Bad Elf Flex: Using the Bad Elf Flex with PIX4Dcatch

Bad Elf Flex: Using the Bad Elf Flex with PIX4Dcatch

Overview

This guide walks you through connecting, mounting, and configuring the Bad Elf Flex™ GNSS receiver with PIX4Dcatch on an iPhone or iPad. By combining high-accuracy GNSS with mobile 3D capture, this setup enables RTK-enabled workflows for professionals in surveying, construction, utilities, environmental monitoring, and asset management.

When properly configured, the Bad Elf Flex™ provides centimeter-level geolocation data to PIX4Dcatch, significantly improving the precision of photogrammetry and LiDAR-based point clouds. You’ll learn how to set up the hardware, apply the correct camera offset, configure RTK corrections, and follow best practices for capturing accurate, georeferenced 3D models in the field.

What You’ll Need

To successfully collect RTK-enabled 3D data with PIX4Dcatch and the Bad Elf Flex, make sure you have the following:
  1. Bad Elf Flex→
  2. Compatible iPhone or iPad (see PIX4D FAQ→ for recommended models)
  3. SP Connect case→, clamp→, or interface→ for your iPhone or iPad
  4. Bad Elf Flex Phone Mount→ to attach your iPhone or iPad to the Flex via SP Connect
  5. PIX4Dcatch app→
  6. Bad Elf Flex app→
  7. NTRIP credentials (optional, for RTK use)
  8. Valid mobile data connection or Wifi.

Pix4D + Bad Elf Scanning Kit

The full scanning kit is available as a bundle or as separate components:
  1. Bad Elf Flex→
  2. Bad Elf Flex Phone Mount→
  3. Appropriate PIX4Dcatch License→

Power On and Charge the Bad Elf Flex

  1. Fully charge your Bad Elf Flex using the supplied USB wall power adapter and charging cord.
  2. Press and hold the power button until the LED status indicators turn on.
  3. Wait for the Bad Elf Flex to acquire a GPS fix, indicated by the center LED turning green.
Notes
For the best results, place the device outdoors with a clear view of the sky, elevated away from the ground and your body.

Pair the Bad Elf Flex with Your iPhone or iPad

  1. On your iPhone or iPad, go to Settings > Bluetooth.
  2. Locate and tap Bad Elf Flex from the list.
  3. Confirm the Bluetooth pairing prompt on both the Flex and your iPhone or iPad.
Alert
If pairing fails, restart the Flex and your iPhone or iPad, then try again. For detailed instructions visit Bad Elf Flex: Bluetooth Pairing with iOS→

Update Apps and Firmware

  1. In the App Store, make sure both the PIX4Dcatch and Bad Elf Flex apps are up to date.
  2. Open the Bad Elf Flex App.
  3. If prompted, upgrade the firmware on your Bad Elf Flex.

Mount Your iPhone or iPad

Use a compatible SP Connect→ case and the Bad Elf Flex Phone Mount→ to attach your iPhone or iPad to the Bad Elf Flex.
  1. Mount in a consistent vertical orientation.
  2. Ensure the camera is unobstructed.
  3. Keep both devices stable and aligned to avoid drift or distortion.

Set Up RTK Corrections via NTRIP

With RTK corrections your Flex can provide centimeter-level accuracy to PIX4Dcatch: 

Info
Need help choosing an RTK service? See our article: Bad Elf Flex: Choosing the right RTK service→
Alert
A stable cellular or Wi-Fi connection is required for NTRIP to function.
  1. On the top-left corner of the screen, click on the GPS signal indicator and select RTK via Bluetooth.





  2. The RTK Device Settings dialog opens. Select your Bad Elf Flex.


         
                                                           
               
  3. Create a new profile.




  4. Name your profile.
  5. Select your Bad Elf Flex.
  6. Choose the appropriate orientation and phone model.

    If your iPhone model is not pre-loaded and manual measurement is required, see instructions here PIX4D: Manual Offset Measurement→




  7. Tap NTRIP Settings and Enter your NTRIP server URL, port, username, and password.
  8. Tap Validate NTRIP.
  9. Select Mount Point Select CRS (Coordinate Reference System), generally in the US, NAD1983(2011) can be selected.     

                                                                                                                                                                                                                                                                                                                                                                                           


  10. Ensure all settings look correct (3 green checkmarks) and tap SAVE.                                                              

    NotesOptional: Toggle on Auto-Connect RTK for future automatic connection.

  11. Tap Connect



  12. Ensure that you have an RTK FIX, which is indicated by the green checkmark in the top left corner of PIX4Dcatch.





Start Capturing with PIX4Dcatch

Now you're ready to capture with PIX4Dcatch.
  1. Open PIX4Dcatch and begin scanning.
  2. Move slowly and steadily.
  3. Maintain consistent device orientation.
  4. Avoid walking over the same area multiple times.
Notes
For better results, add autotags or use Ground Control Points (GCPs) during or after capture.

Troubleshooting

If you run into issues during setup or data collection, try the following steps.

Bluetooth won’t connect?

  1. Forget the Flex in your iOS Bluetooth settings and re-pair it.
  2. Restart both the Flex and your iPhone or iPad.

No RTK fix?

  1. Verify that your NTRIP credentials and internet connection are correct.
  2. Make sure the Flex firmware is up to date.
Info
Refer to our article for more information about RTK: Bad Elf Flex: Logging into an RTK network→

Position drift or inaccuracy?

  1. Re-measure and re-enter the vertical camera offset in PIX4Dcatch.
  2. Ensure the Flex has a clear sky view and is mounted in a stable, upright position.
  3. Check that your SP Connect mount is fully tightened and secure.

Need Help?

  1. Email: support@bad-elf.com
  2. Visit: Pix4D Knowledge Base →
  3. Explore: Bad Elf Flex Documentation → 




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