Research And Design Of The Combustible Gas Detector And Alarm Based On ARM7

With the rapid development of economic and technology, the level of people's life has been improved. Coal, oil and natural gas have been used widely in our lives working as the vital energy and chemical raw materials, and any field can't work well without them. They can take many convenient for our lives. Meanwhile, they can also take danger to our life. Under the background, the thesis put forward a kind of Combustible gas Detector and Alarm, which can test the Concentration of Combustible gas in air. Therefore, people can take some measures to avoid accident. Only in this way, people's personal and property safety can be insured.This thesis has used embedded technology, the technology of Signal processing, digital circuit technology, analogy circuit technology and some related electronic technology. The main function of the Combustible gas Detector and Alarm which is based on ARM7is to test the concentration of combustible gas and the concentration of oxygen in air in time and to display the concentration of combustible gas and the concentration of oxygen. While the concentration of combustible gas is over Alarm threshold, the Combustible gas Detector and Alarm will send alarm signal. Two design aspects are mainly included in this thesis:the hardware design respect and the software design respect.In hardware design respect,the thesis is composed by the circuit of detecting, signal Amplifying, AD conversion, alarming,the circuit of displaying, keyboard, checking meter,the circuit of zero adjustment,the modular of GSM and the circuit of power supply and so forth. Taking cost and power consumption into account,the thesis that based on the real-time requirements of detecting the concentration of combustible gas,and put forward the design scheme which use ARM7as the main controller, and then introduce respectively the choice of CPU, the circuit of signal Amplifying, AD conversion, the circuit of alarming,the circuit of displaying and the circuit of keyboard, the circuit of checking meter,the circuit of zero adjustment,lastly the thesis introduce some measures about Anti-interference.In software design respect, the thesis introduce the Kernel and Function of Embedded real-time operating system uC/OS-â…¡,and then the thesis introduce the process of transplanting uC/OS-II to LPC2138.At last, the thesis introduce and analysis the process of designing driver program and flow process chart.