Research On Hand-Held Device Of Digital Vortex Flowmeter With Low Power Consumption Based On USB Bus

Usually, industrial field instrumentations need to be set the parameters by serial communication, before being put into use, however because of the change of the field work environment and a large number of parameters, it is not convenient to go on with serial communication. In order to reduce the cost and improve the convenience of modifying parameters, many scholars at home and abroad did a great of researches.Based on the digital vortex flowmeter with low power consumption designed by the flow rate laboratory of Tianjin University, the author started with analysis ofcommunication mode and communication method. And by contrasting the convenience and popularity of communication mode, finally the USB interface was chose to be added to the vortex flowmeter. At the same time, the hardware and software platforms were built to design the hand-held device, which made the use of the vortex more convenient. At the same time, the hand-held device reserved the interface for modifying the parameters with different instrument settings.The main works of this paper are as followed:1.Based on the analysis of USB communication protocol, the USB control chip which was suitable for single-chip microcomputer was selected to the vortex flowmeter , realizing the USB communication of the single-chip microcomputer.2. The hardware platform was designed in this paper. In this project, a further research of the hand-held device based on MSP430 MCU was conducted. Besides, global system power loss was reduced.3. The software platform was designed in this paper. Hierarchical state machineswere used for task scheduling, while the architecture of the software system was designed based on header files, as a result, the readability, reliability and flexibility of the software was improved.4. The menu design of liquid crystal display was designed. Traditionally, the binary tree structure was used for the menu design, while , in this project, one-dimensional array was used in place of the binary tree structure, meeting the design requirements and reducing the share of single-chip resources.5. The change of master and slave function has been completed. The vortex flowmeter plays as the host, when it connects to U disk, while it plays as the slave, when connecting to the hand-held device or the PC. And the hand-held device plays as the holt ,when it connects to the vortex flometer, while it plays as the slave , when connects to the PC.6.The experimental verification has been completed. By adding USB interface for the vortex flowmeter and the design of hand-held device, the test results in the laboratory was satisfactory.The above works illustrated that this hand-held device of the vortex flometer had a good performance in the laboratory, and improve the convenience of the vortex flometer.