class DSModulator:
    """A second order delta-sigma modulator"""
    def __init__(self):
        self.reset()

    def reset(self):
        self.integrator1 = 0
        self.integrator2 = 0
        self.output = False

    def step(self, x):
        output = self.output * 2**16
        self.integrator1 += x - output
        self.integrator2 += self.integrator1 - output
        self.output = self.integrator2 >= 2**15
        return self.output