Timer

Hi,
I am trying to write a simple program with Timer 0 using C 18 compiler. Please have a look at the following code and the following error code and let me know where i am going wrong.

#include <p18f4520.h>
#include <timers.h>
#define DELAY 16000

void mian (void)
{
TRISC = 0x00;
T0CON = 0b11000111;

while(1)
{
PORTC =0xFF;
TMR0 = 0;

while ( TMR0 < DELAY)
{
}

PORTC =0x00;
TMR0 = 0;

while ( TMR0 < DELAY)
{
}
}
} // end

the following are the build errors

D:\PIC Projects\Loops2\LOOPS2.C:15:Error [1105] symbol 'TMR0' has not been defined
D:\PIC Projects\Loops2\LOOPS2.C:15:Error [1101] lvalue required

Please help me on this.

regards,
G.Nathan

mrgobis said:

Hi,
I am trying to write a simple program with Timer 0 using C 18 compiler. Please have a look at the following code and the following error code and let me know where i am going wrong.

Code:

#include <p18f4520.h>
#include <timers.h>
#define DELAY 16000

void mian (void)       <--------- Spelling Error -----------
{
TRISC = 0x00;
T0CON = 0b11000111;

while(1)
{
	PORTC =0xFF;
	TMR0 = 0;

	while ( TMR0 < DELAY)
	{
	}

	PORTC =0x00;
	TMR0 = 0;

	while ( TMR0 < DELAY)
	{
	}
}
} // end

the following are the build errors

D:\PIC Projects\Loops2\LOOPS2.C:15:Error [1105] symbol 'TMR0' has not been defined
D:\PIC Projects\Loops2\LOOPS2.C:15:Error [1101] lvalue required

Please help me on this.

regards,
G.Nathan

Click to expand...

Do you have to OPEN and CONFIG the timer with OpenTimer0 ??
MPLAB C18 Lib manual pg 58.

I am looking at the timer stuff myself.

TIMER O with PIC C 18

Hi,

Thanks for spotting the spelling error, i have read document on C18 Library. i am not sure how to open the timer and configure it. I have also tried many time. Please find the code below and please tell me where do i have to open the timer and configure.

#include <p18f4520.h>
#include <timers.h>
#define DELAY 160

void main (void)
{
TRISC = 0x00;
OpenTimer0( TIMER_INT_OFF & T0_8BIT & T0_SOURCE_INT & T0_PS_1_32 );

while(1)
{
PORTC =0xFF;
TMR = 0;

while ( TMR0 < DELAY)
{
}

PORTC =0x00;
TMR0 = 0;

while ( TMR0 < DELAY)
{
}
}
} // end code

following are the error message, It says TMR0 is not difined. Can some body tell me how to define the TMR0. I am sure i am making a school boy error here

D:\PIC Projects\Loops2\LOOPS2.C:13:Error [1105] symbol 'TMR' has not been defined
D:\PIC Projects\Loops2\LOOPS2.C:13:Error [1101] lvalue required

regards,
G.Nathan

The error states that TMR is not defined and I think you are reading it as TMR0. Change the line TMR=0 to TMR0=0 and all will be well. As you suspected, a schoolboy error and one I'm sure you won't repeat.

Mike.

Good all! i've been trying to design a code in assembly for 16f84a for digital clock, pls is there any body that can help me out there am new in assembly.