Run program directly with MPLAB X(PIC16F628A)

Question

I want to blink LED with PIC16F628A and run it directly with the button make and program device main project of MPLAB X. to programing the PIC I did simple wiring shown in this tutorial without using any resistor (just wiring).

To blinking the LED I just wired RA0 ---> resistor ---> LED ---> ground but nothing works.

Should I remove some wires after programming the PIC or add something?

code :

#include<htc.h>
#include <pic.h>
#include <pic16f628a.h>
// Config word
__CONFIG(FOSC_INTOSCIO & WDTE_OFF & PWRTE_ON & CP_OFF);
#define LED  RA0
#define _XTAL_FREQ   4000000
void main()
{   
        TRISA0 = 0;                // Make RA0 pin output
        LED    = 0;
        CMCON = 0x07;
        // Make RA0 low
    while(1)
    {
        __delay_ms(1000);       // Half sec delay
        LED = 0;               // LED off
        __delay_ms(1000);       // Half sec delay
        LED = 1;               // LED on
    }
}

MPLAB X output

BUILD SUCCESSFUL (total time: 5s)
Loading code from C:/Users/makhlouf/MPLABXProjects/blink.X/dist/default/production/blink.X.production.hex...
Loading completed
Connecting to programmer...
Programming target...
Programming completed
Running target...

Answer 1

Check your wiring, it looks like you've plugged in the PICkit connector backwards on the breadboard.

Please read the documentation more carefully in the future.

Answer 2

A decoupling capacitor between Vcc and Gnd is missing.

Every time, but even more when working with a breadboard, decoupling caps are necessary.

"What is a decoupling cap"

This may be the cause of strange behaviors of your PIC.

Answer 3

Your code sets the PIC to use MCLR reset but you have nothing pulling you MCLR up to vdd. AFAIK the PICkit2 wont pull it up to vdd but will simply release it. You can add an external resistor pulling your MCLR to Vdd or you can try your code with:

--- __CONFIG(FOSC_INTOSCIO & WDTE_OFF & PWRTE_ON & CP_OFF);
+++ __CONFIG( FOSC_INTOSCIO & WDTE_OFF & PWRTE_ON & CP_OFF & MCLRE_OFF );

I have to point out, even though it may seem basic to some, that LEDs cannot work in reverse, if you are not 100% certain that you have the polarity correct, try reversing the LED (very few LEDs have maximum reverse voltages lower then 5V so this should not be able to damage the LED or the PIC).

Also, dont forget to power your circuit. You have to explicitly tell the PICkit (especially the PICkit3) to power the host circuit otherwise it will assume the circuit has it`s own power supply and it will not feed power to your circuit.

In the PICKit2 interface (your image):

1. check the "VDD PICKit2" - "ON" box to instruct the pickit to supply power to your circuit.

In the MPLABX interface:

1. right click on your project
2. click properties
3. in the tree on the left of the properties window (titled categories), click PICkit 2
4. Uncheck the "Use target power always" box