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Bit- banging the AD2174-8 on a EVAL-AD7124-8SDZ board

Question asked by sgorman on May 21, 2017
Latest reply on May 22, 2017 by JellenieR
  •  Thank you for your previous reply to my bit-banging question.

    I'm bit-banging an AD7124-8 on a  EVAL-AD7124-8SDZ board.

    Thanks to your  help I have been able to read channels 0 and 1 differential. I then saw that channels

    8 and 9 were available so I switched my inputs to 8 and 9, but have not seen any response on reading

    the data register.


    This works


    Ch.0 pos   Ch.1 neg


    digitalWrite(SELPIN,LOW;   // CS low

    void loop(){
    int commandbits =  0x09;

    int commandbits1 = 0x80;

    int commandbits2 = 0x01;

    int commandbits3 = 0x19;

    int commandbits4 = 0x08;

    int commandbits5 = 0x18;

    int commandbits6 = 0x42;

    int commandbits7 = 0;

    int commandbits8 = 0;

    int commandbits9 = 0;

    digitalWrite(SELPIN,HIGH);  // CS high
    }

     


    This doesn't. Jumps around just above 0V no matter what voltage

    I put across CH.8 and CH.9.


    Ch. 8  pos   Ch. 9 neg


  • digitalWrite(SELPIN,LOW;   // CS low
    void loop(){

    int commandbits =   0x11; //  Channel  8

    int commandbits1 = 0x81; //  0x80 is enable   setup 0  last bit for pos ch. 0x01

    int commandbits2 =  0x09;  //   neg ch 9

    int commandbits3 = 0x19; // Configure setup 0

    int commandbits4 = 0x08; // bipolar

    int commandbits5 = 0x18; // Vref = AVcc

    int commandbits6 = 0x42;  // Read data

    int commandbits7 = 0;

    int commandbits8 = 0;

    int commandbits9 = 0;
    digitalWrite(SELPIN,HIGH);  // CS high

     

What am I missing?

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