In this project we will learn how to animate LED up to down using PIC Microcontroller. Here I we are using PIC16F877A Microcontroller and MikroC pro for PIC compiler for this project. You con watch the following video or read the written tutorial below. 

I/O pin of PIC16F877A microcontroller

PIC16F877A Microcontroller has A0-A7, B0-B7, C0-C7, D0-D7 and E0-E2 input/output port. Some pins for these I/O port are multiplex with an alternative function for the peripheral feature on the device. In general, when a peripheral is enable, that pin may not used as a general purpose I/O pin.

In this project we will use PORTB for blinking LED. For  controlling PORTB it has two register TRISB and PORTB.
The TRISB Register controls the direction of Input/Output port. Here PORTB is 8bit wide, bi-directional port. The corresponding data direction register is TRISB. Setting a TRISB bit (= 1) will make the corresponding PORTB pin an Input. Clearing a TRISB bit (=0) will make the corresponding PORTB pin an Output. 

void main() {
     TRISB = 0X00;           //PORTB is Output
     PORTB = 0X00;           //Clear PORTB
     while(1){
          PORTB = 128;
          delay_ms(500);             //500ms delay
          PORTB = 64;
          delay_ms(500);
          PORTB = 32;
          delay_ms(500);
          PORTB = 16;
          delay_ms(500);
          PORTB = 8;
          delay_ms(500);
          PORTB = 4;
          delay_ms(500);
          PORTB =2;
          delay_ms(500);
          PORTB = 1;
          delay_ms(500);
      }

}

Code Explain

Here I am use MikroC pro for PIC compiler for code editing. In void main function I define PORTB is output by clearing TRISB register. Then we clear the PORTB register. In next, here I am use while loop for continues program execution and blinking LEDs. 

PORTB output value

Circuit Diagram

Component List

1. PIC16F877A Microcontroller
2. Crystal(8MHz)
3. Push button
4. led 3mm(8)
5. Resister: 10k ,100R
6. Breadboard
7. Jumper Wire
8. 5V DC Supplay

Download free source code 

 download