Study Of Linear-CCD Data Acquisition System Based On ARM

Charge Coupled Devices (CCD) is a photoelectric device with high performance, which is widely applied in many areas, including astronomical imaging, entertainment and manufacturing, etc. The geometrical measure with CCD has an advantage on achieving high accuracy, dynamic detection and non-contact measurement.At present, majority of data acquisition systems adopt the image sensor. The video images are sampled by the real time data acquisition card before sent to the computer to process. The outputs of the camera are analog video signals, and the pixel points of the image sensor are difficult to synchronize with the acquisition card. Therefore the images have low quality, and the resolution is limited. In addition, these equipments often exist as the inserted cards, which have limitations in high cost and complex structure. Due to above problems, few products satisfy the high resolution and portable application requirements on imaging measurement. Using the PXA271 as the core processor, a new kind of real-time data acquisition system based on 32bits embedded ARM processor is put forward.The focus of this dissertation research is to develop the hardware of linear-CCD data acquisition system based on ARM processor, and the related software to support the system. The principle of linear CCD and the scheme of whole system are introduced firstly in the dissertation. The system comprises three modules: the first is the CCD driver module, which controlled with CPLD. Programming the CPLD to produce CCD driving pulses and synchronized communication signals. After preprocessing, the output video signals are transmitted into high resolution ADC module, in which they are converted into digital signals, and then processed in ARM processing module.Finaly, the debug process of the unit circuit is introduced in proper sequence. Compiling and silulating the system operation software. The experiment results are presented and analyzed.