基于单片机的学生签到系统的设计与实现（国外英文资料）.docVIP

基于单片机的学生签到系统的设计与实现（国外英文资料） The design and implementation of the student check-in system based on the single chip microcomputer Student check-in system analysis and design The design of the proposal design is specific Students sign in this design is based on AT89C52 single-chip microcomputer clock system, this system is composed of rf chip, rf card data RC522 ID number, then 51 single chip microcomputer by obtaining ID query entry database to determine which are signed in, at the same time save the clock in record time. Calendar time setting is precise time via PC software for computers, and through a serial port to calendar update to the board system, operation than Settings easy to understand. Also sent via computer software serial command input student information, modify, student information, set the calendar, sets the lower limit on check-in time, commonly used in the market at the same time 12864 LCD display time and clock in the details of the function. Plan 1.2 design overview diagram 1.3 database design 1.3.1 main control chip AT89C52 On this piece of single chip microcomputer AT89C52 chip, integrated the main component of a micro computer, including CPU, memory, and programmable I/O port, timer/counter, the parts connected by internal bus. Here are a few main sections. Figure 1.2 is the basic building block diagram for the AT89C52 single chip machine. 1.3.2 AT89C52 pins VCC: power supply voltage. GND: grounded. P0 port: P0 is a two-way I/O port for eight leak stages, and the 8TTL gate current is absorbed by the foot. When the P1 tube foot is written to 1, it is called high resistance input. P0 can be used for external ROM data, also known as data/address 8. In FLASH programming, the original code input is PO, and when it is being validated, PO outputs the original code, which must be raised outside the PO. P1: the potential two-way universal I / 0. When P1 is put into 1, the upper pull resistance increases, as input, when P1 becomes low power, there is curr