Linear array CCD real-time detection data USB synchronous transmission circuit

Abstract

Provided is a linear array CCD real-time detection data USB synchronous transmission circuit. The circuit comprises a main chip PIC18F4550. The main chip PIC18F4550 is provided with a clock by a 20 MHz external passive crystal oscillator, the clock is connected with a thirteenth pin and a fourteenth pin, i.e., OSC1 and OSC2, clock signals, after entering the chip, through five frequency division, are inputted to a PLL (phase-locked loop) by 4 MHz, and the PLL generates a 96 MHz frequency, and through two frequency division, obtains a 48 MHz fixed frequency which is respectively used for a CPU clock and a USB2.0 full-speed communication clock. According to the invention, a PIC18F4550 type single-chip microcomputer serves as a lower computer control core of a linear array CCD real-time detection system, and by use of an integrated USB communication module, a hardware circuit and a firmware program for USB synchronous transmission are designed, so that real-time transmission of frame pixel data to a host computer during linear array CCD real-time detection is realized.

Description

technical field [0001] The invention relates to a USB synchronous transmission circuit, in particular to a line array CCD real-time detection data USB synchronous transmission circuit. Background technique [0002] Compared with unit photoelectric devices, linear array CCD devices have advantages such as high resolution, and are widely used in real-time on-line detection fields such as automation equipment, intelligent instruments and industrial production. Its driving module, A / D conversion of pixel signal and timing control and other functions are realized by the lower computer installed on the industrial production line. Most of the lower computers are built with microcontrollers as the core. In order to improve the detection accuracy of the system, The host computer needs to have strong computing power to complete pixel data aggregation, analysis and processing, and judgment and decision-making capabilities, and considering the real-time nature of detection, solid-state ...

AI Technical Summary

Problems solved by technology

Obviously, the serial communication transmission rate of ordinary single-chip microcomputers cannot meet the requirements of real-time pixel data transmission, while USB (Universal Serial Bus) has the advantages of high transmission rate, good scalability, support for hot plugging and low cost, and some types of single-chip microcomputers With a USB integrated module, it can simultaneously realize the timing control of the lower computer and the high-speed transmission of pixel data, becoming the best choice to solve this problem

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