LMH2832EVM-75:

Prodigy 80 points

Replies: 16

Views: 361

Part Number: LMH2832EVM-75

Hello,

I am trying to use the LMH2832evm board but the device on the board does not seem to be accessible in terms of R/W to its register.

I followed exactly the TI Guide. The USB interface is working as I can read the device ID, FTDI chip is accessible but when I use the GUI, all registers values are always "FF".

There is no Read or Write working.

The device on the board is not dead beacuse I see that it does amplify an input signal but the gain is always constant. It cannot be chenged through register.

It is as if the SPI interface between FTDI and LMH2832 chip does not work.

Thanks to let me know what can be done,

Best regards,

michel

16 Replies

  • Hello Michel,

    Is the USB status indicator being lit in the GUI? Could you please provide screenshots for both the high-level and low-level views? Is the EVM drawing approximately 204-mA (in the case of a 5V supply)?

    Best,

    Hasan Babiker

  • In reply to Hasan Babiker31:

    Hello,

    Thanks for your answer.

    - the USB indicator is OK (green)

    - USB is working as I can access FTDI chip

    - LMH2832 power consumption is either 100 (1amp) or 200 (2 amp) which seems OK.

    However all registres values remain at FF on low level view and on high level view, it does not let me change the parameters and comes back always on same values (corresponding to FF)

    Thanks

    Michel

  • In reply to michel dhoe:

    and just confirm jumpers J6 & J8 are not populated, correct?

    Best,

    Hasan Babiker

  • In reply to Hasan Babiker31:

    yes that is correct..

    Could there be any timing issue on SPI interface ?

    Thanks

    Michel

  • In reply to michel dhoe:

    Hello Michel,

    Please try installing the latest drivers for the FTDI chip found here.

    Best,

    Hasan Babiker

  • In reply to Hasan Babiker31:

    Hello,

    I installed the new FTDI driver but the situation is still the same. Power consumption is 200 mAmps, amplifier is ON but impossible to read or write the registers.

    Any idea ?

    Thank you and best regards,

    Michel

  • In reply to michel dhoe:

    I sent the screen capture in the previous email. Let me know if you didn't get it.

    Thanks

  • In reply to michel dhoe:

    Hello Michel,

    The screenshots cannot be seen, please use the Insert/Edit media button (to the left of the paper clip logo) to attach your photos to your post. Would you be able to try the EVM on another PC? It is possible that there is an SPI issue, if possible please try to all SPI signals are functioning properly (you can use the holes found in between R1 and R4).

    Best,

    Hasan Babiker

  • In reply to Hasan Babiker31:

    here we go

  • In reply to michel dhoe:

    Hello,

    It is the same on another computer.

    Moreover, when I tried a complex sequence of channels ON/OFF with jumpers, I have sometimes some access to the chip but with completely random values.

    I think there is definitely a  SPI timing issue on this EVAL board.

    I am surprised by the low quality of this EVM.

    Please advise. Can I have a board replacement ?

    I dont want to buy another expensive one to have the same problem.

    Regards,

    Michel