RTK with IMU

Sensors IMU & Motion
1

Hello!

I am considering an application which would require the combined capabilities of a device in the SparkFun RTK Surveyor series (Surveyor, Surveyor Express, Surveyor Express Plus) and an IMU. It is not an automotive application and the sensor fusion of the Express Plus to provide positioning data even when GNSS signal is lost is not of interest. Rather, I need to record accurate Euler angles (pitch, roll, yaw) alongside RTK GNSS data.

At first glance, two options and a couple of questions come to mind.

  1. Is orientation data available from the IMU incorporated in the ZED-F9R of the Surveyor Express Plus? How could this data be accessed and recorded on the Express Plus micro-SD card?

  2. Would it be possible to connect an IMU, such as the Micro 6DoF IMU - ISM330DHCX (Qwiic) to the Surveyor or Surveyor Express, and record the orientation data on the micro-SD card?

Any comments and suggestions regarding the above or any other options would be much appreciated.

Thanks in advance.

2

1 - Yes, as ESF-RAW data https://github.com/sparkfun/SparkFun_RT … 1059338377 & viewtopic.php?f=116&t=58587&p=236954&hi … mu#p236954 that can readily be processed into Euler angles/etc

2 - Yes, but not easily…the Device’s firmware isn’t pre-programmed to interface with an external IMU (and logging that to the SD card is harder still!). It’d be simpler to just get a separate board with IMU https://www.sparkfun.com/products/16832 , affix it to the unit however you’d like, and then just pair the timestamped-data sets after logging them separately.

But I’d strongly recommend saving yourself the hassles and just getting the Express Plus https://www.sparkfun.com/products/18590 (or its kit variant https://www.sparkfun.com/products/18589) :smiley:

3

Thanks for your reply and the helpful suggestions Russel. I would be quite happy to go with Option 1 and the Express Plus.

I have reviewed both of the following:

Your ESF-RAW link

https://github.com/sparkfun/SparkFun_RT … 1059338377

and

The ZED-F9R Integration manual

https://content.u-blox.com/sites/defaul … 039643.pdf

but I’m afraid my experience is more on the application software development side and my hardware integration skills are limited. I cannot see exactly how to enable recording of the ESF-RAW data on the Express Plus micro-SD card.

Could I trouble you to suggest a related tutorial or provide a brief walk-through as well as a sample file or files containing the corresponding GNSS and IMU output data.

I appreciate your help.

4

Click on the ‘documents’ tab for each product - they all have their own ‘hookup guide’ that will walk you through their operation/use, with links to the code and pictures and such