Research And Design Of Indoor Environmental Parameters Monitor

Along with economic development and the increase of the quality of living standard, the living environment has caused more and more attention. Various diseases such as respiratory disease and cardiovascular disease due to adverse environment make more concern. The indoor environmental parameters monitor thus goes into the ordinary family gradually.By monitoring the indoor environmental parameters such as temperature, humidity, light intensity, the concentration of formaldehyde, carbon monoxide and giving an alarm when any environmental parameter is abnormal, it ensures that the people always have a full understanding about the quality of the living environment and protects people’s health. Therefore it is very meaningful to study and design a kind of indoor environmental parameters monitor which is versatile, simple to operate and has high reliability.The subject uses the sensor technology, embedded technology and communication technology to complete the monitoring of indoor environmental information.The system uses LPC2138ARM microprocessor of NXP corporation as the core processor of the monitor. By porting uCOS-Ⅱ multi-tasking operating system onto LPC2138and cutting its features,it achieves the scheduling and switching between multiple users’tasks. By using a variety of sensors and integrated chips it completes detection of the environmental parameters. By using a LCD monitor called LCD12864it can interact with any user. By using a16-key keyboard encoder chip called MM74C922it can scan four by four matrix keyboard automatically to access the user’s keyboard input information in real time. By using a body infrared sensor and its detection circuit it can monitor human activities around. By using a buzzer and an amplifier circuit it can give a sound alarm when any environmental parameter is abnormal. By using a global mobile communication chip called GTM900C which is developed by Huawei corporation it can send a short message for alarm when any environmental parameter is abnormal. The paper studys the application method kernel function in the uCOS-11operating system and designs uCOS-Ⅱ tasks and application program for the frontal functions and designs system program. To achieve the short message alarm function, the papar designs AT command procedures of GTM900C.When the monitor works properly after power-on,users can configure environmental parameters to be monitored according to different needs and set upper or lower alarm limits of environmental parameters according to the actual need. Users can also take advantage of the real-time clock system of the monitor to set up and re-adjust the current time. The indoor environmental parameters monitor in the paper is versatile and can be operated simply.It is not only reliable but also versatile. It can communicate with a handheld mobile device. It takes some certain measures to reduce system power dissipation.It provides a new reference for monitoring methods of indoor environmental parameters.