GPS Polling Rate

Hello,

I am the developer of HotLap, and am very interested in the ability to change the GPS rate from the default 1Hz to 5Hz or greater. It sounds like this is already a firmware capability for the default Downhill biking/skiing/snowboarding activity (which bumps it to 5Hz) for the Fenix 8 and other models, but there is no way to use/set the rate from the API that I have found. Does anyone have any information or know of ways take advantage of the higher sampling rate as my app can dramatically benefit from these higher sampling rates for Motorsport use (at high speeds in cars/on track, etc).

Thanks in advance.

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jim_m_58 14 days ago in reply to dustinsterk +1

The fenix9 devices have new Position configurations. See Fenix 9 Position.CONFIGURATION_GPS_xxxxx not supported

Including "max accuracy"

but I've seen nothing that indicates 5hz recording.…
Mike K888 7 days ago +1

5 Hz recording is one of the most desirable features of the speedsailing (aka speedsurfing) community, many of whom own a Garmin and wear it on the water (typically using the APPro Windsurf app). Without…

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dustinsterk 14 days ago in reply to jim_m_58

That is the reason for my post...I am looking for any information if this is indeed true, and if so, can we expect any updates to the SDK - and pushing for this to be a feature request if not currently planned.

jim_m_58 14 days ago in reply to dustinsterk

The fenix9 devices have new Position configurations. See Fenix 9 Position.CONFIGURATION_GPS_xxxxx not supported

Including "max accuracy"

but I've seen nothing that indicates 5hz recording. My hike2 app in the store supports the 4 new configuration on the f9 devices,

Maybe someone with a f9 can try it as well as native skiing and by looking at the size of the fit file on the garmin. see if this isn't a 5krunner misunderstanding.

dustinsterk 14 days ago in reply to jim_m_58

I actually do have a f9 myself, but have not had a chance to try this firsthand with any sort of downhill activity.

dustinsterk 10 days ago

Anyone from Garmin support willing to comment on this?

jim_m_58 10 days ago in reply to dustinsterk

What you can try at home with your f9: It might help provide some info

Start a downhill ski activity and spend 10 minutes just walking around the house.

Do the same with the native walk activity

Use the same recording mode for both (probably every second)

Take a look at the two fit files on your f9. If downhill was recording at 5hz, it's fit file should be noticeably larger. You can also use a fit file viewer to check.

dustinsterk 10 days ago in reply to jim_m_58

Did that and analyzed the files. All the profiles seem to have the gps_metadata (message number 160) which would allow writing at up to 5Hz. I also confirmed the gps on the fenix 8 is the Synaptics SYN4778 GNSS chipset (no idea what the fenix9 has just yet) which can record up to 10Hz. The question is, if I start to move faster than say XYZmph will the firmware start recording data at a higher rate. I will have to test that once it is daylight.

jim_m_58 10 days ago in reply to dustinsterk

Yes, try downhill ski again and record 10 minutes while driving. The fit file will be larger of the recording is at 5hz. Is the5kRunner your only source for the 5hz stuff

dustinsterk 9 days ago in reply to jim_m_58

Completed a "MTB" activity in my car with the Fenix9: Through all of that, record stayed at exactly 1 Hz and gps_metadata stayed at exactly one message per second with a two-field altitude/speed layout. Nothing went above 1Hz. . You can see Garmin has allowed the .FIT format to work with the confirmed unlocking of 5Hz on the Garmin Edge devices: https://www.dcrainmaker.com/2025/06/garmins-new-edge-mtb-cycling-gps-review-hows-it-different.html. So it is possible, it just needs to be enabled in the watch firmware/SDK.

jim_m_58 9 days ago in reply to dustinsterk

The 5hz looks to be only with MTB while descending (by default). (it won't be writing 5hz data all the time, so the fit will be smaller).

I can also see that as a reason they don't allow it from CIQ (there already are the new GPS configurations for the f9). The reason being size of the fit. Think of all the fit files GC deals with, and allowing CIQ apps to do 5hz, could mean many much larger fit files GC has to deal with

dustinsterk 9 days ago in reply to jim_m_58

The size of the .fit file should be a rounding error in their overall AWS (or other cloud provider) budget. I am sure they are all persisted in low cost object storage. I would like to hear from someone on the Garmin product/dev team on the real limiting factor.