Development Of Inductance Sensor Data Acquisition System Based On FPGA

Inductance sensor, with an extra high resolution, high reliability and extremely long campaign life, has been widely applied to the measurement of micro-displacement. In data acquisition system (DAS), conditioning circuit was composed of discrete components, and control circuit adopted microprocessor with limit resources and slow speed. Such is unfavorable to miniaturization and assurance of the Reliability. With the rapid development of integrated circuit, conditioning circuit integrated resolution has appeared, and FPGA is widely used in DAS control circuit because of its rich resources and imbedded controller. This paper takes the development of inductance sensor data acquisition system based on FPGA as the research contents. The specific studies are as follows:This paper briefly introduces the development of inductance sensor and its DAS at home and abroad. On the basis of summarizing the development course and direction of DAS, control core based on FPGA and Nios II soft-core processor is determined.The hardware system of DAS contains analog and digital circuit. The main function of analog circuit is conditioning signal, amplifying-filtering, A/D converter and anti-interference. Digital circuit takes EP1C3 as core, and implements A/D conversion, FIFO buffer, USB interface control logic by using Nios II soft-core processor. System software contains includes USB communication program (firmware and driver) and the application software in PC. This paper makes full use of Nios II soft-core to construct program framework by using C/C++ language Nios II integrated development environment. The driver and host application software are designed in Visual C++ 6.0 and its assistant software DriverStudio and DDK.Finally, experimental results show that DAS basically achieves the design requirements, which lay a good foundation for further practical product development.