PIC 16F877A basic led blinking does not work

Question

It has been quite a while since I haven't done PIC programming.

While trying to run a simple example I have ran into a problem.

#include <pic.h>

int main()
{
    TRISB = 0; // PORTB is output

    PORTB = 0xFF; // All leds are on

    while (1) {} // Loop forever

}

I use PICKit2 command line interface to load to program into the microcontroller.

pk2cmd -PPIC16F877A -Fhelloworld.hex -M PICkit 2 Program Report 1-10-2020, 21:19:44 Device Type: PIC16F877A

Program Succeeded.

You can see the schematics of the circuit here.

I meausured the voltage at the output of RB5 with a multimeter. It was about 300 mV.

Are there any ideas on how to fix this problem. Thanks.

Answer 1

I was able to solve the problem.

It appears that some of my LED's were damaged.

The external clock frequency is set to high speed (HS).

The updated code can be found here.

#include <pic.h>

#ifndef _XTAL_FREQ
// The clock frequency is 16 Mhz
#define _XTAL_FREQ 16000000
#endif

__CONFIG (FOSC_HS & WDTE_OFF & LVP_OFF & CPD_OFF & CP_OFF);

int main()
{
    TRISB = 0; // PORTB is output

    while(1)
    {
        /* RB5 PORTB6 is on */
        PORTB = 0x20;  // b0010 0000

        /* wait for a second */
        __delay_ms(1000);

        /* all leds on PORTB is off */
        PORTB = 0;

        /* wait for a second */
        __delay_ms(1000);
    }
}