7 Replies Latest reply on Feb 7, 2017 2:38 PM by nickgray

    AD7793 discontinuous output signal

    yclo

      Hi ,

      Recently, i am working on a project of using AD7793 with Arduino mini pro as accuracy temperature measurement,

      I am using 4-wire PT1000 , 5.1k ohms (use multimeter measure 5.237k ohms) as ref resistance.

      AD7793 set ( Continuous read , Gain 4 , bipolar, external reference, current 210uA, update rate 4.17Hz . )

      The Arduino code and Matlab data acquisition code are posed as follow.

      But i get weird "discontinuous" output signal, seems it get different offset when the temperature rise or fall .

      please help me out.

      Thanks a lot

       

      YC

      Wire :

      螢幕快照+2016-07-25+下午4.03.55.png

      Arduino code :

      螢幕快照+2016-07-25+下午3.58.40.png

      Matlab code :

      螢幕快照+2016-07-25+下午3.57.53.png

      Data :

      螢幕快照+2016-07-25+下午3.50.33.png

      I scope the digital signals  as follow.

      D0  -  ~CS

      D1  -  DIN

      D2  -  DOUT/~RDY

      D3  -  SCLK

      (In continuous read mode)

      VB8012-30958A2_2016-07-27_13-10-25.png