"密码防盗键盘设计与应用研究"

" This document, titled "Single Chip Microcontroller Innovative Design," details the design and implementation of a new type of password-protected keyboard based on the AVR mega16 microcontroller. The keyboard is capable of dynamically displaying the position of the keys and their corresponding numbers through LED seven-segment displays. The microcontroller scans each key position to determine input. The purpose of this project is to create a cost-effective, simple, and easily executable solution to prevent theft of passwords through devices such as cameras. The key positions on the keyboard are randomized, and the display of numbers on the keys changes each time a withdrawal is made. This randomization prevents criminals from determining the password by capturing the keyboard with a camera, solving the problem of theft through cameras. The hardware design is based on the AVR microcontroller, with peripheral devices including 12 seven-segment displays, two ULN2003 chips, one 74LS248 chip, as well as resistors and a power supply. The document includes hardware circuit diagrams and explanations, as well as hardware units and their functions. The software part describes the basic idea, program flowchart, and code, detailing the implementation of the randomization and display of key positions and numbers through the seven-segment displays. In summary, the project has achieved the goal of creating a low-cost and effective solution to prevent theft of passwords through devices such as cameras. The project's technical features and innovations are highlighted, and potential applications and future developments are discussed. The report also includes personal reflections on the project and references for further reading. This document serves as a comprehensive guide to the design and implementation of the password-protected keyboard using a single chip microcontroller.