Shift-frequency Signal Acquisition System Based On S3C2440A

China's railway has widely adopted ZPW-2000A none-insulation frequency-shift automatic blocking System. With the accelerating of the speed, frequency-shift signal detection system established based on traditional detection method is facing great challenges in China.This paper proposed a single-chip solution for ZPW-2000A railway frequency-shift signal detection based on the analysis of the spectral characteristics of frequency-shift signal.Firstly, according to Nyquist sampling theorem to determine the appropriate sampling frequency, FFT computation obtained the center frequency of ZPW-2000A. Apply Zoom-FFT algorithm to amplify the frequency-shift signal, in order to increase the resolution of low-frequency detection.Secondly, the above algorithm has been successfully applied on S3C2440A, the ARM processor, realized separation of the main and accessory frequency of ZPW-2000A signal, low-frequency on single-chip processor. This system has been designed as a handheld device, which embeddedμC/OS-Ⅱoperating system, with touch screen LCD. At the same time the system realized the communication with PC using the USB. Test results show that the system can meet the railway frequency shift signal detection accuracy and has high integration and high reliability.Finally, in conclusion summarizes the main tasks of this paper and pointed out the shortcomings and the direction of further work.