The Design Of Combustible Gas Alarm Apparatus Based On CAN Bus

Without any measure about the lackage of combustible gas, there will be thumping damages, even people's life. If we can judge the leakage of poisonous gas earily, and take measures before the accident enlarge, we can avoid safety misadventure. CAN bus has some outstanding merits on the aspects, such as reliability, real-time characteristic and agility. In this paper, two kinds of technologies are combined successfully in order to design the combustible gas alarm apparatus based on CAN bus.This paper generalized some means about the alarming system of gas leakage, and has confirmed the means on the system, which use fixed detedtion and field bus communication. In this paper, a kind of intelligent methane detection system is developed by technologies of compute, electron sensor, signal process etc. The system is made up of by electrocircuits of ARM microcontroller, testing, amplifier, CANbus interface, and so on. Leading functions of this system include data acquisition, the control of communication and alarm.In the side of hardware, the power supply circuit, amplifier circuit and MPU system, CANbus interface are designed. By using the AD623(operational amplifier for apparatus), restrain the noise effectively. By choosing the LPC2119 (MPU), not only reduces the complexity of circuit and the power consumption, but also realizes digital, intelligentization and network. In the side of sofeware, the design method which is based on embedded operating systemμC/OS-Ⅱis particularly introduced, The paper also introduce the task thatμC/OS-Ⅱimmigrate to LPC2119 in detail, Multi-task design not only causes programming to be more easy and the system to be more timely, but also makes the debug and the maintains more convenient.In the final, we also have carried on partial funtions of the combustible gas alarm apparatus, including sensor characteristic curve determination, enlargement factor establishment, automatic adjustment of zero and so on.