PWM の確認:mbed

main.cpp

#include "mbed.h"

PwmOut pin21(p21);
Serial pc(USBTX, USBRX); // tx, rx
DigitalIn dIn(p20);

int main()
{

    //pc.baud(115200);          //921600
    //pin21.pulsewidth_us(10);  //パルス幅0.08us
    //pin21.period_ms(0.1);     //Pwm の周期を100[mS]に設定  //pwm繰り返し周期＝1ms　=>　周期=1kHz
    pin21.write(0.5f);          //デューティサイクル

    Timer timer;
    timer.start();

    int iMicroSec_prev = timer.read_us();
    int iState_prev = NULL;
    while (1) {
        int iState = dIn;       //High or Low

        if( iState != iState_prev ) {
            iState_prev = iState;
            int iMicroSec = timer.read_us();
            pc.printf( "%d, ", iMicroSec - iMicroSec_prev );
            iMicroSec_prev = iMicroSec;
        }
    }

}