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Oregon 600t compass changing direction


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The compass and direction of north on my Garmin Oregon 600t often changes quickly when I'm standing still or walking slowly.

 

This is especially a problem when Geocaching, as the direction to get to the cache frequently changes.

 

Is there a setting or something I can do to get more consistency?

 

I've tried calibrating the compass, but that has limited success.

 

Thanks

Edited by Eurekawegotit
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Can you share part of a track log and tell me when it is happening? It's possible that your reception is bad enough to make the device think you're moving fast enough to use a calculated vector base on GPS signals rather than the electronic compass.

 

Software version 3.10 included "Improved 3-axis compass performance" as a line item. This is probably a stupid question, but I have to ask it -- what software version are you on? (Setup -> About).

 

Try holding the device backwards (with the top of the screen pointed towards you and the bottom of the screen pointed away from you. Navigate to a point -- any old waypoint will do. Start walking at a brisk pace -- notice the compass is telling you the wrong way because you're holding the device backwards. That means it's using GPS signals to compute the direction you're moving and assumes you are holding the unit the right way (but in this case you are not). Keep holding it backwards and slowly start slowing down and the compass will eventually flip on you -- now it's using the electronic compass and the Earth's magnetic field. Try speeding up again and it will flip back to GPS compass.

 

It's possible that if you have a bad enough GPS signal reception that your position is moving around enough to flip the compass into GPS mode at some random vector. That's my guess anyways. If you post a track log (record by time at 1 second intervals) we can see how fast it thinks you were moving at the time it gets crazy.

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Try holding the device backwards (with the top of the screen pointed towards you and the bottom of the screen pointed away from you. Navigate to a point -- any old waypoint will do. Start walking at a brisk pace -- notice the compass is telling you the wrong way because you're holding the device backwards. That means it's using GPS signals to compute the direction you're moving and assumes you are holding the unit the right way (but in this case you are not). Keep holding it backwards and slowly start slowing down and the compass will eventually flip on you -- now it's using the electronic compass and the Earth's magnetic field. Try speeding up again and it will flip back to GPS compass.

 

That's good to know. Is the behaviour the same on a GPSMAP 64s?

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Anything with an electronic compas (64s, 64st) should behave similar. The reasoning is that calculating a vector from GPS signals is much more accurate when moving because it's not affected by any magnetic interference (such as walking by a metal shed).

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That explains what happened to me today: I was walking in the street with the compass displayed, and I noticed that it was turning randomly while I was walking straight.

When I was back in the office (with no GPS reception), I tested again, and the compass was very stable, I could almost make it move degree by degree by turning on my chair.

 

I guess that the satellite reception was not that good in the street because of the surrounding buildings. I will add the GPS accuracy as a data field displayed on the compass screen.

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That explains what happened to me today: I was walking in the street with the compass displayed, and I noticed that it was turning randomly while I was walking straight.

When I was back in the office (with no GPS reception), I tested again, and the compass was very stable, I could almost make it move degree by degree by turning on my chair.

 

I guess that the satellite reception was not that good in the street because of the surrounding buildings. I will add the GPS accuracy as a data field displayed on the compass screen.

Just curious: Did you have GLONASS enabled or disabled?

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That explains what happened to me today: I was walking in the street with the compass displayed, and I noticed that it was turning randomly while I was walking straight.

When I was back in the office (with no GPS reception), I tested again, and the compass was very stable, I could almost make it move degree by degree by turning on my chair.

 

I guess that the satellite reception was not that good in the street because of the surrounding buildings. I will add the GPS accuracy as a data field displayed on the compass screen.

Just curious: Did you have GLONASS enabled or disabled?

 

Yes, GLONASS was enabled, as well as WAAS/EGNOS.

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I was able yesterday to confirm what insig wrote, as I was in a train on a seat facing backwards. The train was travelling from north to south.

The 64s had its antenna oriented to the north, I was displaying the compass and data fields, compass heading that was indicating 0°, and GPS heading that was indicating 180°.

Concerning the compass itself, when the train was running, it was indicating 180°, i.e. the GPS heading. But as soon as the train stopped in a station, it was indicating 0°, using this time the compass heading.

 

That's the kind of thing that I would really need to find in the documentation!

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I was able yesterday to confirm what insig wrote, as I was in a train on a seat facing backwards. The train was travelling from north to south.

The 64s had its antenna oriented to the north, I was displaying the compass and data fields, compass heading that was indicating 0°, and GPS heading that was indicating 180°.

Concerning the compass itself, when the train was running, it was indicating 180°, i.e. the GPS heading. But as soon as the train stopped in a station, it was indicating 0°, using this time the compass heading.

 

That's the kind of thing that I would really need to find in the documentation!

 

In addition, you'll find that in many cars, the electronic compass doesn't work at all as the car body messes with the magnetic signal.

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Can you share part of a track log and tell me when it is happening? It's possible that your reception is bad enough to make the device think you're moving fast enough to use a calculated vector base on GPS signals rather than the electronic compass.

 

Software version 3.10 included "Improved 3-axis compass performance" as a line item. This is probably a stupid question, but I have to ask it -- what software version are you on? (Setup -> About).

 

Try holding the device backwards (with the top of the screen pointed towards you and the bottom of the screen pointed away from you. Navigate to a point -- any old waypoint will do. Start walking at a brisk pace -- notice the compass is telling you the wrong way because you're holding the device backwards. That means it's using GPS signals to compute the direction you're moving and assumes you are holding the unit the right way (but in this case you are not). Keep holding it backwards and slowly start slowing down and the compass will eventually flip on you -- now it's using the electronic compass and the Earth's magnetic field. Try speeding up again and it will flip back to GPS compass.

 

It's possible that if you have a bad enough GPS signal reception that your position is moving around enough to flip the compass into GPS mode at some random vector. That's my guess anyways. If you post a track log (record by time at 1 second intervals) we can see how fast it thinks you were moving at the time it gets crazy.

Link to comment

Can you share part of a track log and tell me when it is happening? It's possible that your reception is bad enough to make the device think you're moving fast enough to use a calculated vector base on GPS signals rather than the electronic compass.

 

Software version 3.10 included "Improved 3-axis compass performance" as a line item. This is probably a stupid question, but I have to ask it -- what software version are you on? (Setup -> About).

 

Try holding the device backwards (with the top of the screen pointed towards you and the bottom of the screen pointed away from you. Navigate to a point -- any old waypoint will do. Start walking at a brisk pace -- notice the compass is telling you the wrong way because you're holding the device backwards. That means it's using GPS signals to compute the direction you're moving and assumes you are holding the unit the right way (but in this case you are not). Keep holding it backwards and slowly start slowing down and the compass will eventually flip on you -- now it's using the electronic compass and the Earth's magnetic field. Try speeding up again and it will flip back to GPS compass.

 

It's possible that if you have a bad enough GPS signal reception that your position is moving around enough to flip the compass into GPS mode at some random vector. That's my guess anyways. If you post a track log (record by time at 1 second intervals) we can see how fast it thinks you were moving at the time it gets crazy.

 

Many, many thanks for your reply. I checked the software and I had version 2.60! I've now upgraded to the current version (4.60) and it seems much better.

 

I'll also try your other suggestion tomorrow, but for now, appears to be fixed. Thanks again.

Edited by Eurekawegotit
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