Discussion: A Garmin Christmas Present

My Garmin 620 went for a trip last night, through the wash cycle. My wife found it and the battery was dead, I plugged it in to recharge and it seemed to work. Looked on my "activities" and found that it must have turned on as the wash started and went 2.47 miles (and gained 13 ft) in a period of 2 hours. Have taken it on a short trip this morning and it seems to work. A nice Christmas present. Oh, and I guess it really is waterproof......

Definitely waterproof but I question the elevation gain of 13 feet during the wash cycle.

The elevation gain should either have been higher (assuming a side loader machine) or close to zero (i.e. a top loader). The elevation algorithm will normally try to eliminate local oscillations on the order of normal wrist movement while running, right?

Since the washer is almost certainly metal exterior and hence a pretty good Faraday cage, I would be astonished if any contribution to either distance or elevation gain came from the time when it was actually inside the washing machine, since it wouldn't really have a chance of seeing any satellites. Could the on-off button action somehow have happened before or after the actual washing? Did it show an actual start time of the activity as well as the time elapsed? I guess I have seen some side-loading machines with a glass window on the door, but still a little surprising even then to have gotten good enough signal to locate satellites.

Wins thread of the year.

The start of the track was when it was put in the washer and the washer was started. There was no wrist movement as I was sitting in a chair in the living room and the device was in the washer. I, too, was amazed that the signals from the GPS satellites was recorded because it was in a metal cage. That is supposed to prevent radio signals from getting to the device. It may be that there were brief glimpses of contact and they were a bit random. Basically, I have NFC as to why it survived or gave what was basically a track with random motion. Yeah, quite a bit because it was quite a long trace.....

If you look at the gpx record (or show the track superimposed on Google maps), does the location of the recorded points bear any resemblance to the location of your house? And is all of the motion restricted to the first point or two? Often the first point of a track is way off, if the device hasn't actually managed to locate more than 3 satellites yet, and makes a random guess on elevation to get started. I'm still wondering about whether it got started just slightly before getting loaded into the machine, while being carted around in laundry basket or in the process of being loaded into machine, and able to get a bit of a signal momentarily just before lid closed on washer.

Time to repeat the experiment, making note of the actual start time and location. :-)

I'm more concerned with the fact you have a two hour wash cycle...

As to the distance, well I tend to move hundreds of metres (apparently) when sitting stationary on the windtrainer under our back veranda so it's not all that surprising (although picking up satellites inside a washing machine is).

Re the Faraday cage effect, I think that depends upon the build quality of the washing machine. We have a front loading Asco and its metal and glass. My impression of modern top loaders is that they have a lot of moulded plastic.

The 620 has an accelerometer that it will use to count “steps” for distance/speed estimation when GPS is not available.

With regard to the 2 hour wash cycle, it may have been that after it got started, it ran until the battery ran down. When it was taken from the wash, the battery had 0%. This is a side loader so the metal probably blocked most GPS signal. With regard to it counting steps, I wonder why it chose the directions that it chose to go in.....