def set_pwm(self, led_num, value):
        """Set PWM value for the specified LED

        :param led_num: LED number (0-15)
        :param value: the 12 bit value (0-4095)
        """
        self.__check_range('led_number', led_num)
        self.__check_range('led_value', value)

        register_low = self.calc_led_register(led_num)

        self.write(register_low, value_low(value))
        self.write(register_low + 1, value_high(value))
Set PWM value for the specified LED

        :param led_num: LED number (0-15)
        :param value: the 12 bit value (0-4095)