Wireless Data Acquisition System Of SAW Oscillator Based On The WIFI

In order to accurately collect the data of the surface acoustic wave(SAW) oscillator in real-time, and achieve the remote monitoring, data analysis and preservation, the signal wireless fidelity(WIFI) technology is incorporated into the SAW oscillator, and the wireless data acquisition system of the SAW oscillator based on the WIFI is proposed.The system consists of the oscillator output signal module, the signal conditioning module, the processor module and the wireless processing module. The oscillator output signal module consists of the dual SAW oscillator and the mixer. The wireless processing module consists of the WIFI module and the receiving terminal. In order to improve the frequency stability of the oscillator, the SAW device of 101.76 MHz center frequency and low insertion loss is adopted. The mixed SAW oscillator signal is converted into the lo w frequency square wave signal by the signal conditioning circuit. Based on the software design of the upper computer and the lower computer, the collected signal is sent to the receiving terminal wirelessly by the WIFI module. The frequency measurement, the display and the serial communication of the WIFI are realized. Based on the C# and the Windows system, the acquisition, the dynamic display, the analysis and the preservation of the data are realized.The output of the dual SAW oscillator is tested. The two outputs are the stable sine wave. The frequency of oscillator 1 is 96.28 MHz and the other is 96.75 MHz. The output of the mixer is 470 KHz. The structure and performance of the wireless data acquisition system of the SAW oscillator based on the WIFI is validated and tested with the output frequency range from 100 KHz to 500 KHz by changing the inductance value. Experimental results show that the signal can be collected, transmitted and received wirelessly within the test range. The average absolute error with input signal and the received signal is about 0.843 KHz, and the maximum relative error is about 0.51%. The effective acquisition range is about 100 m in the barrier-free environment and about 50 m in the obstacle environment.