMEGA128?

I tried to send

PORTA.0 = 1;



but the compiler gives me an error.
I got this error :
../main.c:13:1: error: expected ';' before numeric constant


Any ideas ?
thanks

Click to expand...

aadhyatm said:

Assuming that you are using gcc

As I learned somewhere on avrfreak, I use macros add this just below #include
#define SETBIT(x,y) SETBITS((x), (BIT()))

Then use it as
SETBIT(PORTB, 2);
SETBIT(PORTD, 3);

and here are some more macro you will love to see

#define BIT(x) (1 << (x))
#define SETBITS(x,y) ((x) |= )
#define CLEARBITS(x,y) ((x) &= (~))
#define SETBIT(x,y) SETBITS((x), (BIT()))
#define CLEARBIT(x,y) CLEARBITS((x), (BIT()))
#define BITSET(x,y) ((x) & (BIT))
#define BITCLEAR(x,y) !BITSET((x), )
#define BITSSET(x,y) (((x) & ) == )
#define BITSCLEAR(x,y) (((x) & ) == 0)
#define BITVAL(x,y) (((x)>>) & 1)

Hope this help........

Click to expand...

#define rs(a)  (PORTB = (PORTB & ~_BV(PB0)) | ((a) << PB0))
#define rw(b)  (PORTB = (PORTB & ~_BV(PB1)) | ((b) << PB1))
#define en(c)  (PORTB = (PORTB & ~_BV(PB2)) | ((c) << PB2))

rs(0);
delay(1);
rs(1);

void lcd_command(unsigned char comm) // function to send command to LCD
{
lcd_data_pin=comm;
en(1);
rs(0);
rw(0);
_delay_ms(10);
en(0);
}

lcd_command(0x01);

jayanth.devarayanadurga said:

Try #define RS PORTB.0

RS = 1;
RS = 0;

Click to expand...

jayanth.devarayanadurga said:

I think the problem is with this line #define RS PORTB.0

I don't know AVR Studio 4. In mikroC we use something like this #define RS PORTB.F0. You have to check some AVR Studio 4 examples which will show how to define a bit.

Also try this

sbit RS = PORTB.0;

RS = 0;
RS = 1;

Click to expand...

jayanth.devarayanadurga said:

sbit RS at PORTB.0;

Click to expand...

#include <avr/io.h>
#include <util/delay.h>


 //structure to allow bit field operations, name conversions: PORTA.0 -> PORT_A.b0  PORTB.7 -> PORT_B.b7
typedef struct{ uint8_t b0:1;
                uint8_t b1:1;
                uint8_t b2:1;
                uint8_t b3:1;
                uint8_t b4:1;
                uint8_t b5:1;
                uint8_t b6:1;
                uint8_t b7:1; } bits;

// define all the ports of your microcontroller, add more ports depending on the available mcu ports

#define PORT_A (* (volatile bits *) &PORTA)
#define PIN_A (* (volatile bits *) &PINA)
#define DDR_A (* (volatile bits *) &DDRA)
 
int main (void)
{
  	
	DDRA = 0xFF;
	//lcd_ini();
  while(1)
    {
	    PORT_A.b0 = 0;
		_delay_ms(50);
		PORT_A.b0 = 1;
	
	
        

    }
}