Development of a Remote Temperature Monitoring System for Bulk Vegetables

Abstract

A remote temperature monitoring device, consisting of a probe, transmitter and receiver, was developed for long-term wireless monitoring of temperatures in bulk vegetables storages. The system utilizes microprocessor technology to time the actuation of data sensing, digitize the data, generate an identifier and transmit the data to a base station receiver. Two custom designed microprocessor boards and a commercially available receiver and transmitter were incorporated into the design. The temperature transmitter is a completely self-contained unit enclosed in ABS tubing to withstand harsh treatment. The transmitter has switch selectable coding to uniquely identify its output to the receiver and to set its transmissions from once per hour to once per 24 h. To conserve power, a maximum transmission time of one second is used with the transmitter remaining in a stand-by mode for the remainder of the time. The receiver is capable of receiving the coded transmissions from 20 transmitters.