Design Of Real-time Experimental Data Wireless Transmission System In Teaching Lab

Abstract:Experimental teaching is an important part in colleges’teaching work. Based on the researches on traditional classroom-experimental-teaching, this paper summarizes its disadvantages and combines with the mature science technology in nowadays in order to design a system of real-time experimental data wireless transmission in teaching labs. The purpose of the system is to improve the interaction between the experiment teacher and students, to average the guidance of the experiment teacher on every student, and finally to get better teaching effect.The design of the system contains these contents as follow:research on experiment lesson teaching sequence, construct the function and hardware structure of the system, design how the data deliver in the master and slave machines, design how the data transmit between the master and slave machines, customize the wireless communication protocol, handle the experiment data formats, design the control interface in PC. Among the contents above, the designs of data transmitting at real time and control interface are the basics to realize the function of the system.The system uses RF4432radio frequency module to receive and send wireless data, selects AVR Maga16single chip as the micro-controller to control the process of wireless communication. The master machine plays the role as the control part in the system, consisting of a host AVR、a RF module and the control interface, and it can exchange data wirelessly with the slave machine in the different steps of experiment lesson teaching sequence. The slave machine can provide the students with experiment equipment, consisting of a guest AVR、a RF module、a PS/2keyboard and the equipment related to experiment. It also can help them input their school identity number, acquire and store experiment data and then return the data to the master machine. As a key design, the system realized how the data deliver in or between the master and slave machine. It includes:establish a unified interface and electric level switching circuit to deliver data between the host AVR and PC, use SPI bus to exchange data between AVR and RF module and realize to control RF module, combine with the lesson teaching sequence to convert experimental data from decimal system to hexadecimal and customize a set of simple, stable and effective wireless protocol to realize the point-to-point data wireless communication, design a time division communication scheme to make the master machine establish communication connection in turn with all the slave machines that realizes point-to-multipoint data wireless communication. According to the real situation of experiment teaching, the system designed a simplified and intuitive control interface so that the basic need of the experiment teacher’s for lesson teaching sequence can be satisfied.By applying the system in Millikan Oil Drop Experiment, imitating the real lesson of numbers of students doing the experiment at the same time, debugging the designs of the system, finding problems, solving problems, the system has been improved constantly.The final running result shows that the system can save the limited energy of experiment teacher’s, improve the teaching efficiency and interaction between the teacher and students, and gain excellent teaching effect.