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#include <xc.h>

#include "defines.h"

#include "base_PWM.h"

void PWM_Init() {

    // Output pin initially blocked

    PWM_TRIS = 1;

    /* Initialize PWM module */

    PR2 = 0xF9; // 4ms @ 16MHz

    CCP1CONbits.P1M = 0b00; // Single output, P1A modulated only

    CCP1CONbits.CCP1M = 0b1100; // PWM mode, P1A active-high, P1B active-high

    // Idle the output till width is specified

    CCPR1L = 0x00;

    CCP1CONbits.DC1B = 0b00;

    /* Initialize Timer 2 */

    PIR1bits.TMR2IF = 0; // Clear the interrupt flag for Timer 2

    T2CONbits.T2CKPS = 0b11; // Set a prescaler of 64

    T2CONbits.TMR2ON = 1; // Enable the timer

    // Wait for the timer to overflow before enabling output

    while (!PIR1bits.TMR2IF);

    PWM_TRIS = 0;

}

void PWM_Set_Width(int width_us) {

    // Set the pulse duration to the requested width

    int value = width_us / 4;

    CCPR1L = value >> 2;

    CCP1CONbits.DC1B = value;

}