基于单片机的便捷式车载温湿度监测系统的设计与实现

Design and Realization of the Portable Temperature and Humidity Monitoring System for Vehicles Based on Embedded Microcontroller

摘要:

针对普通家用汽车存在的缺少车内实时温湿度监测功能的问题，设计了一种基于单片机的便捷式车载温湿度监测系统。系统由车载监测设备、蓝牙通信模块和手机APP软件组成。车载监测设备控制温湿度检测模块实时采集车内的温湿度参数，一方面在本地液晶屏进行显示，另一方面通过蓝牙通信模块发送至手机APP软件显示。系统包括本地与远程两种方式的预警阈值设定方法，初始设定阈值的温度上限是36 ℃，温度下限是18 ℃，湿度上限80% RH，温度下限30% RH。设定完成后，车载监测设备会实时判断当前温湿度数据时候达到预警阈值，并及时进行本地声光报警。以黑龙江省哈尔滨市为例，多次测试结果表明：本系统能够在温度范围为-18 至32 ℃、湿度范围为50% 至80 % RH的环境中运行稳定，蓝牙通信模块的有效传输距离为8.2 m，不同温度区间跨度带来蓝牙通信的平均时延为265 ms。本系统具有可移植性强、装配简易、性价比高等优点，能够广泛应用于小型及中型车辆的车内环境的监测中。

Abstract:

Aiming at the problem of the lack of real-time temperature and humidity monitoring in the car in ordinary family cars, a portable temperature and humidity monitoring system for vehicles based on embedded microcontroller is designed. The system consists of vehicle monitoring equipment, Bluetooth communication module and mobile phone APP software. The vehicle monitoring equipment controls the temperature and humidity detection module to collect the temperature and humidity parameters in the car in real time, on the one hand, it is displayed on the local LCD screen, and on the other hand, it is sent to the mobile phone APP software for display through the Bluetooth communication module. The system includes both local and remote alarm threshold setting methods. The initial setting thresholds are as follows, the upper temperature limit is 36 ℃, the lower temperature limit is 18 ℃, the upper humidity limit is 80% RH, and the lower temperature limit is 30% RH. After setting is completed, the vehicle monitoring equipment will determine in real time whether the current temperature and humidity data has reached the early warning threshold, and promptly carry out local sound and light alarms. Taking Harbin City, Heilongjiang Province as an example, multiple tests show that, the system can operate stably in an environment with a temperature range of -18 to 32 °C and a humidity range of 50% to 80% RH. The effective transmission distance of the Bluetooth communication module is 8.2 m. The average delay of Bluetooth communication caused by the span of different temperature ranges is 265 ms. This system has the advantages of strong portability, easy assembly and high-cost performance, and can be widely used in the monitoring of the small and medium-sized vehicles.