Design of Distributed Circumstance Measurement and Control System Based On CAN Bus Technology

This paper introduces that the sensor unit of temperature and humidity is connected through the 1-wire bus.SCM AT89C52 processes the measurement signal and drives the equipments,and it controls the CAN bus controller SJA1000/transceiver PCA82C250 to structure the CAN bus communication system to transmit the data.Up PC is connected with control system though the USBCAN controller PDIUSBD12,which the distributed circumstance temperature and humidity intelligent measure system is carried out.Our experiments show that the system temperature measure-error is less than ±0.4 ℃,and the system humidity measure-error is less than ±2%.The experiment results reveal that the measurement system performs well as expected.This paper introduces the system structure and the part of hardware/software design in detail.This system can be applied to circumstance measure-regulate and alarm of grain and goods' storage,spinning workshop and library,etc.