Set pwm values on the controlled pins.

        :param raw_values: Raw values to set (0-255).

def _set_pwm(self, raw_values):
        """
        Set pwm values on the controlled pins.

        :param raw_values: Raw values to set (0-255).
        """
        for i in range(len(self._pins)):
            self._pi.set_PWM_dutycycle(self._pins[i], raw_values[i])