Distributed Temperature Measurement System Design Based On Ethernet

With the development of embedded technology, people put forward network communications requirements. Network communications make embedded system no longer an individual, but part of an overall information technology networks, the technology is widely used in smart devices, information appliances, intelligent management equipment, security monitoring, and other fields.A distributed temperature measurement system based on ethernet is designed. The system is composed by acquisition unit, communication unit and the master host computer. The temperature acquisition unit is responsible for collecting temperature data and sending them to the communication unit, when the communication unit receives the data, it can either send the data to the master host computeror write them to SD card. The communication unit communicates with the temperature acquisition unit by the wirelesswhile communicates with the host computer by ethernet.The paper includes three-parts:system software design, hardware design, and system debugging.The software part of the system includes data acquisition unit and data receipt unit program design, The contents include:data acquisition subroutine, the data sent subroutine, an embedded operating system μC/OS_II,TCP/IP protocol stack of UIP and file system FatFs transplantation, establishing the data sending tasks, the data receiving tasks, data storage tasks, data display tasks and using the message mailbox synchronization between the tasks.Real-time display are achieved by LABVIEW language programing the TCP/IP communication.The hardware of the system includes the choice of the temperature sensor, wireless data transceiver design, SD card interface design, selection of the STM32chip as a control chip, when DS1621completes data acquisition, the master chip sent the data through the RF chip NRF24L01. ENC28J60and NRF24L01compose of the data receiving device.When data reception is complete, the data is written to the SD card and send to a computer by ethernetFinally, though system debugging, the system can complete data acquisition, data transmission, data storage by task scheduling and can communicate properly with the host computer, the host computer can stably show the data by real-time...