Programming

PIC16F877A-HITECH C-Digital Output & Input

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By Jackson Taylor

Digital Output

1) All pin in the PORTB high

#include<pic.h>
#define _XTAL_FREQ 16000000
void main()
{
TRISB=0;
while(1)
{
PORTB=0xFF;
}
}

2) All pin in the PORTB blinking

#include<pic.h>
#define _XTAL_FREQ 16000000
void main()
{
TRISB=0;
while(1)
{
PORTB=0xFF;
__delay_ms(1000);
PORTB=0;
__delay_ms(1000);
}
}

Digital input

1)input at RB0 and PORTB blinking

#include<pic.h>
#define _XTAL_FREQ 16000000
void main()
{
TRISB=1;
PORTB=0;
while(1)
{
if((PORTB&1)==1)
{
PORTB=0xFF;
__delay_ms(1000);
PORTB=0;
__delay_ms(1000);
}
}
}

2)PULL UP enable on RB0 (3 PROGRAMS WITH SAME O/P AND DIFFERENT LOGIC)

basic steps

set RB0 as input

enable pull up bit(by writing 0 to nRBPU)

check RB0

a)

#include<pic.h>
#define _XTAL_FREQ 16000000
void main()
{
TRISB=1;
PORTB=0;       
nRBPU=0;                                      
while(1)
{
if(RB0==0)
{
PORTB=0xFe;
__delay_ms(1000);
PORTB=0;
__delay_ms(1000);
}
}}

b)

#include<pic.h>
#define _XTAL_FREQ 16000000
void main()
{
TRISB=1;
PORTB=0;       
nRBPU=0;                                      
while(1)
{
if((PORTB &1)== 0)
{
PORTB=0xFe;
__delay_ms(1000);
PORTB=0;
__delay_ms(1000);
}
}
}

c)

#include<pic.h>
#define _XTAL_FREQ 16000000
void main()
{
TRISB=1;
PORTB=0;               
OPTION_REG &=(0<<nRBPU);
while(1)
{
if((PORTB &1)== 0)
{
PORTB=0xFe;
__delay_ms(1000);
PORTB=0;
__delay_ms(1000);
}
}
}

EXTERNAL INTERRUPT at RB0

Basic Steps

1)Enable global interrupt(GIE)

2)Enable external interrupt (INTE)

3)select interrupt edge (INTEDG)

4)clear INTF flag in your interrupt service routine

#include<pic.h>
#define _XTAL_FREQ 16000000
void main()
{
GIE=1;
INTE=1;
TRISB=1;
PORTB=0;                           
while(1)
{
if((PORTB &1)== 0)
{
PORTB=0xFe;
__delay_ms(1000);
PORTB=0;
__delay_ms(1000);
}
}
}
void interrupt jimmy(void)
{
INTF=0;
PORTB=0XF;
__delay_ms(1000);
PORTB=0;
__delay_ms(1000);
}

Additional Example

#include<pic.h>
#define _XTAL_FREQ 16000000
void main()
{
TRISB=0;
while(1)
{
PORTB=0xFF;
}
}

2) All pin in the PORTB blinking

#include<pic.h>
#define _XTAL_FREQ 16000000
void main()
{
TRISB=0;
while(1)
{
PORTB=0xFF;
__delay_ms(1000);
PORTB=0;
__delay_ms(1000);
}
}

Digital input

1)input at RB0 and PORTB blinking

#include<pic.h>
#define _XTAL_FREQ 16000000
void main()
{
TRISB=1;
PORTB=0;
while(1)
{
if((PORTB&1)==1)
{
PORTB=0xFF;
__delay_ms(1000);
PORTB=0;
__delay_ms(1000);
}
}
}

2)PULL UP enable on RB0 (3 PROGRAMS WITH SAME O/P AND DIFFERENT LOGIC)

basic steps

set RB0 as input

enable pull up bit(by writing 0 to nRBPU)

check RB0

a)

#include<pic.h>
#define _XTAL_FREQ 16000000
void main()
{
TRISB=1;
PORTB=0;       
nRBPU=0;                                      
while(1)
{
if(RB0==0)
{
PORTB=0xFe;
__delay_ms(1000);
PORTB=0;
__delay_ms(1000);
}
}}

b)

#include<pic.h>
#define _XTAL_FREQ 16000000
void main()
{
TRISB=1;
PORTB=0;       
nRBPU=0;                                      
while(1)
{
if((PORTB &1)== 0)
{
PORTB=0xFe;
__delay_ms(1000);
PORTB=0;
__delay_ms(1000);
}
}
}

c)

#include<pic.h>
#define _XTAL_FREQ 16000000
void main()
{
TRISB=1;
PORTB=0;               
OPTION_REG &=(0<<nRBPU);
while(1)
{
if((PORTB &1)== 0)
{
PORTB=0xFe;
__delay_ms(1000);
PORTB=0;
__delay_ms(1000);
}
}
}
}

EXTERNAL INTERRUPT at RB0

Basic Steps

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1)Enable global interrupt(GIE)

2)Enable external interrupt (INTE)

3)select interrupt edge (INTEDG)

4)clear INTF flag in your interrupt service routine

#include<pic.h>
#define _XTAL_FREQ 16000000
void main()
{
GIE=1;
INTE=1;
TRISB=1;
PORTB=0;                           
while(1)
{
if((PORTB &1)== 0)
{
PORTB=0xFe;
__delay_ms(1000);
PORTB=0;
__delay_ms(1000);
}
}
}
void interrupt jimmy(void)
{
INTF=0;
PORTB=0XF;
__delay_ms(1000);
PORTB=0;
__delay_ms(1000);
}

Additional Example

#include<pic.h>
#define _XTAL_FREQ 16000000
void main()
{
TRISB=1;
PORTB=0;
while(1)
{
if((PORTB&1)==1)
{
PORTB=0xFF;
__delay_ms(1000);
PORTB=0;
__delay_ms(1000);
}
}
}

2)PULL UP enable on RB0 (3 PROGRAMS WITH SAME O/P AND DIFFERENT LOGIC)

basic steps

set RB0 as input

enable pull up bit(by writing 0 to nRBPU)

check RB0

a)

#include<pic.h>
#define _XTAL_FREQ 16000000
void main()
{
TRISB=1;
PORTB=0;       
nRBPU=0;                                      
while(1)
{
if(RB0==0)
{
PORTB=0xFe;
__delay_ms(1000);
PORTB=0;
__delay_ms(1000);
}
}}

b)

#include<pic.h>
#define _XTAL_FREQ 16000000
void main()
{
TRISB=1;
PORTB=0;       
nRBPU=0;                                      
while(1)
{
if((PORTB &1)== 0)
{
PORTB=0xFe;
__delay_ms(1000);
PORTB=0;
__delay_ms(1000);
}
}
}

c)

#include<pic.h>
#define _XTAL_FREQ 16000000
void main()
{
TRISB=1;
PORTB=0;               
OPTION_REG &=(0<<nRBPU);
while(1)
{
if((PORTB &1)== 0)
{
PORTB=0xFe;
__delay_ms(1000);
PORTB=0;
__delay_ms(1000);
}
}
}

Interrupt Example

#include<pic.h>
#define _XTAL_FREQ 16000000
void main()
{
GIE=1;
INTE=1;
TRISB=1;
PORTB=0;                           
while(1)
{
if((PORTB &1)== 0)
{
PORTB=0xFe;
__delay_ms(1000);
PORTB=0;
__delay_ms(1000);
}
}
}
void interrupt jimmy(void)
{
INTF=0;
PORTB=0XF;
__delay_ms(1000);
PORTB=0;
__delay_ms(1000);
}
See also
BLINKING USING DSPIC30F2010 USING MIKRO C

PIC16F877A-HITECH C- ADC ADC

PIC16F877A-HITECH C- EEPROM

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