Unable to connect to Emlid Reach RX2 via Bluetooth on iOS

[balrobs]

What is the bug or the crash? What were your expectations and what actually happened?

Hi,

I recently purchased a GNSS receiver (Emlid Reach RX2) and am trying to connect it to QField on my iPhone via Bluetooth. However, I am unable to establish a connection and encounter the issue described below.

I am relatively new to working with GNSS receivers and QField, so please forgive me if this is not actually a bug but rather a configuration issue, a missing feature, or simply a misunderstanding on my part.

I would greatly appreciate any guidance or suggestions.

Thank you!

Steps to reproduce the issue

Steps to Reproduce:

1. Power on the GNSS receiver (Emlid Reach RX2).
2. Enable Bluetooth on the iPhone.
3. Pair/connect the iPhone with the Reach RX2 in the iOS Bluetooth settings.

4. Open a project in QField.
5. Navigate to Settings → Positioning.
6. In the Positioning device in use dropdown, only the following options are available:

• Internal device
• 127.0.0.1 (11111)
• 127.0.0.1 (9000)

7. Tap Add and select Bluetooth BT + BLE (NMEA) as the connection type.
8. Tap Scan for nearby devices and select RX2 from the discovered devices list.

9. Tap Connect to RX2 (BLE).

Expected Behavior
QField connects to the Reach RX2 and starts receiving GNSS position data.

Actual Behavior
Nothing happens after tapping Connect to RX2 (BLE). No connection is established and no error message is displayed.

Version

4.2.0

Operating system name

iOS

Operating system version

iOS 18.6.2

Reinstall QField

• I have a fresh install of the latest QField version, but the problem persists.
• Problem can be reliably reproduced, doesn't happen randomly.
• Problem happens with all files and projects, not only some files or projects.

Additional context

No response

[seanfsimpson]

Having the same issue…

Running iOS version 26.5.1 on an iPhone 17 Pro Max

Receiver has been working fine over BT with other apps (e.g Emlid Flow) so this bug is within QField.

See error dialog below:

[balrobs]

Thanks @seanfsimpson for confirming.
If I skip my step 3 (pairing the iPhone with the Reach RX2 in the iOS Bluetooth settings) and continue directly to step 9 (tap “Connect to RX2 (BLE)”), I encounter the same error you reported.

[seanfsimpson]

Still happening in 4.2.1

Emlid Reach RX2 is working just fine via BT with other iOS survey / mapping apps.

The developers at Emlid are aware of the issue.

[seanfsimpson]

Is this an app whitelisting Apple MFI certification issue by any chance?

[balrobs]

Still happening in 4.2.4
Is there already a guess as to what could be the problem here?

[seanfsimpson]

My guess is that the app hasn't been whitelisted with Emlid (and consequently Apple) and perhaps some integration details are missing from the app side...

[seanfsimpson]

How do these issues get triaged - or assigned or even read by someone in a position to do something about them?