I2C response on write (but none on read) command?

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  • japlytic
    Badcaps Legend
    • Oct 2005
    • 2086
    • Australia
    #1

    I2C response on write (but none on read) command?

    You may have heard that some hardware registers are write only (any read would be meaningless), but I may have seen certain I2C bus devices which are write only and do not give an acknowledge on a Read command, such as certain DACs.

    I think it is a bad idea to give an acknowledge only on an I2C Write command (but no acknowledge on Read), especially when using an I2C bus scan routine (read only; checking for acknowledgement for writing with an I2C bus scan with the wrong data can have unintended consequences).
    My first choice in quality Japanese electrolytics is Nippon Chemi-Con, which has been in business since 1931... the quality of electronics is dependent on the quality of the electrolytics.
    Tags: None
    • brethin
      Badcaps Legend
      • Dec 2008
      • 1907
      • USA
      #2
      Re: I2C response on write (but none on read) command?

      Writing requires acknowledgement reading does not. It is the standard and you just have to live with it unless you plan to design your own device and write your own command set.

        Comment

        • stj
          Great Sage 齊天大聖
          • Dec 2009
          • 30952
          • Albion
          #3
          Re: I2C response on write (but none on read) command?

          if you send a read command and you get data back - is that not an "ack" in itself?

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