Research On HID Dimmable Control System With ZigBee Technology

With the continuous increasing of people's life level and quality, the consumption of resources and energies grow up everyday. The shortage of them attracts more attention of the whole world, and many countries formulate relevant policies to cut down on resources. Nowadays, lamps' network controlling systems mainly use field bus. Such wire communication brings high metal consumption. Wireless Personal Area Network (WPAN) can solve this problem, because it connects devices in the range of 100 meters to establish a network, even join Internet to extend the coverage.ZigBee is a fast-developing wireless communication technology of low rate, low power consumption and short distance, which was published by IEEE 802.15.4 team and ZigBee Alliance in Dec. 2004. It is suitable for industrial control, house intelligent control, etc.Dimmable electronic ballast is meaningful to energy-saving. L6574 is designed as the control chip in high frequency inverter circuit in the ballast, which could adjust the lamp's working frequency in accordance with the reference voltage of operating amplifier in it. The design of the dimmable electronic ballast in wireless network is based on the combination of these two technologies.Firstly, this paper research on ZigBee stack and its layers in different functions and communication frames. Then it analyses the ways and features of three types of topologies in ZigBee networks, and calculates the coverage area and number of devices the wireless network can accept. At last, a proper topology adapted to ballasts outdoors is chosen. Every device uses one RF chip CC2420 which accords with IEEE 802.15.4 standard. This paper describes the processes of establishing a new network and steps of its practical application. The design of the dimming and switching control from coordinator to end device is given. The experimental waveforms verify the practicality of the wireless network.