光电读卡机可行性设计

光电读卡机由上下位机两部分组成。下位机是反射式光电传感器作为答题卡信息采集工具，辨别出答题卡上相应的答案是否被涂黑。传感器输出的信号经电压比较器调理变为比较规则的信号送至微控制器，进行简单处理，把获取的信息变成选择题答案的形式暂存起来。每读完一张卡，把单片机暂存的数据通过串口通讯RS -22发送到上位机。然后，由基于虚拟仪器开发平台Labview的评分系统对读取的答案数据与标准答案比对，得出考生最终得分，并对所有考生的成绩进行相关处理和存储。

Photoelectric reader feasibility design

Software and hardware composition principle of photoelectric card reading system are introduced ,the system consists of two parts ,the lower machine .The machine is a reflection type photoelectric sensor as the answer card information collection tools ,identify the answer sheet on the corresponding answer is black .The output signal from the sensor through a voltage comparator conditioning into signal comparison rules and sent to the micro controller ,simple processing ,to obtain information to select storing the answers in the form ,each read a card ,the SCM temporary data sent to the host computer through the RS-22 serial communication ,then the score system of virtual instrument development platform based on Labview to answer read data with the standard answer alignment ,the candidates final score ,and for all the results of the candidates were related to the processing and storage .