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.

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

    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.  

    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