At present, most attendance systems are magnetic card attendance systems. Such systems not only have slow sign in speed, but also cause certain cost and waste of terminal equipment and magnetic card; Fingerprint attendance, face recognition attendance, retinal attendance and other new generation attendance technologies greatly improve the efficiency and accuracy of attendance, but this kind of attendance machine has high cost and troublesome operation. The above types all adopt the passive attendance mechanism. The development of science and technology and the acceleration of the pace of life have brought new challenges to the passive attendance method. The mobile phone Bluetooth attendance machine is designed for the shortcomings of the above attendance machines. Using the mobile phone Bluetooth attendance machine can make it easy for personnel to sign in after passing.
Overall hardware design of the system
The attendance machine system is mainly composed of the following five parts: stm32f103rbt6 microprocessor based on Cortex-M3 core is the core control device, which is mainly responsible for the work and data exchange of each part of the control system; The Bluetooth module is used to search the mobile phone Bluetooth device and send the found mobile phone Bluetooth device address to the microprocessor stm32f103rbt 6 through asynchronous serial communication; Syn6288 voice chip realizes data transmission through UART interface and realizes voice broadcasting of “expected” and “actual” people; Nokia5110 LCD displays the attendance results, and the microprocessor sends the attendance results to the display screen through SPI1 interface for display; The SD card / USB flash disk stores the user information. The microprocessor sends the data to the SD card / USB flash disk through the SPI2 interface, and then obtains the information of the signin by reading the SD card / USB flash disk.
Bluetooth module and peripheral circuit design
The Bluetooth module used in the system adopts hc-05 chip produced by Guangzhou Huicheng Information Technology Co., Ltd. Hc-05 is a civil grade, supports most current mobile Bluetooth devices, and is upward compatible with other higher protocols. The module has the advantages of high integration, good stability, low power consumption and few peripheral circuits, which fully meets the needs of the system. The figure is the peripheral circuit of Bluetooth module. Including status_ Out is the output status indicator pin. D1 will flash during attendance, indicating that the Bluetooth module works normally; Mod pin is the Bluetooth at mode selection pin; RXD and TXD are serial communication interfaces to realize serial communication function.