How do I connect the EVAL ADXL1002 to a microcontroller?

I am trying to connect the ADXL1002 sensor eval board to a Teensy microcontroller.

The user guide does not explain what the pins are. Link to the guide is provided below. 

https://www.analog.com/media/en/technical-documentation/user-guides/EVAL-ADXL1001Z-1002Z-UG-1121.pdf

What do the following pins stand for? ST, ORo and STB?

Do I connect the following?

VDD on sensor to 3.3V on Teensy

GND on sensor to GND on Teensy

Vou on sensor to the analog input on Teensy.

Do I need to connect any of the other pins -ST/ORo and STB?

  • 0
    •  Analog Employees 
    on Jun 12, 2021 3:46 PM

    Thank you for your post!  Our primary expert, on this topic, is on vacation for another week, but I will try to help, in his absence.  

    Which Teensy platform are you using?  

    Just an idea, but you might want to consider starting with a known-good signal chain and communicate with the Teensy, using a digital interface.  If this sounds interesting, this platform 

    https://www.analog.com/en/design-center/reference-designs/circuits-from-the-lab/cn0549.html

    Please feel free to comment.  

  • Thankyou Mark. I managed to get the ADXL1002 working - the ST and STB pins had to be grounded. So this topic can be closed. 

    However, you did answer a high level problem that I had with the project. My background is in signal processing and embedded software - not in hardware design. I will have to go the route you suggest - which means purchasing a sensor with  filters at different cut off frequencies and an ADC (rather than using an analog sensor and designing the filters myself).

     I am interested in cut off frequencies of low pass filters at 1KHz, 5KHz, 10KHz and 20KHz. I will look at the information you have provided first and then have a discussion with an Analog Devices engineer before obtaining an eval sample. Would you recommend I talk to any particular contact for this or should I call your sales line and get directed appropriately?

  • 0
    •  Analog Employees 
    on Jun 15, 2021 12:04 PM in reply to Girija

    You are certainly welcome!  If I am not mistaken, the CN0549 platform provides a complete signal chain, along with documentation that illustrates which components need to change, for different filter cut-off frequencies.  Once you have a chance to review that, let's continue our discussion in this forum and if need be, we can arrange for a conference call, as well. Does that sound fair enough? 

  • 0
    •  Analog Employees 
    on Jun 15, 2021 12:09 PM in reply to Girija

    Oh, one more thing.  You may already be aware of this, but we do have a module-level product, which provides triaxial sensing, 220ksps sampling of each axis and a wide array of signal processing/storage/alarm functions, as well. 

    https://www.analog.com/en/products/adcmxl3021.html  

    Take care! 

  • That works. I am trying to see if I can get something rigged up within the next 10 days since we have an opportunity to do some test measurements in the field.

    I couldn't find documentation about changing the filter cut-off on the CN0549. Is this software configurable ? I am continuing to look through the documentation.

    Can we use a Teensy instead of the FPGA platform? I see that it can work as an Arduino HAT - but I'm assuming it is only using an SPI interface to transmit data to the Arduino and the same can be done with a Teensy. What is the advantage of using the FPGA platform instead of a simple microcontroller?

    Update: I did find the following table of the CN0540 that talks about configuring the ADC bandwidth. However the cut offs of 0.43KHz and 13.9KHz are not what I am interested in. I am trying to see if this can be set to 1KHz or 5K or 10K.

    Also, if I choose to go with the 1004 in future, is there a CN0532 equivalent with the in-built amplifier?

    I've realized that the DE-10 is only used to supply power and collect the data. But I will go with this for now since the Teensy doesn't support a 24-bit word length for data