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arifkhan
Associate II
April 8, 2026
Question

asm330lhhxg1 "who_am_i" register is reading back 0x48. Should be 0x6.

  • April 8, 2026
  • 15 replies
  • 456 views

Connected STEVAL_$MKI243AA board to a nucleo-g491re board using 4 wire spi interface. The spi bus is setup to run @ 146 Kbits/sec. Reading back bad data. 

WHO_AM_I is 0x48

PIN_CTRL is 0x3E

 

Not sure but seem like the device is power

15 replies

TDK
TDK
April 8, 2026

Why should it be 0x6?

Screenshot 2026-04-08 102959.png

 

"If you feel a post has answered your question, please click ""Accept as Solution""."
    Federica Bossi
    Federica Bossi
    ST Technical Moderator
    April 16, 2026

    Hi @arifkhan ,

    The correct whoami, as reported also by @TDK , is 6Bh.

    Probe with a logic analyzer and check:

    • MOSI address byte
    • MISO timing
    • whether the returned byte is shifted by 1 bit
    • whether CS stays stable

    Did you try the reading also in I2C or SPI3?

    In order to give better visibility on the answered topics, please click on 'Best answer' on the reply which solved your issue or answered your question.
      arifkhanAuthor
      Associate II
      April 16, 2026

      hello Federica,

       

      Yes, i have the scope connected to the 4 spi signals, I see 0x8F go out on the MOSI and I see 0x48 on the MISO wire every time.  I put a 10k pullup on the CS wire and also a 10K pulldown on the INT1 signal.

       

      Yes I tried the I2C bus and I am able to read 0x6B data back from the WHOAMI register.

       

      Rgds

      arifkhanAuthor
      Associate II
      April 23, 2026

      hello Federica,

       

      Is there some setup to this part at power up ?

       

      I am completely at loss right now I would really appreciate some help from ST micro.

       

      Rgds

       

      arifkhanAuthor
      Associate II
      April 24, 2026

      I am really disappointed with the help i have received from ST micro. 

      I should start looking for an alternate solution and and also transition away from using all STmicro parts in the future given there level of support.

      Andrew Neil
      Andrew Neil
      Super User
      April 27, 2026
      @arifkhan wrote:

      I am really disappointed with the help i have received from ST micro. 

      You still haven't provided your schematic, or any code

      How to write your question to maximize your chances to find a solution

       

      Something is clearly very wrong with your MISO:

      @arifkhan wrote:
      AndrewNeil_0-1777278462869.png

      Do you have a good ground connection?

      A complex system that works is invariably found to have evolved from a simple system that worked.A complex system designed from scratch never works and cannot be patched up to make it work.
      Andrew Neil
      Andrew Neil
      Super User
      May 5, 2026

      I composed this reply some time last week, but it doesn't seem to have got published.

      Fortunately, the forum kept a draft:

      A good, clear photo of your actual setup would help.

      Check connections very carefully - particularly Vdd & GND.

       

      @arifkhan wrote:

      The two evals boards are jumpered as shown with 8" jumper wires.

      These are quite prone to poor connections.

      As noted above, your MISO behaviour very much suggests poor connections.

       

      I would strongly recommend one of the X-Nucleo-IKS adaptor boards ("shields") - which accommodate the 24-pin DIL pinout; eg,

      X-NUCLEO-IKS5A1 - X-NUCLEO-IKS02A1 - X-NUCLEO-IKS4A1

      AndrewNeil_1-1777454891377.png

       

      These models are Obsolete, but still usable if you happen to have one:

      X-NUCLEO-IKS01A3 - X-NUCLEO-IKS01A1

      A complex system that works is invariably found to have evolved from a simple system that worked.A complex system designed from scratch never works and cannot be patched up to make it work.
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