设计说明书 基于单片机的pm2.5值检测仪的设计.pdfVIP

前言2 第1 3 第1.1 节 课题背景 3 第1.2 节 国内外P 2.5 值现状及发展趋势 3 第1.3 节 本课题主要工作 4 第2 5 第2.1 节 总体设计选择方案 5 第2.2 节 开发语言选择 5 第2.3 节 传感器选择 6 第2.4 节 CU 选择7 第3 8 第3.1 节 硬件设计 8 第3.2 节 软件设计 11 第4 15 第4.1 节 测试条件 15 第4.2 节 测试过程 15 第4.3 节 测试数据 16 第4.4 节 测试分析 16 17 17 18 附录1：实物照片说明19 附录2：部分源程序20 - i - 【摘要】：本论文基于单片机的原理开发的pm2.5 值检测仪。该仪器通过集合单片 机的控制技术和传感技术相结合的一套设备。传感器接收pm2.5 的浓度信息通过AD 采 样转换由单片机进行读取最后由LCD 屏幕的实时数据体现形成的一套系统，使人们能简 单清晰实时的了解本地的pm2.5 值的情况。 【关键词】：单片机，pm2.5，传感器； [Abstract] : Deploying IP telephony or oice o er IP (VoIP) is a maj or and challenging task for data network researchers and designers. This paper outlines guidelines and a step-by-step methodology on how VoIP can be deployed successfully. The methodology can be used to assess the support and readiness of an existing network. Prior to the purchase and deployment of VoIP equipment, the methodology predicts the number of VoIP calls that can be sustained by an existing network while satisfying QoS requirements of all network ser ices and lea ing adequate capacity for future growth. As a case study, we apply the methodology steps on a typical network of a small enterprise. We utilize both analysis and simulation to in estigate throughput and delay bounds. Our analysis is based on queuing theory, and OPNET is used for simulation. Results obtained from analysis and simulation are in line and gi e a close match. In addition, the paper discusses many design and engineering issues. These issues include characteristics of VoIP traffic and QoS requirements, VoIP flow and call distribution, defining future growth capacity, and measurement and impact of background traffic. [Key words]:Network Design ，Network Manag