SW Maps issues on iOS

GPS/GNSS
1

Hello everyone,

I’m seeking community advice regarding some persistent issues with my Sparkfun RTK Surveyor setup on iOS. Despite multiple attempts to contact the app developer, I haven’t received a response, so I’m hoping to see if others have found workarounds for the following:

1. Bluetooth Disconnection: During track logging, the Bluetooth link to the GNSS receiver frequently drops after approximately 20 minutes when the screen is locked. I have already disabled “Low Power Mode” & "Adaptive Power, with “Background Refresh” enabled, but the issue persists. This seems related to iOS background execution policies or power management killing the connection.

2. Cellular Stability Affecting Bluetooth: I’ve noticed a correlation where the Bluetooth connection often drops whenever cellular reception becomes unstable. This leads to significant gaps in our track logs and loss of data integrity during field operations.

3. NTRIP Auto-Reconnect Failure: When cellular reception is restored after a dropout, the RTK connection to the NTRIP server fails to reconnect automatically. We are forced to have staff manually monitor the signal and reconnect every few minutes to maintain a Fixed solution. A background auto-reconnect feature (e.g., every 5 seconds) is desperately needed to ensure accuracy.

It is quite frustrating for our field team to manually manage these reconnections constantly. Has anyone experienced similar stability issues on iOS?

Any comments or suggestions would be greatly appreciated.

2

Welcome to the forum @Infinity :smiling_face_with_sunglasses:

Yes, I’ve experienced that also.

I just now cranked up a Surveyor, connected to it and NTRIP in SW Maps, started a Track, and locked the screen on iPhone to see if I have the same issues as you. But I expect iOS will kill it without the screen being active/On, as you’ve described. I’ll let ya know.

[Edit]: SW Maps stayed connected and working for a couple of hours while the iPhone screen was locked.

Have you ever considered the PostCard & Portability Shield ? Those allow for automatic NMEA logging to the microSD card, without needing any external device or software. The Postcard can be configured to connect to the phone’s wifi hotspot, and the RTK Everywhere firmware has a NTRIP client built-in for a head-less setup. Just a thought… :nerd_face:

3

  1. Can you disable the low-power modes on iOS that kick in at ~20 mins? On Android and it’ll let me lock permissions for that kind of thing

  2. I imagine this is due to the correction data not being available for transport because low cell signal → dropped frames → bluetooth disconnecting…if a different carrier has better signal or if you can hotspot a 3rd device nearby that might help

  3. I believe some of the other RTK devices have this…

Are you using the devices in areas that lend themselves to PPP? It might be worth exploring as an alternative

4

Hey rftop, thanks for your reply.

Yup, I got pretty much same result in good reception areas, but at bad reception areas, the Bluetooth starts to disconnect frequently.

I don’t have plan to get a PostCard for post processing coz I would prefer getting real time result on screen :slight_smile:

5

The PostCard would still give you the same real-time results on the smartphone as the Surveyor. Plus the PostCard’s RTK Everywhere has more features than the Surveyor. I only mentioned it because of the ability to save the NMEA to the microSD card as a backup. That could eliminate your “significant gaps in our track logs and loss of data integrity during field operations” which is caused by SW Maps.

I’ll test this with my Surveyor. I cant imagine why SW Maps would disconnect from the BLE receiver just because the NTRIP (cellular) was lost, but I do believe ya :wink:

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