AVR Freaks

Also, PINC is read several times for a single set of tests.

That might be okay, but being sure of that might require major thinking.

Simpler to read PINC once and test the copy.

And have you turned of JTAG?

MCUCSR undeclared

Does you chip have MCUCSR or is it called something else?

Read and think about what I quotes above.  Early code and discussion said that port C is used for keypad interfacing.

Later code does nothing with port C.  And the "init" routines deal with port D.  Which earlier you said w2as used for something else.

You have been given links to two good articles on matrix keypad interfacing.  One has GCC code.  Study them.

[and you have never given us a wiring diagram, nor told whether there are diodes in your keypad, nor whether you intend to handle multiple presses]

} while (keypressed=0XFF);

I'm rather guessing that "=" was originally destined to become "==" in fact ;-)

PS a lot of people find this counter-intuitive (I know I do!) but you can avoid this kind of error by reversing the test:

} while (0xFF == keypressed);

On the occasion you mis-type that as:

} while (0xFF = keypressed);

the compiler simply won't let you get away with making that mistake (you cannot assign a variable to a constant!).

Your read_key() routine appears to be this:

unsigned char read_key(void)
{
	unsigned char value;
	col_init();
	value = 0;
	
	if(!(PINC & 0X10))
	{
		value = 0X01;
		_delay_ms(50);
	}
	else if(!(PINC & 0X20))
	{
		value = 0X02;
		_delay_ms(50);
	}
	else if(!(PINC & 0X40))
	{
		value = 0X03;
		_delay_ms(50);
	}

etc.

So that seems to be setting the returned value to low numbers like 0x01, 0x02, 0x03 etc. But then you do:

buffer[i]=keypressed;

and then finally:

Lcd8_Write_String(buffer);

So how on earth is that going to work? There is nothing here to convert 0x01, 0x02, 0x03 into '1', '2', '3' or whatever. Did you mistakenly think that 0x01, 0x02 etc in a buffer[] was going to appear as "123" ? It won't.

If you want the result of read_key to be "printable" then consider:

keypressed = read_key() + '0';

where the + '0' will convert 1,2,3 into '1', '2', '3' etc.

As highlighted above - you may well do:

			char buffer[8], i=0;

where i is set to 0. But then you:

			while(1)

and within that:

								buffer[i] = keypressed;
								i++;

and nothing ever sets i back to 0 again. Once you have consumed the buffer:

										Lcd8_Write_String(buffer);

then you should set i = 0.

BTW what is up with the indentation in your code? The whole point of indenting C is to make the flow of execution obvious to the reader. Your code goes out of the way to obfuscate this!! Either forget indentation all together:

int main (void)
{
unsigned char keypressed;
MCUCR = (1<<JTD);
MCUCR = (1<<JTD);

DDRB = 0xFF;
DDRD = 0xFF;
Lcd8_Init();
Lcd8_Cmd(0x80);
Lcd8_Write_String("Press the key");
_delay_ms(1200);
Lcd8_Clear();
col_init();
while(1)
{

keypressed = read_key();
Lcd8_Cmd(0x80);
Lcd8_Write_String("Key pressed is :");
Lcd8_Set_Cursor(2,1);
Lcd8_Write_Char(keypressed);

if (keypressed == 0X33)
{
char buffer[8], i=0;
Lcd8_Cmd(0x80);
Lcd8_Write_String("Select a crop:");
while(1)
{
keypressed = read_key();
Lcd8_Set_Cursor(2,1);
Lcd8_Write_Char(keypressed);

if (keypressed == 0X31)
{
Lcd8_Cmd(0x80);
Lcd8_Write_String("Planting date ");

do
{
do 
{
keypressed = read_key();
} while (keypressed == 0XFF);

buffer[i] = keypressed;
i++;

}while(i<8);

buffer[i]='\0';

Lcd8_Write_String(buffer);
}
}
}
}
}

or do it properly...

int main (void)
{
    unsigned char keypressed;
    MCUCR = (1<<JTD);
    MCUCR = (1<<JTD);
    
    DDRB = 0xFF;
    DDRD = 0xFF;
    Lcd8_Init();
    Lcd8_Cmd(0x80);
    Lcd8_Write_String("Press the key");
    _delay_ms(1200);
    Lcd8_Clear();
    col_init();
    while(1)
    {
        
        keypressed = read_key();
        Lcd8_Cmd(0x80);
        Lcd8_Write_String("Key pressed is :");
        Lcd8_Set_Cursor(2,1);
        Lcd8_Write_Char(keypressed);
        
        if (keypressed == 0X33)
        {
            char buffer[8], i=0;
            Lcd8_Cmd(0x80);
            Lcd8_Write_String("Select a crop:");
            while(1)
            {
                keypressed = read_key();
                Lcd8_Set_Cursor(2,1);
                Lcd8_Write_Char(keypressed);
                
                if (keypressed == 0X31)
                {
                    Lcd8_Cmd(0x80);
                    Lcd8_Write_String("Planting date ");
                    
                    do
                    {
                        do
                        {
                            keypressed = read_key();
                        } while (keypressed == 0XFF);
                        
                        buffer[i] = keypressed;
                        i++;
                        
                    }while(i<8);
                    
                    buffer[i]='\0';
                    
                    Lcd8_Write_String(buffer);
                }
            }
        }
    }
}

Normally I would have used the "indent" command in Linux to fix that indentation but as I am using a Windows only machine I actually did that online by pasting your code into:

http://courses.cs.washington.edu...

(hint: make sure the Language radio buttons are set correctly before you start!)

In that case rather than trying to print the whole string of 8 keys using:

Lcd8_Write_String(buffer);

Print what the 8 values you have collected are using:

int n;
for (n=0; n < 8; n++) {
    Lcd8_Num(buffer[i]);
    Lcd8_Write_Char(',');
}

which should show you the numeric value of the 8 bytes in buffer[]

Of course this is assuming your LCD library has functions called Lcd8_Num() and Lcd8_Write_Char() but as "Lcd8_" is quite an unusual name I think I may have found the site that shows that it DOES have these functions.