The latest COROS firmware releases are causing issues (to some extent) on all of the watches. Official GP3S announcement is at www.gps-speedsurfing.com/default.aspx?mnu=forum&forum=1&val=219104
I have tried to illustrate the issues by driving around a short test circuit; 3 laps with total distance of 5 km. These show what is "normal" for these firmware releases but much bigger issues are evident in real session data.
logiqx.github.io/gps-details/devices/coros/windsurfing/
My advice would be to avoid any firmware release since May 2024 - 3.0408.0 / 3.0409.0 upwards, especially 3.0508.0 on the APEX Pro / VERTIX. If you have an APEX Pro or VERTIX, you can downgrade to a working firmware (3.0309.0) using the instructions at support.coros.com/hc/en-us/articles/15344945273620-How-to-manually-update-my-COROS-watch
I've not managed to downgrade my APEX 2 Pro (yet), although I believe it should be possible. If anyone has any luck downgrading their APEX 2 / APEX 2 Pro / VERTIX 2 / VERTIX 2S then please let us know how to do it.
thanks for the heads up! apex pro here. i do have a hard time figuring out relevant steps in the fw update history though. the worst glitch i saw recently was a ~ +12 kts error recorded on june 2nd, passing all GPSRv6 filters. however, the coros fw history tells me the upgrade from 0309 to 0409 wasn't released until 4 days later, june 6th that is. i can't find any fw version info in the *.fit file header, let alone info on the respective functional changes in the fw update history.
on a sidenote downgradig from 0508 to 0309 worked well following the linked instructions. still i assume i've now downgraded to the fw version that produced the worst glitches yet. imho downgrading just never is a favorable option...
cheers, basti
Select to expand quoteBasti450 said..
the worst glitch i saw recently was a ~ +12 kts error recorded on june 2nd, passing all GPSRv6 filters. however, the coros fw history tells me the upgrade from 0309 to 0409 wasn't released until 4 days later, june 6th that is. i can't find any fw version info in the *.fit file header, let alone info on the respective functional changes in the fw update history.
The + 12 kts spike will be a typical Sony glitch. My APEX Pro reported 37 knots during a wingfoiling session earlier this week.
These big spikes can often happen on COROS watches using the Sony CXD56xxxx family, and also affects other brands such as Garmin (e.g. Fenix 6). The propensity to record spikes is compounded by another trait of the Sony chipset, which is to report exactly the same speed for several seconds in a row... I've seen identical speeds for over 12 seconds. The repeated speeds allow the Sony spikes to get through the standard acceleration filter.
AFAIK 3.0409.0 on the APEX Pro and VERTIX were ok because the non-Doppler issue was introduced in 3.0508.0. The 3.0508.0 release was supposed to fix the problems affecting newer watches (e.g. APEX 2 Pro, VERTIX 2) in 3.0408.0 + 3.0409.0.
Due to the significance of the GNSS chipset in watches (Sony = bad, Airoha = good), I've collated details for all of the Garmin watches - logiqx.github.io/gps-details/devices/garmin/watches/
thanks for the detailed explanation, awesome! same here with 37.xx kts being logged for multiple iterations.
Select to expand quoteBasti450 said..
i can't find any fw version info in the *.fit file header, let alone info on the respective functional changes in the fw update history.
These are both bugbears of mine.
- It was suggested that COROS should include firmware information in their FIT files more than 2 years ago
- The FW release notes are extremely vague and lack important detail
Select to expand quoteBasti450 said..
thanks for the detailed explanation, awesome! same here with 37.xx kts being logged for multiple iterations.
One of my best Sony spikes was 50.3 knots whilst packing away my kit, just at the instant I put my arm inside the van.
