Garmin Edge 500 problems

milese

I also think this site is lacking a forum, as I dont know which is the right place for posts like this, but anyway.

I've got a Garmin Edge 500. Had it since the end of June, no problems, but recently its started auto pausing whilst I'm in motion, and seems to be doing it increasingly often. Its really annoying when I'm trying to race my local loop.

The altitude stuff is also quite far out. I dont really mind because I'm not that interested in it, but is everyone elses the same?

I've got the latest software on it.

Any thoughts? I've also pung this to Garmin to see what they say.

tigerben

snap. I have only had the unit a week or so - but I have noticed the auto-pause function kicking in whilst I am in motion ... it seems to happen when I am at near peak speeds rather than stationary. Usually resumes after a couple of seconds so an irritant rather than major problem.

I have not noticed any major issues with the altitude - I know you can configure the unit to sensitise its altitude readings.

antfly

What you can do is set your home altitude or any starting point altitude. I find the altitude to be very accurate when I do that otherwise it seems to be 2 or 3 hundred feet out.

Have you got the latest firmware?

b4beezer

Hi all,

Same problem here. I got a Edge 500 around a month ago. Three times it has shut off completely. Logged a support call with Garmin and they told me to do a factory reset on the device (press and hold 'Power' and 'lap/reset' buttons whilst the device is powered off. Done this and it happened again straight away. Very poor customer service.

One thing they also mentioned was to make sure the device was switched on 20 minutes and left in a stationary position 20 minutes before use. Haven't tried the device in the last week as I am nursing a light shoulder injury. Hope to get out again with it this weekend.

Later

JohnnyAllez

If you`ve recently updated the software via the Garmin site then I would suggest that is the problem.

I`ve not got the 500. The 705 had this same problem with auto-pause after the latest software "upgrade", Gamnin have now dropped the latest software issue and gone BACK to the last issue.

antfly

In the case of the 500 they bought out another firmware upgrade a few weeks ago which is OK. The previous one was bug-ridden so make sure you have the latest firmware, 500 owners. As for leaving it switced on for 20 mins, impratical and unnecessary if you set your altitude yourself. You only have to set it once if you always start from home.

milese

The Garmin site tells me that I've got the latest software.

Might be a stupid question, but how do I find the correct altitude for my home location?

Thanks for replies.

schweiz

antfly wrote:

In the case of the 500 they bought out another firmware upgrade a few weeks ago which is OK. The previous one was bug-ridden so make sure you have the latest firmware, 500 owners. As for leaving it switced on for 20 mins, impratical and unnecessary if you set your altitude yourself. You only have to set it once if you always start from home.

you have to set altitude on a 500?

I have 305 and a 705 and I've not come across a function to set altitude, it just picks up the nearest spot altitude from the GPS WGS84 grid [edit]http://www.esri.com/news/arcuser/0703/geoid1of3.html[/edit] and then uses barometric pressure to smooth the changes in altitude from there on in, so it's effectively auto calibrating all the time.

I had problems with auto pausing and a quick look at the garmin forums pointed to a recent firmware update on the 705 but I've not updated the firmware and still suffered from random auto pauses. I tracked my problem down to having not deleted old rides.

My theory is that when the Garmin overwrites old data I think it must do a delete before a write instead of writing directly over old data. When it's doing these deletes, I think the processor cannot cope with the data coming in and the unit auto-pauses as it has not detected a position update.

I now delete rides reasonably frequently and have had no problems since.

tigerben

You do not have to set altitude on the 500 - but you have the option to optamise it by programming in known atltitude points to give it a fix.


Thanks for the tip re deleting rides.. I will give it a go.

antfly

If you don't set the altitude it seems to be a lot slower at setting itself than the edge 305.
If you do set it the altimeter is excellent.
You can get your altitude from an OS map.

schweiz

but as the link I posted in my previous comment shows, GPS altitude is only ever an approximation to 'real' altitude as it is calculated from a mathematical geoid, therefore by entering an altitude that has been calculated from another model (i.e. the OS Grid) you're instantly adding errors to the GPS system as as soon as the Garmin re-calibrates itself, you'll most likely get an altitude jump. If the manual entry system really does help the 500 on start up, your best bet is to leave the unit somewhere with good satellite reception for 20 minutes (as more satellites improves vertical accuracy) and see what the GPS altitude is reported as. Do this several times and average the results/discard erroneous reults to counter any errors caused by pressure changes during your test.

Don't forget that with the 305/705/500/800 even the weather changing during a ride will screw up your altitude readings as a pressure front moves across bringing the good or bad weather with it.

Pokerface

If the unit is auto-pausing, maybe try turning the auto-pause feature off?

I know this isn't the fix you;re looking for, but should solve the problem. I would guess the problem may stem from the fact it is a GPS device - and if it loses contact (even briefly) with a satellite, it may think you're not moving.

antfly

It's a barometric altimeter not a GPS altimeter.It doesn't set the altitude until it has picked up your GPS position and then it says something like "elevation point detected" and sets the altitude. It works perfectly, I get no spikes and the profiles are exactly the same as the OS profiles.

schweiz

antfly wrote:

It's a barometric altimeter not a GPS altimeter. It doesn't set the altitude until it has picked up your GPS position and then it says something like "elevation point detected" and sets the altitude. It works perfectly, I get no spikes and the profiles are exactly the same as the OS profiles.

No, the base altitude is calulated from the GPS, hence why you need at least 4 satellites to have altitude (the satellite symbol at the top of the screen changes and has '3D' in it when you get 4 locked satellites). The barometric altimeter is used to smooth the altitude data.

When the unit initialises it triangulates the position of the unit from the satellites and determines the altitude from the WGS84 grid. It then calibrates this altitude against the pressure the barometer is reading. Then the unit uses pressure changes to work out you height because assuming a constant air pressure, barometric altitude will be more accurate than WGS84 which is reliant on the accuracy WGS84 model and satellite reception. However the Garmin Edges do re-calibrate. Normally this calibration is handled smoothly so doesn't show as a spike but weather fronts moving in during a cafe stop do show as spikes on data I have.

OS maps are a completely different model to WGS 84 and are typically only accurate to 10m, far less than maximum GPS accuracy in terms of resolution, but arguably more accurate given the fact they were produced by survey rather than from a mathematical formula. However, the height of the land could change any number of times between say 101m and 109m and not show on an OS map between the 100m and 110m contours.

schweiz

schweiz wrote:

Normally this calibration is handled smoothly so doesn't show as a spike but weather fronts moving in during a cafe stop do show as spikes on data I have.

Sorry, that was a poor example.

Having thought about this some more, the cafe stop spike is caused by the unit not re-calibrating in this case. The air pressure drops say 3mb, and my pressure altitude will rise by 30m, giving a step in my altitude when I re-start the ride.

However, I can see the recalibation taking place on my regular training routes when my start altitude is wrong, usually caused by not waiting for a few minutes at the start for full 3D GPS. The edge 'catches up' and you can clearly see that hills are flattened or steepened when compared to the 'normal' profiles for those routes (graph scales being equal). In these cases the finish altitude is very different from the start altitude even though there are the same place (+/-5 horizontal m) . I tend to find that the number of height gains and losses even out over a year and the margin of error is acceptable (less than 700m in 60,000m)

antfly

All I can tell you is it seems to work much better than the 305 because the start altitude is never wrong and takes about one minute to set not 20 mins.

schweiz

antfly wrote:

All I can tell you is it seems to work much better than the 305 because the start altitude is never wrong and takes about one minute to set not 20 mins.

20 mins :shock:

I think there's something wrong with your 305, or you start your rides surrounded by dense tree cover or high buildings.

My 305 takes between 1-3 minutes to initialise to a reported accuracy of <10 horizontal metres dependent on how long ago I last used it and if I'm starting from the same place I stopped last time as the unit remebers the last known position to help with faster start-up. The 705 is anything from 30-90 seconds.

antfly

No, it didn't take 20 mins most of the time, It was often wrong though, particularly if the weather had changed. Setting the altitude yourself is much better. Here is an OS profile and a 500 GPS profile for comparison.


http://nrui5w.blu.livefilestore.com/y1p ... jpg?psid=1

calvjones

Some f the gradients reported by my 500 are very flattering to the ego, but completely wrong.

On a 130km hilly sportive, I'd reckon the Garmin overestimates total m climbed by about 20% compared to say bikeroutetoaster or mapmyride.

Really gave me a shock when I thought I'd almost finished the Forest of Dean spring Classic, but had another hour and a half's horrible grind!

antfly

Bikeroutetoaster and mapmyride don't have accurate elevation.

schweiz

antfly wrote:

No, it didn't take 20 mins most of the time, It was often wrong though, particularly if the weather had changed. Setting the altitude yourself is much better. Here is an OS profile and a 500 GPS profile for comparison.


http://nrui5w.blu.livefilestore.com/y1p ... jpg?psid=1

Sorry, I've not explained myself clearly.

I'm not contesting that putting an accurate spot height into a GPS at the start of a ride will give faster acquisition, my point is that if you live in an area where the WGS84 geoid and another height model i.e. OS are significantly different then you will get height recording problems. I think it is better to stick to one height model and therefore use the WGS84 height to set your GPS, not the OS height. If you happen to live in an area where there is not much difference between the two height models then you won't see much, if any difference.

Anyway to conclude my contribution to this thread, GPS height is not particularly accurate and should be used to give you a rough guide. It's good enough for what we use it for. As I was once taught in a simulation and modelling course....all models are wrong....but they can still be very useful.

And calvjones, antfly is also correct in the fact that the Google height model used by bikeroutetoaster and others is probably the least accurate height model i've come across...I've had planned some routes that had 2000m ravines in the middle when I've looked at the profile!

milese

How do I delete old files?

schweiz

see page 34 of the owners manual

milese

Thanks. Done.

I hadn't deleted anything since I bought it in June so maybe that was contributing to the problem. I'll test it tomorrow.

I've just had a look at some of the other stuff in the manual and am looking forward to racing myself!

JohnnyAllez

So have you sorted the auto-pause problem, or is it a software issue to do with the latest Garmin update ??

rolf_f

calvjones wrote:

Some f the gradients reported by my 500 are very flattering to the ego, but completely wrong.

On a 130km hilly sportive, I'd reckon the Garmin overestimates total m climbed by about 20% compared to say bikeroutetoaster or mapmyride.

The mapping websites use digital terrain maps for elevation. The DTMs are made up of a series of tiles of a certain dimension. The resolution of the tiles determines accuracy. If, for example, the tiles were 50m resolution, and you were climbing, any descent within that 50m tile wouldn't be accounted for; you only get the difference between the tile elevation at either side. Therefore, total elevations based on a digital terrain map will always be an underestimate.

I haven't worked out what the actual tile size is - obviously, accuracy increases as tile size reduces. I have noticed Sportives reporting total climbs substantially greater than the Bikely calculation so it would be good to know how far out they are. Currently, my Bikely based total climb for the year is about 477,000 feet!

milese

JohnnyAllez wrote:

So have you sorted the auto-pause problem, or is it a software issue to do with the latest Garmin update ??

Well it didn't auto pause on the way to work this morning!

I've just realised that when I recently knocked over a minute off my PB to work it was probably only because it kept auto pausing! Its going to take some beating next time!

Finlab6

I'm sure you've done this but make sure auto pause is set to come on when stopped and not 4mph which was the default on mine