87 Temperature and Humidity Control System Design for Grain Science and Technology Logistics Center

This paper put forward a granary temperature and humidity control system of hierarchical structure, which constitutes of digital temperature and humidity information acquisition nodes, the touch screen for on-site monitoring, GPRS wireless data transmission module and the PC-based remote monitoring center. The paper also describes the functions of major parts, the selection and application of the touch screen and GPRS module, the circuit design for measurement and control nodes based on SHT71 and STC single-chip that integrate temperature and humidity sensors, software development and host computer configuration.