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BUG: GPSMap62s - altimeter


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if you press any key, the altimeter adds some meters (look at the video after 1 minute at position 1:00 )

Also if you press the screen. (Yes, it is no touchsreen.)

 

Just check it out on your gpsmap62s

 

If you see both (screen and keyboard) at the same time, it would be easier to see the problem (it's not my video)

Edited by freeday
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Not really a surprising occurrence, I suspect that most devices do the same, you just may not see the end result.

 

The pressure transducer is a highly sensitive component, any flex of the pcb that it is mounted on will change its reading. A software update could easily mask this behavior by a different smoothing algorithm/ less frequent polling of the device.

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Not really a surprising occurrence, I suspect that most devices do the same, you just may not see the end result.

 

The pressure transducer is a highly sensitive component, any flex of the pcb that it is mounted on will change its reading. A software update could easily mask this behavior by a different smoothing algorithm/ less frequent polling of the device.

I agree with this. My 76CSx altimeter will change when I put pressure on it.

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Just got an answer from Product Support Specialist/Outdoor/Fitness Team/Garmin International:

There is not an altimeter bug at this time. Rest assured if there is then the engineers will release an update to correct the issue as soon as possible.

 

So this is not a bug - it is normal behavior for the new gpsmap62s. :anibad:

 

What's going on there, GARMIN!

Edited by freeday
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:D If you place pressure on the device is would seem to me that the devices measuring circutry will measure a difference in pressure. Could it be as simple as that? B)

 

No. It shouldn't be an issue if the pressure transducer is PROPERLY ISOLATED from anything other than atmospheric pressure. My 60CSx, yet again, remains rock solid in this arena. Squeezing the case, pushing lightly on the holes in the back over the transducer, etc. Altitude doesn't change...just as it SHOULD be...

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Not really a surprising occurrence, I suspect that most devices do the same, you just may not see the end result.

 

The pressure transducer is a highly sensitive component, any flex of the pcb that it is mounted on will change its reading. A software update could easily mask this behavior by a different smoothing algorithm/ less frequent polling of the device.

I agree with this. My 76CSx altimeter will change when I put pressure on it.

Mine does too, but it seems to be a lot less than reported here:

I tried this with mine today and it does seem to be an issue. If I press down firmly on the screen or a button the elevation drops about 30' and then jumps up about 60-70' before settling back down.

If I press firmly between the top of the screen and the rocker button, the elevation will drop, but only by about 10 feet. If I release the pressure immediately, it will return to approximately the original elevation in one or two seconds. If I press and hold, it drops about 10 feet, then corrects back to the original elevation within one or two seconds. If I release the pressure after it has corrected, the elevation jumps up about 10 feet, then returns to the original elevation within one or two seconds. It may be that this is just how it works, but what g-o-cashers reported is quite a bit more variation than I see on my 76CSx.

 

I believe these units are vented, so that the pressure transducer has a connection to the outside world to get its data, and so that the buttons don’t get sucked in and stuck when you rapidly lose elevation.* But in order to maintain watertightness, the vent probably needs to be rather small. So although it will equalize pressures inside the unit and out if the pressure changes rapidly, such as by pressing on the case, it may take a while. During that time, pressure readings would be affected. It may be that the vent in the 62 is more restricted than the vent in the 76 series (and probably the 60 series), resulting in both a larger change in elevation when a given pressure is applied to the case, and a longer time to get back to normal after the pressure on the case is relieved.

 

*I read once (I think it was on gpsinformation.net a long time ago) that the buttons getting sucked in was a problem Garmin encountered in the early days when trying to make GPS units waterproof. Making them watertight also made them airtight, and the buttons were affected by changes in pressure. IIRC they solved it by using a bit of Goretex type material that would allow air to pass, but not water. I don’t know whether that is still the technology they use. They may have figured out something better by now, but it probably wouldn’t change the basic hypothesis I offered above.

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No. It shouldn't be an issue if the pressure transducer is PROPERLY ISOLATED from anything other than atmospheric pressure. My 60CSx, yet again, remains rock solid in this arena. Squeezing the case, pushing lightly on the holes in the back over the transducer, etc. Altitude doesn't change...just as it SHOULD be...

arguably true, but the point is rather that this is not a "bug" as the OP claims, as bugs are present in software and could thus be fixed by a firmware upgrade. if anything, it's a design flaw of the hardware itself.

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*I read once (I think it was on gpsinformation.net a long time ago) that the buttons getting sucked in was a problem Garmin encountered in the early days when trying to make GPS units waterproof.

 

Huh? "Sucked in"? You mean PUSHED IN from higher atmospheric pressure outside the case. Simple... Just build the things close to sea level and not on top of Mt. Everest, which would basically amount to building them with a vacuum inside the case. As for below sea level destinations, it's not exactly like people are imploding in Death Valley...or the shores of the Dead Sea in Israel, the lowest place on earth not underwater. The pressure changes are so minuscule that humans can't even detect it, much less having buttons on a GPS "sucked in". :)

 

Before anyone even tries to make the comparison, this is not the same thing as having to account for pressure changes in something like, oh say...a DIVE watch...

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No. It shouldn't be an issue if the pressure transducer is PROPERLY ISOLATED from anything other than atmospheric pressure. My 60CSx, yet again, remains rock solid in this arena. Squeezing the case, pushing lightly on the holes in the back over the transducer, etc. Altitude doesn't change...just as it SHOULD be...

arguably true, but the point is rather that this is not a "bug" as the OP claims, as bugs are present in software and could thus be fixed by a firmware upgrade. if anything, it's a design flaw of the hardware itself.

 

I know. Never said it was a bug. It, quite apparently, is closely related to a flimsy, squeaky and, presumably, crappy case design (hardware) and, quite OBVIOUSLY, cannot be fixed with a firmware update.

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*I read once (I think it was on gpsinformation.net a long time ago) that the buttons getting sucked in was a problem Garmin encountered in the early days when trying to make GPS units waterproof.

 

Huh? "Sucked in"? You mean PUSHED IN from higher atmospheric pressure outside the case. Simple... Just build the things close to sea level and not on top of Mt. Everest, which would basically amount to building them with a vacuum inside the case. As for below sea level destinations, it's not exactly like people are imploding in Death Valley...or the shores of the Dead Sea in Israel, the lowest place on earth not underwater. The pressure changes are so minuscule that humans can't even detect it, much less having buttons on a GPS "sucked in". :)

Yes, strictly speaking the buttons would be pushed in from higher atmospheric pressure outside the case, not sucked in as I said. Since this is a forum, not a scientific journal, I was writing in a conversational style. While “sucked in” is not technically correct, it is a way that many people would describe it when speaking casually. Thank you for setting the record straight on that vitally important technical point.

 

The rest of your post seems to imply that what I described wouldn’t happen because the pressure changes aren’t large enough. Maybe you haven’t experienced this, but living in Colorado, I have: I put partially full plastic bottles with flip open caps containing items like sunscreen and shampoo in my luggage, and drive from Denver at elevation 5280 to a destination at much higher elevation in the mountains. Upon arriving at my destination, I open my luggage to find that the flip open caps have popped open, releasing the contents of the bottles and making a mess. After the first incident, I learned to pack such items in plastic bags to protect my luggage and its other contents. After using the items at high elevation, I close the containers, put them in my luggage and return to Denver. When I open my luggage in Denver, I find the same bottles with their sides significantly pushed in from the change in atmospheric pressure.

 

Based on posts I’ve read from people who have disassembled their GPS units, the “buttons” are on a sheet of material that covers the actual switches. Presumably this is to help make the unit watertight. If the unit were airtight as well, it is certainly conceivable that the buttons could be pushed in, just like the sides of the plastic bottles in my luggage. I don’t know enough about human physiology to comment on why people don’t implode; but I think an airtight electronic device would be much more similar to the plastic bottles in my example than to a living organism.

 

But you don’t have to take my word for it. The original page that I referred to is here. Quoting from it (remember, this is an old article):

 

Having a unit such as the GPS 12XL this watertight is not all a bed of roses. Watertight also means airtight. When temperature and pressure changes act on a watertight (airtight) unit, pressure differentials develop. Undesired effects can occur, like the buttons being drawn down inside of the unit, or the lens over the display bowing out and potentially cracking.

 

During further process improvements, it became necessary to allow the unit to "vent", to prevent these undesired effects from occurring. To accomplish this "venting", we drilled a small (1mm) hole in the case of the unit and covered the hole with a hydrophobic membrane. This membrane allows air to pass but not water, resulting in a unit that is still waterproof, but one that can also equalize pressure differentials.

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Thank you for setting the record straight on that vitally important technical point.

 

Whatever. :)

 

The rest of your post seems to imply that what I described wouldn’t happen because the pressure changes aren’t large enough. Maybe you haven’t experienced this, but living in Colorado, I have: I put partially full plastic bottles with flip open caps containing items like sunscreen and shampoo in my luggage, and drive from Denver at elevation 5280 to a destination at much higher elevation in the mountains. Upon arriving at my destination, I open my luggage to find that the flip open caps have popped open, releasing the contents of the bottles and making a mess. After the first incident, I learned to pack such items in plastic bags to protect my luggage and its other contents. After using the items at high elevation, I close the containers, put them in my luggage and return to Denver. When I open my luggage in Denver, I find the same bottles with their sides significantly pushed in from the change in atmospheric pressure.

 

Uh, yeah, I have experienced this. One of the funniest things I've ever seen was my aircrewman covered in soda pop and chips because the plastic 2 liter bottles and bags of chips in the aft cabin, bought at the exchange (much lower elevation/altitude), blew when flying our Seahawk helicopter over the Italian Aps. The muffled "explosions" sounded like compressor stalls at first. :)

Edited by sviking
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I tried this with mine today and it does seem to be an issue. If I press down firmly on the screen or a button the elevation drops about 30' and then jumps up about 60-70' before settling back down.

 

Mine jumps about 2-5 metres if I press the screen HARD which is a far cry from 60-70'. The changes don't show on the plot but they do show on data field readout. Very interesting.

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