PIC Interface – PWM

Functions

• pwm_init()
• pwm_dutycycle(unsigned int duty)

Example : Generate predefined PWM using four buttons

Code

• Define Port-B as input and RB0, RB1, RB2 and RB3 used as button input
• Generate PWM using PWM functions

Note  :  UN-command the line depend on your preferred compiler.

//www.ArunEworld.com/embedded/microchip/pic_mcu/
#include<pic.h> // for Hi-Tech Compiler

#define _XTAL_FREQ 4000000

//short currduty1=16;
void init()
{
    PORTB=0X00;
    TRISB=0X0f;
}

void pwm_dutycycle(unsigned int duty)
{
    CCPR1L=duty;
    CCP1CON&=0xCF;
    CCP1CON=(CCP1CON|(0X30&(duty<<4)));
}

void pwm_init()
{
    TRISC=0X00;
    CCP1CON=0X0C;
    PR2=96;
    TMR2=0;
    T2CON=0x7B;
    pwm_dutycycle(0);
    T2CON=0X7F;
}

void delay(unsigned int de) {   while(de--);    }

void main()
{
    pwm_init();
    while(1)
    {
        if(RB0) {   /*delay(100);*/ pwm_dutycycle(0);   }
        if(RB1) {   /*delay(100);*/ pwm_dutycycle(64);  }
        if(RB2) {   /*delay(100);*/ pwm_dutycycle(128); }
        if(RB3) {   /*delay(100);*/ pwm_dutycycle(255); }
    }   
} 

Result :

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