A novel system to control LED lighting with a low cost and low power wireless sensor network has been proposed. The method requires the deployment of complementary sensors
with Zigbee radio that generate a PWM signal to control
existing commercial LED drivers, which can significantly
reduce the power consumption of the LED lighting. The use
of a light sensor and a PIR sensor in combination with the
user preferences allows the distributed intelligence to save
energy reducing the light intensity. Because many fixtures of
LED lights are already placed, this solution is also suitable
for retrofitting. Moreover the network is flexible and scalable
due to the Zigbee radio. Experimental results indicate that
the proposed system outperforms the state-of-the-art with
a significant reduction of power consumption and cost for
the single and groups of LED lights using the low power,
scalable WSN. It has been shown that this approach decreases
the power consumption in a real life office application by
more than 55% throughout 6 months (in an unpredictable Irish
weather scenario). The prototypes are ready to be inserted in a
commercial driver to enable wireless capability and distributed
control.