【正文】 陜西理工學院畢業(yè)設計 第 17 頁共 39 頁 參考文獻 [1]陳煒 . 簡易青少年視力保護器的設計 [J].科技展望 ,2021,33:8789. [2]屏幕視力保護器 [J]. 工業(yè)設計 ,2021,05:6063. [3]李濟安 . 會說話的文具盒 轟動讀者節(jié) [J].現(xiàn)代營銷 (經營版 ),2021,01:45. [4]徐國平 . 智能感控視力保護儀的設計 [D].華中師范大學 ,. [5]張玉鳳 ,李水蓮 . 基于 51 單片機的紅外視力保護儀的設計 [J].電子制作 ,2021,08:712. [6]商瑩 . 視力保護儀的研究與設計 [J].新技術新工藝 ,2021,06:3436. [7]何冰 ,王菊霞 ,蘇變玲 . 基于單片機的視力保護器設計 [J].電子設計工程 ,2021,03:8992. [8]李驍 ,王彬媛 ,王振中 ,劉炳言 ,李昱釗 ,張黔 . 基于 STC89C52 單片機的視力保護器設計 [J]. 電子世界 ,2021,19:160162. [9]張標 . 視力保護器 [J]. 發(fā)明與創(chuàng)新 ,2021,09:2728. [10]盛占石 ,黃賽帥 ,王青青 . 基于 STC89C52 智能計數(shù)控制儀 [J]. 儀表技術與傳感器 ,2021,01:5759. [11]刁宇清 . 基于 PROTEUS的單片機仿真實驗系統(tǒng)研究及應用 [D].西安工業(yè)大學 ,2021,05:2428. [12]趙健 .實用聲光電及無線電遙控電路 300 例 .[J]北京：中國電力出版社， . [13]姚遠 ,毛海莉 ,徐國平 ,吳炎波 . 基于單片機的超聲波測距系統(tǒng)設計 [J]. 高等函授學報 (自然 科學版 ),2021,04:6971. [14]王君 . 根據單片機的超聲測距系統(tǒng)原理設計 [J]. 信息通信 ,2021,03:104105. [15]曾勇 . 基于 單片機的超聲波報警系統(tǒng)設計 [J]. 科技視界 ,2021,09:112114. [16]Rong Pan,Hai Zhao,Jialiang Wang,Dan Liu,Penghua Cai. The Design and Implement of TCP/IP Protocol Cluster on AVR Singlechip[J]. Journal of Software Engineering and Applications,2021,38. 陜西理工學院畢業(yè)設計 第 18 頁共 39 頁 附錄 A 英文文獻 原文 The Introduction of AT89C51 Description The AT89C51 is a lowpower, highperformance CMOS 8bit microputer with 4K bytes of Flash programmable and erasable read only memory (PEROM). The device is manufactured using Atmel’s highdensity nonvolatile memory technology and is patible with the industrystandard MCS51 instruction set. The onchip Flash allows the program memory to be reprogrammed insystem or by a conventional nonvolatile memory programmer. By bining a versatile 8bit CPU with Flash on a monolithic chip, the Atmel AT89C51 is a powerful microputer which provides a highlyflexible and costeffective solution to many embedded control applications. Function characteristic The AT89C51 provides the following standard features: 4K bytes of Flash, 128 bytes of RAM, 32 I/O lines, two 16bit timer/counters, one 5 vector twolevel interrupt architecture, a full duplex serial port, onechip oscillator and clock circuitry. In addition, the AT89C51 is designed with static logic for operation down to zero frequency and supports two software selectable power saving modes. The Idle Mode stops the CPU while allowing the RAM, timer/counters, serial port and interrupt system to continue functioning. The Powerdown Mode saves the RAM contents but freezes the oscillator disabling all other chip functions until the next hardware reset. Pin Description VCC： Supply voltage. GND： Ground. Port 0 Port 0 is an 8bit opendrain bidirectional I/O port. As an output port, each pin can sink eight TTL inputs. When 1s are written to port 0 pins, the pins can be used as highimpedance inputs. Port 0 may also be configured to be the multiplexed address/data bus during accesses to external program and data memory. In this mode P0 has internal Pullup resistor. Port 0 also receives the code bytes during Flash programming, and outputs the code bytes during Program verification. External Pullup resistors are required during Program verification. Port 1 Port 1 is an 8bit bidirectional I/O port with internal Pullup resistors. The Port 1 output buffers can sink/source four TTL inputs. When 1s are written to Port 1 pins they are pulled high by the internal Pullup resistors and can be used as inputs. As inputs, Port 1 pins that are externally being pulled low will source current (IIL) because of the internal Pullup resistors. Port 1 also receives the loworder address bytes during Flash programming and verification. Port 2 Port 2 is an 8bit bidirectional I/O port with internal Pullup resistor. The Port 2 output buffers can sink/source four TTL inputs. When 1s are written to Port 2 pins they are pulled high by the internal Pullup resistor and can be used as inputs. As inputs, Port 2 pins that are externally 陜西理工學院畢業(yè)設計 第 19 頁共 39 頁 being pulled low will source current, because of the internal Pullup resistor. Port 2 emits the highorder address byte during fetches from external program memory and during accesses to external data memory that use 16bit addresses. In this application, it uses strong internal Pullup resistor when emitting 1s. During accesses to external data memory that use 8bit addresses, Port 2 emits the contents of the P2 Special Function Register. Port 2 also receives the highorder address bits and some control signals during Flash programming and verification. Port 3 Port 3 is an 8bit bidirectional I/O port with internal Pullup resistor. The Port 3 output buffers can sink/source four TTL inputs. When 1s are written to Port 3 pins they are pulled high by the internal Pullup resistor and can be used as inputs. As inputs, Port 3 pins that are externally being pulled low will source current (IIL) because of the Pullup resistor. Port 3 also serves the functions of various special features of the AT89C51 as listed below: Port 3 also receives some control signals for Flash programming and verification. RST Reset input. A high on this pin for two machine cycles while the oscillator is running resets the device. ALE/PROG Address Latch Enable output pulse for latching the low byte of the address during accesses to external memory. This pin is also the program pulse input (PROG) during Flash programming. In normal operat。 盡管這次的設計達到了畢設的要求，但覺得這些還是不夠人性化，因為時間關系只能做這么多，如果可以讓這個設計更加完善， 應該讓其在工作的時候若在一定范圍內感應不到人的情況下自動停止計時，當再次感應到人的時候能夠自動開始計時。通過 超聲波原理 輔助學生坐直進而 保護其 視力，簡單方便且不會產生系統(tǒng)穩(wěn)定性方面的問題。 本文探索并實現(xiàn)了 多功能視力保護器 設計的完整過程。在程序中也有延時，有的長，有的短，測距也有一定的誤差，但是影響都不大。 然后加入超聲波測距程序，并調整超聲波的來達到預期的效果。 軟件測試 ： 在 Keil uvision 4 中編寫程序，進行調試 ， 修改語法錯誤。在焊接過程中，要保證每個焊點的連續(xù)焊接時間不超過 10S，因為時間過長會導致元器件過熱而損壞，在焊接電路板的時候，從單片機開始，一部分一部分地焊接并且一定要隨時檢測電路是不是導通的。在檢查前必須分類 ，這樣就可以在出現(xiàn)錯誤時糾錯。 開 始發(fā) 送 超 聲 波等 待 發(fā) 射 超 聲 波計 算 避 障系 統(tǒng) 初 始 化顯 示 結 果 圖 超聲波測距子程序流程圖 陜西理工學