General Data Acquisition And Transmission Sytem Design In Sensing Layer

Data acquisition and transmission is one of the most important function of the sensing layer of Io T(Internet of Things). At present, some dedicated data acquisition and transmission devices are designed to meet particular occasion and certain requirements which restrict their application. If the applied occasion changes a little, the hardware or the software part of the system may changes a lot which may cost a lot of time and energy.A general data acquisition and transmission system is introduced in this dissertation.One structure is based on Ethernet, and the other one is based on Ethernet and CAN bus.The two basic structures can not only be used alone, but also be used when they combined. The type and number of sensors that connect to the system is not constant,which can be added or deleted by PC software dynamically. So, the system can be applied in common occasion.The hardware platform of general data acquisition and transmission system is constructed and several important interface circuits is designed such as CAN bus interface circuits, Ethernet interface circuits, etc. The software platform of the system is constructed based on the hardware platform including the transplantation of Bootloader,Linux kernel and root file system. Some important device driver programs are transplanted such as NAND Flash, CAN bus controller chip, Ethernet controller chip,etc. The application of the general data acquisition and transmission system is designed,and the function of the system is tested. The results of the test show that the system can acquire and transmit data stably.