Usb Ccd Data Acquisition System

As the development of photo-electronics and the semiconductor technology, the photoelectric apparatus develops rapidly and has been applied widely in many domains of economy. Among them, CCD can transform light to electricity, store information and delay time, etc. It also has the merits such as small size, light weight, lower power, low noise, good linearity, high sensitivity, large dynamic range, stable performance and strong scanning-self ability. These are the reasons that CCD is widely used in sensing image, measuring shape of object, project examination, storing and processing information.A CCD data acquisition system based on USB is designed in this paper. Firstly, the work principle and main features of CCD are presented briefly. Then the work principle of main chip and function circuit design are analyzed detailedly. The application software and firmware supporting every function circuit working are also programmed in this project.The main chips used in this system include array CCD sensor TCD1209D, special-purpose image processing chip AD9822, and ARM7 micro processing chip LPC2146. In the design process, each chip's outstanding features have been used adequately. The driving wave of CCD programmed on PC is outputted through GPIO of LPC2146 to driver TCD1209D. It is simply to design driving circuit, and the driving wave can be modified momentarily. In data acquisition circuit, AD9822 is a special-purpose image processing chip for CCD. Before the signal is transformed from analog to digital accurately, optimization and pre-process are done to make the data acquisition system more stable and more reliable.USB2.0 interface is used to transit data. The characteristic of the USB are PNP, easy to expand, etc. The characteristics of LPC2146 USB controller are high speed, stable. These characteristics make the transition of data much higher in speed and more flexible in comparison to the traditional interface.Finally, the PCB of system circuit is finished. Every module of the system is debugged, and an experiment result is given out.