Wireless Environmental Monitoring Device

This wireless environmental monitoring device is based on the principle of binary Amplitude Shift Keying (2ASK). Under the control of ultra-low-power single-chip microcomputer MSP430F449, the device can detect the temperature an light around it. The detect system consists of monitoring terminal, detecting nodes and coupling coils. In the mode of UART asynchronous communication, the device can realize the function of wireless data transmission with the carrier of 8MHz. Monitoring terminal and detecting nodes are both applied on the same transceiver circuit. The transmitter achieves 2ASK modulation by using the keying method. The receiver achieves 2ASK demodulation by using the envelope detection method. Detection nodes are battery powered. It can preset code, detecting the ambient temperature and light, and then transmit the message automatically. The absolute error of measured temperature is below 2 degrees C, and the absolute error of power consumption is below 0.2W. Monitoring terminal uses one single power supply. It can communication with the detecting nodes directly, and display the node number and the detected information. In the condition of detecting delay is below 2S and detecting range D + D is above 50cm, the supply power of the monitoring terminal <= 0.5W. The whole system has simple circuit, low power consumption and multifunction. (C) 2011 Published by Elsevier Ltd. Selection and/or peer-review under responsibility of [CEIS 2011]