如何编程UC来反转马达

大家好，我是PIC单片机的新手，需要一些帮助。我试着在网上寻找，但我只能找到PWM速度控制。我用的是PIC18F26K22。我使用ECP来控制RB2和RC2上的增强型PWM。我把我的马达连接到那些引脚上，我需要弄清楚如何编程UC来反转马达。这是我的代码：谢谢。



      以下为原文

    Hello,

I am new to pic microcontrollers and I need some help. I tried looking online but I could only find PWM speed control.
I am using a PIC18F26K22. I am using the eccp to control the enhanced PWM on RB2 and RC2. I connected my motor to those pins and I need to figure out how to program the uC to run the motor in reverse.
Here is my code so far:

void CleanStep() {
    DisUSR = ultrasonic(1); //get distance from ultrasonic sensor 1
    DisUSL = ultrasonic(2); //get distance from ultrasonic sensor 2
   uint16_t dutycycle = 638; //62.5%
    while (1) {
        while (DisUSR > 1) {     //keep going Right till the distance from obstacle is 1cm
            PORTBbits.RB2 = 0;  //is it right to set the pins to LOW before running the PWM?
            PORTCbits.RC2 = 0;
            dutycycle = 638;
            EPWM1_LoadDutyValue(dutycycle);  //Set the speed at 62.5%
            DisUSR = ultrasonic(1);
        }
        dutycycle = 0;
        EPWM1_LoadDutyValue(dutycycle);  //set speed to 0
        PORTBbits.RB2 = 0;  //also is it right to set the pins to LOW after running the PWM?
        PORTCbits.RC2 = 0;

        while (DisUSL > 1) {   //keep going Left till the distance from obstacle is 1cm
            PORTBbits.RB2 = 0;
            PORTCbits.RC2 = 0;
            dutycycle = 638;
            EPWM1_LoadDutyValue(dutycycle);
            DisUSR = ultrasonic(1);
        }
        dutycycle = 0;
        PORTBbits.RB2 = 0;
        PORTCbits.RC2 = 0;
    }
}

Thank you