External clock with ADIS16488 + EVAL ADIS2

Hi,

I was given a ADIS16488 sensor with its relevant evaluation board  EVAL-ADIS2.

I would like to know if it is possible to drive the ADIS16488 sensor with an external reference clock while it is connected to the evaluation board.

More, can you consider in your future software version to include the possibility to log the timestamps associated to IMU's raw data ?

Thanks

  • 0
    •  Analog Employees 
    on Mar 15, 2018 9:54 PM

    Thank you for your post.  The ADIS1648x IMUs support an external clock through their DIOx pins, which are configurable through the FNCTIO_CTRL register.  The EVAL-ADIS2 provides access to the DIOx pins on the ADIS16488 IMU, through dedicated e-holes, as shown in the following picture. 

    Were you also given an ADIS16IMU1/PCBZ, to connect the ADIS16488 to the EVAL-ADIS2 with? 

    What would the time stamp need to represent?  Are you able to quantify how accurate the time stamp would need to be, in order to meet your intended us?  In past consideration, we were not sure that we could correlate the common PC-based time functions with the data sampling times of each sensor, with sufficient accuracy, so we purposely left them out.  Look forward to any specific metrics or insights that you can provide on this topic. 

  • Thank you very much for your prompt replay.

    Yes, I've got also ADIS16IMU1/PCBZ for IMU connection. I believe the capability to synchronize IMU's raw data with an external reference it's critical for IMUs, since GNSS+IMU applications are more and more requested. GNSS data are updated @ 1Hz, and for ground vehicle applications IMU's refresh rate of 200 Hz is a good tradeoff.

    Accuracy it's not that important as one could believe, at least in such applications, since GNSS+IMU raw data are processed through a Kalman Filter that easily deals with little time shift. I guess 0.5 ms accuracy it's a good value. Another important feature is the capability to log the timestamp, that unfortunately I didn't find in your IMU evaluation tool. I need to post-process IMU's raw data and it's hard to do it without any time reference.

    Since I'm assessing several COTS IMUs, let me say that I was surprised to find such a nice product (ADIS16488 BMLZ + EVAL-ADIS2 + ADIS16IMU1/PCBZ) with a poor documentation for the evaluation board. Fortunately you have a very efficient online support, but I suggest you to collect all the useful info you are providing here and embed them in EVAL-ADIS2 wiki page, where I didn't find any mention about DIOx pins  and how to deal with them.