codigo funcion

buenas a todos :)

no consigo encontrar el codigo de la funcion propia de arduino "pulsein" para ver que es lo que hace exactamente,

estoy trabajando en linux y he encontrado las librerias que estan en usr/share/arduino/libraries

pero las funciones por defecto de arduino no consigo encontrarlas

alguien me podria informar?

gracias XD

Es esto lo que buscas?

unsigned long pulseIn(uint8_t pin, uint8_t state, unsigned long timeout)
{
    // cache the port and bit of the pin in order to speed up the
    // pulse width measuring loop and achieve finer resolution.  calling
    // digitalRead() instead yields much coarser resolution.
    uint8_t bit = digitalPinToBitMask(pin);
    uint8_t port = digitalPinToPort(pin);
    uint8_t stateMask = (state ? bit : 0);
    unsigned long width = 0; // keep initialization out of time critical area

    // convert the timeout from microseconds to a number of times through
    // the initial loop; it takes 16 clock cycles per iteration.
    unsigned long numloops = 0;
    unsigned long maxloops = microsecondsToClockCycles(timeout) / 16;

    // wait for any previous pulse to end
    while ((*portInputRegister(port) & bit) == stateMask)
        if (numloops++ == maxloops)
            return 0;

    // wait for the pulse to start
    while ((*portInputRegister(port) & bit) != stateMask)
        if (numloops++ == maxloops)
            return 0;

    // wait for the pulse to stop
    while ((*portInputRegister(port) & bit) == stateMask) {
        if (numloops++ == maxloops)
            return 0;
        width++;
    }

    // convert the reading to microseconds. The loop has been determined
    // to be 20 clock cycles long and have about 16 clocks between the edge
    // and the start of the loop. There will be some error introduced by
    // the interrupt handlers.
    return clockCyclesToMicroseconds(width * 21 + 16); 
}

El source para pulseIn() debes de encontrarlo en wiring_pulse.c

perfecto, muchas gracias, era lo que buscaba ;)