Design And Exploitation Of Transmitter Based On AVR Microcontroller

Transmitter is an important device in modern industrial control systems, with the analog Circuit, the disadvantage of the traditional transmitter in lacking of control and Poor anti-interference ability couldn't meet the users'requirment。With the amazing development of network and automation technology, the new smart transmitter which bases on CAN bus and MCU to replace the traditional transmitter is imperative.This subject is based on transforming traditional transmitter for automatic strapping machine. The new instrument should not only have the communication function and control function, but also possess the fundamental measurement capability. This paper selects DCD-500 of jinzhong electronic scale company as the sensor. It has exploited the AT product:ATmegal6 microprocessor, and has conducted hardware and software design. Hardware design including the microcontroller module, the sensor module, the temperature measurement modules, the power module, and the operational amplifier module, the V/I conversion module, the LCD module, the A/D conversion module and the communication module. The software design including main program design, liquid crystal display program design, the keyboard program design, temperature measurement program design and A/D conversion program design. From the Angle of system reliability, it chooses the median value average filtering algorithm as the software filter. Through third-party software Settings, it enable the transmitter communicate to the bus monitoring room.The reasons of zero drift in transmitter were analyzed in this thesis. This paper applies two currently used methods to eliminate zero drift. The two methods are Zero baseline drift compensation method and the slope of the zero drift compensation method. In order to eliminate the nonlinear error of the transmitter, the least squares curve fitting method was used in this paper. Through designing the software, it achieves point drift compensation method and the nonlinear compensation method.Considering the requirements of the transmitter control object, this paper exploits CMAC and PID control algorithm in parallel. It can get the three Parameters of PID through the test methods, and writes matlab program to simulate.Through testing the traditional transmitter and the new transmitter in practical application, it can obtain that the new transmitter has solved the anti-interference problem of the transmitter through adapting the digital signals transmission and has improved the reliability.