The Research Of Data Acquisition Card Based On ARM

According to the need of mechatronics measurement and control platform in college teaching, after a consideration of both cost and performance, this paper proposes a method based on MCU with ADμC 7026 treated as the main processor.The most important feature for this design is that it uses a processor with ARM7TDMI core, the main working frequency can be up to 44MHz, the ADC and DAC modules with high performance are put inside, the sampling rate can be up to 1MSPS with the sampling accuracy of 12 bits,16 channels can be obtained which are configured as analogue signals input and 4 channels can be obtained which are configured as analogure signal output for maximum, abundant peripherals are available, the full ports number of GPIO is 40.In the detail designs of this paper, the system is divided into four module: The main module is to process signals sampled by the ADC and produce analog signals; Analogue module is to make a simple condition of the signals from the sensors or waves generated by the DAC; The digital module provides 32 I/O ports, which can be used for digital sample or produce; JTAG module is used to debug or download the code in the Keil IDE environment, which will play an import part on the subsequent development of this data acquisition card. On the DAQ card, the paper tries to transplant theμC/OSⅡinto this data acquisition card, and successfully implements to manage four tasks. In the application for sampling, the system can work normal after hours.In order to test the UART communication of DAQ card, LabVIEW is used to read the data from DAQ card and displays them in wave form.To measure the specifications of ADC and DAC characteristics, an experiment is designed with DAC generates sin wave and LabVIEW displays it which are sampled by ADC, both data error of DAC and ADC are in the allowed scope of 3 LSB (Least Significant Bit), which indicates that this DAQ card has stastified the expected results of this former design.