File content as of revision 4:7cb8986200a7:

#include "mbed.h"
#include "FastPWM.h"
#include "FastIO.h"

#define MODSERIAL_DEFAULT_RX_BUFFER_SIZE 16
#define MODSERIAL_DEFAULT_TX_BUFFER_SIZE 64 
#include "MODSERIAL.h"

static const PinName IMPULSE_SENSOR_PIN = PinName(10);

FastPWM mypwm(PWM_OUT);
FastIn<IMPULSE_SENSOR_PIN> pinImpulseSensorIn;

DigitalOut myled(LED1);

Timer   myTimer;

//------------------------------------
// Hyperterminal configuration
// 9600 bauds, 8-bit data, no parity
//------------------------------------
MODSERIAL pcLink(SERIAL_TX, SERIAL_RX);

static const us_timestamp_t  periodImpSens  = 100000UL;
static const us_timestamp_t  periodLEDBlink = 1000000UL;
static const us_timestamp_t  periodPWMWrite = 10000000UL;

static us_timestamp_t  tStampImpSens  = 0UL;
static us_timestamp_t  tStampLEDBlink = 0UL;
static us_timestamp_t  tStampPWMWrite = 0UL;

static unsigned int uiImpSens = 0U;

int main() {
    unsigned int uiImpSensTemp = 0U;
    int iImpSensLastState = 0;

    pcLink.baud(115200);
    pcLink.format(8, SerialBase::None, 1);
    
    mypwm.period_us(100);
    mypwm.write(0.0);
  
    myTimer.start();
        
    while(1) {
        double dPwmDuty = 0.0;
        
        us_timestamp_t  tStamp;

        tStamp = myTimer.read_high_resolution_us();
        
        if (periodLEDBlink < (tStamp - tStampLEDBlink))
        {
            tStampLEDBlink = tStamp;

            myled = !myled;
        }
        
        if (periodImpSens < (tStamp - tStampImpSens))
        {
            tStampImpSens = tStamp;

            uiImpSens = uiImpSensTemp;
            uiImpSensTemp = 0U;

            pcLink.printf("IMP: %u imp.\n", uiImpSens);
        }
        
        if (periodPWMWrite < (tStamp - tStampPWMWrite))
        {
            tStampPWMWrite = tStamp;

            mypwm.write(dPwmDuty);
            pcLink.printf("PWM: %.2f %%\n", mypwm.read() * 100);
    
            dPwmDuty += 0.1;
            
            if (1.0 < dPwmDuty)
            {
                dPwmDuty = 0.0;
            }
        }
        
        // Impulse sensor
        int iTemp = pinImpulseSensorIn.read();
        if (iTemp != iImpSensLastState)
        {
            iImpSensLastState = iTemp;
            uiImpSensTemp++;
        }
    }
}