Tms320f2812-based Data Acquisition And Transmission Of The Can Bus,

Data collection systems are widely used in the fields of research,education,industry,and irrigation.With the rapid development of computer and information technology,digital signal processing technology has been more and more important in high-speed and real-time processing.The appearance of DSP chip makes the arithmetic of digital signal processing come true.Based on TMS320F2812,our system completes the acquisition to one anolog signal. The acquisited data is storaged in the chip's memory temporarily,then it is filtered and transmitted to PC.As this chip has abundant of peripheral,we can have a simple circuit architecture,a low cost and a short development time by using it.The paper introduces design scheme,including device interface and software design on each part.In the data acquisition part,we use the 12-bit ADC of the chip.The paper introduces specific soft design.Generally,the input signals are dual polarity in the actual situation.So the dual polarity signals are convered to single polarity signals before ADC.The convert cicuit is showed in the paper.Due to the internal errors of the F2812 influence the system percision,we give the ways to improve sampling precision.In the digital filter part,we design FIR low filter by using window fuction.In the system, we use FDATool in the Matlab,We design the appropriate filter by using FDATool and generate filter coefficients in the header file,added to the filter project.This way has a good point.Assuring the name of the header file fixs,the filter coefficients in the header file is changing with the change of the filter parameter.It is convenient for debugging and shotcuts the DSP development cycle.Data transmission is based on CAN bus.F2812 eCAN module integrates CAN controller which supplys the whole CAN protocol and reduces the CPU overhead.It only needs the outer transceiver.In our system,the transceiver is SN65HVD230 of TI company,which is the interface between CAN controller and physical bus.In the paper,we give the software design of CAN initial and message transmission.