import time

class HCSR04:
    def __init__(self, pinTrigger, pinEcho):
        self.f = open('hcsr04.dat','r')

    def __iter__(self):
        for dada in self.f:
            yield float(dada)

    def llegeix(self):
        return float(self.f.readline())

    def tanca(self):
        self.f.close()