info.heading and compass calibration

Hi,

I have a question, maybe ConnectIQ guys can provide answers, or some other developer having used info.heading can provide some more information or experience.

my app uses the compass to detect swimming laps.

it is not very common, but from time to time some users report that the app is not working for them. my app writes the heading data in the fit file, and i have realized in some of these activities, the heading reacts slow, like "lazy".

this has never happened to me. but yesterday i was testing a beta version of the app, and finally i had a similar behaviour. i have a screen where a show heading for diagnosis purposes. and I saw that heading was behaving erratically. i could reproduce the error for a while. and finally i shook my hand, and heading begun to work fine again. i have not been able to reproduce the error again.

this has made me think, that maybe this is a heading calibration issue of the watch. the app is meant for fr230, 235 and 630.

there is no menu to calibrate the compass, while it is common for watches having a compass to incorporate a menu to calibrate it. typically you will enter some menu, and move your hand in the air drawing an "8". I have attached below some videos which show what i mean.

that the fr23x have a compass is not really documented in anyplace, as far as I know. it is like a bonus feature discovered thanks connectIQ.

have you had any similar issues with your apps and these devices? can GARMIN comment something on this?

fenix 2
https://youtu.be/JLjIWQ0p5Ps?t=15

fenix 3
https://youtu.be/yJZaZGGPtiM?t=80

ambit2
https://youtu.be/ICmPvpkLQAw?t=43

thank you in advance

jim_m_58 over 8 years ago

I have a 230, and noticed quite a while back that it seemed to have a compass, but found it to be often quite off. And with no way to calibrate it, I'm not sure what can be done. The va-hr also has a HW compass, but with it you can calibrate it and it seems to work fine.

After a hard reset and before calibration, va-hr could also be off though (same with the altimeter).

danielp27 over 8 years ago

thanks jim,

that the compass is off does not matter for my app. i just compare the angle in both directions, and the difference has to be around 180°. that works very good. most of the people are having a good experience.

it is the "laziness" what has caught my attention. maybe a one time thing...

Former Member over 8 years ago

I think that the source of this problem lies in the fact that heading is provided based on GPS coordinates if satellite coverage is available and using hardware compass (if any) in any other case. Considering that you constantly loose GPS signal during swimming while your hand with the watch goes under water, I'd try to disable GPS completely for the activity so that compass will take priority.

danielp27 over 8 years ago

hi,
thanks for the reply.
i forgot to mention: gps is always off. it detects turns when swimming indoor.

yes, compass takes priority. this works fine.

the issue is that under some unknown circunstances, compass became erratic. in my case, shaking the arm fixed the issue. it has happened to me just once in 4 months. not sure if that is what users are experiencing from time to time.