Forums > Windsurfing   Gps and Speed talk

About GT31 EOL

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Created by b14 > 9 months ago, 12 Aug 2013
b14
60 posts
12 Aug 2013 4:40PM
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I got mail from Locosys Stasy. Just now.
Someone know it already?
So what is next GPS or I have to order ?

b14 Yoshio
-------------------------------------------------------------------------------------------
Dear sir,

Good day!

This is an official phase out notice for LOCOSYS.
Some key components inside of GT-31/BGT-31 were notified by suppliers for EOL.
You can refer to attached document.

If you do have any demand, please contact us before 2013/9/30.
Otherwise, we will not have enough reaction time.

Thanks in advance.

sailquik
VIC, 4626 posts
12 Aug 2013 10:16PM
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I became aware of this message last night from our USA WGPSSRC committee member. We immediately began to try to seek clarification of what it really means.
It is very disturbing news if there is no like replacement planned. Our whole GPS windsurfing movement is built around the accuracy and customized features of this device.

There are same other devices that do some of the things we need, but there is nothing we know of that does everything the GT-31 can do.

My advice is to get on to your retailer and put your orders for that second, third or spare GT-31 in now!

If Locosys are not intending to produce an updated version of this device, (and I think they would have mentioned this if they were), I am certain other devices will eventually come along to meet some, or even all of our needs, but there is nothing else at the moment and it will likely take quite some time for these alternatives to become available.

lao shi
WA, 1194 posts
13 Aug 2013 7:48AM
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I know nothing about the logistics / cost of this but some thoughts...

Is there a way the GPS community can do a crowd funded approach to getting a new unit put together?
Locosys obviously have the knowledge of how to put a unit together and GPSSS know what we want / need.
I am guessing that phones have killed the low cost portable gps unit market hence no intention from Locosys to build a replacement.

Could we work with the Xensr.com crew to get an accurate GPS chip in their phone case design? Battery life is an issue here at 4 hrs.


From my understanding the GPS chips in phones are not doppler data with 1 Hz (are we the only ones that need this?) but it seems really difficult to find this out on the Interwebs.

Is there a way we could use the rasberry pi model www.raspberrypi.org/ of a bare bones device that could be home built in to a case / display to keep costs down?

Windxtasy
WA, 3871 posts
13 Aug 2013 10:09AM
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Has anyone contacted Locosys to ask what their intentions are regarding making another model or phasing out GPS units entirely?

As I have found, taking mobile phones out in an aquapac is hazardous. I have drowned 3 (whereas the Locosys GPS survived in two of those instances). I would not want to be using a phone based GPS.

sailquik
VIC, 4626 posts
13 Aug 2013 7:32PM
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We have asked and it seems that the issue is that the Sirf3 GPS chipset that is used in the GT-31 is being discontinued by it's manufacturer and superseded by other Chip-sets including, presumably the Sirf4.

Locosys says they are searching for other suitable chip-sets and if possible will continue production with another chip-set.
There is not indication so far as to whether the Sirf4 chip is suitable and/or easily integrated into the device as happened when the Sirf2 chip (GT-11) was replaced with the Sirf3 (GT-31).

I have also submitted a dream wish list for a new GPS on behalf of the WGPSSRC in particular and the GPS windsurfing movement in general that includes:

1. A gps chip capable of outputting raw binary data including Doppler speed dilution of precision which we need for the accuracy calculations. Preferably at 10hz.

2. Wrist mount is not really that useful. It is a part of the body that is quite mobile and had more vibrations. If not head mounting, the upper arm is next best, so if it was made with a long strap that goes around the Biceps, that would be good.

3. Definitely better waterproofing! Highly desirable to a much higher standard that the current devices.

4. Floatable.

5. Support for easily removable internal Micro SD card. Capacity supporting over 2gb! with modern cards that will not be superseded soon. It is getting more difficult to source <2gb SD cards.

6. Large, easily read screen with all the current Genie features

other desirable:
- Wireless downloading of data would be excellent.
- Way out on the edge would be real time transmission of data to a central data base on the shore.
- Wireless charging of batteries?



sailquik
VIC, 4626 posts
13 Aug 2013 7:47PM
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Select to expand quote
Windxtasy said..

I would not want to be using a phone based GPS.


+1 !!!

Far too expensive and vulnerable!

andersbq
61 posts
16 Aug 2013 5:43PM
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I have had contact with Locosys;
"We will have new product very soon, but I think it can not be the replacement exactly.
The target application is for hiking user and it is not suitable for using in Kite-surfing or windsurfing players.
I am sorry to let you know this.
However, if we have any update news about product can using in Kite-surfing or windsurfing , I will let you know immediately."

seanhogan
3033 posts
16 Aug 2013 7:43PM
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Select to expand quote
sailquik said..


Windxtasy said..

I would not want to be using a phone based GPS.



+1 !!!

Far too expensive and vulnerable!



been using my sony active and now sony go for over a year, without any extra waterproof casing, never had an issue (both rated IP67), as for expensive they're worth 200 $ and shock resistant. Not doppler though, so I can't enter the gpstc comp

boardsurfr
WA, 790 posts
18 Aug 2013 2:47AM
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Has anyone tried the FlySight (www.flysight.ca/)? It is u-blox 6 based, logs at 5 Hz, and apparently uses doppler speeds. Pricier than the GT-31 ($250 US), no LED, not waterproof - but variable-tone audible speed feedback that could be quite useful, and 5 Hz doppler should give better accuracy. Should be easy to keep it safe by double-bagging with a ziplock bag and a waterproof armband. I just contacted the manufacturer about getting one, but was curious if anyone has tried it already.

boardsurfr
WA, 790 posts
18 Aug 2013 4:46AM
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I got a couple of replies from Michael, the developer of the Flysight, right away. One neat thing about the unit is that the firmware is open, so modifying it should be comparatively easy. He also mentioned working on a firmware version that announces speed, which would be cool. I just ordered a unit. Should be a week or so until I get it, and maybe a few more days to test it.

Pocky
1 posts
18 Aug 2013 5:31AM
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If they would make a wireless chargeable device, with Wifi or Bluetooth, it would be possible to make it fully waterproof, since there is no requirement anymore for the SD slot.

decrepit
WA, 9159 posts
18 Aug 2013 7:24PM
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Select to expand quote
seanhogan said..


been using my sony active and now sony go for over a year, without any extra waterproof casing, never had an issue (both rated IP67), as for expensive they're worth 200 $ and shock resistant. Not doppler though, so I can't enter the gpstc comp


Although doppler is preferred, it's not a must.
You cab still enter the Gpstc as long as you can extract the file from your device so somebody else can check it, if they ever feel like it.
I think the time interval between samples shouldn't be over 2 sec though, 1sec is also preferred.

There's a little box where you post that indicates whether you're using doppler or not. This lets other people know how reliable your data is.
Of course if you get near to the top of the table it's not considered good form to be using trackpoints.

seanhogan
3033 posts
18 Aug 2013 7:40PM
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had a chat with Master Lao Shi, and he said no.... something to do with the interval maybe.... never mind I'll be my own team and captain !!!

Still got room before I get to the top of the table me thinks.....

decrepit
WA, 9159 posts
18 Aug 2013 9:19PM
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Just googled this.

Select to expand quote

dont buy the XPERIA GO if you wish to use an accurate GPS.
I have bought mine because I wanted to track my rides.
but it is way to inaccurate and non-useful:
it takes more then an hour to get a fix,
even when stationairy under an unblocked sky.. it gives me 13 km in half an hour.. with a mx speed 137 km/h.
it loses track all the time
I 've sent it back to sony TWICE!!! nothing changed.
I ve the latest version (build 6.1.1.B.1.54) ... only slightly better.

seanhogan
3033 posts
19 Aug 2013 5:04AM
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I just googled this :

Bjorn D said..

Select to expand quote

I got 26.8kts at the end of a session when I was tired doing 1 run on a borrowed GPS last year.. Can't get over 26.2 in ideal conditions this year.. Hoping mine is underreading.. I can't believe Sean was so fast on the water, it must be his mobile phone that's faulty !!!


I guess you can come up with bad/negative comments on the internet about anything, never had issues with my phones, they log on real quick and never loose the signal.
Saturday I was sailing side by side with a guy using a gt, we compared our speed on the run and they were identical....

Don't get me wrong Decrepit, not trying to convince you to allow me in the challenge... I'm fine on my side of the ocean.

Just saying that I can't see the point of using a costly non waterproof device (and it seems most of you guys use 2 or 3 at a time in case one bugs !) when I can check my tracks and speeds on KA72 (great job Dylan !) with my little real waterproof phone that fits in my impact vest and also use it to call someone if I was in trouble at sea.

cheers

lao shi
WA, 1194 posts
19 Aug 2013 8:58AM
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Just to be clear, I had a look at a data file from Sean's phone. The problem was not just the interval which is set at auto.
The peak speed may well be accurate but the data has big gaps and speed changes in it that make it unreliable for other categories.
If you have a look at the GEarth overlay you will see that the track is very jagged compared to the smooth lines of a regular track particularly in turns.





A lot of the time it is recording at one second intervals but speed varies by about 2-3 knots and the direction by 5-6 degrees
Regular 10sec vs phone


Regular alpha vs phone




I am not passing judgement on the phones just applying the rules as they stand.

The following GPS's are considered valid for the purposes of the challenge (most preferable at the top, least preferable at the bottom):

NAVI GT-31 (uses 1 sec recording intervals)
NAVI GT-11 (uses 1 sec recording intervals)
Garmin Foretrex Series
Garmin Gecko Series
Garmin Edge (1 second setting)
Garmin Legend Cx (1 second setting),

Other GPS units can be approved by the technical advisers of the challenge. All software should be set to "Doppler if available" for all categories.

Maybe there can be some discussion on this point.

boardsurfr
WA, 790 posts
19 Aug 2013 11:24AM
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I compared GT-31 accuracy to my Android phone a couple of years ago (boardsurfr.blogspot.com/2011/11/gps-accuracy-gt-31-vs-android-phone.html). The phone was fine most of the time, but it had problems similar to what Lao Shi describes above. The phone tracks also had a few minor spikes that overstated the speed by a couple of knots. That's a reasonably common occurrence even with GT-31 positional data. Every now and then, someone in our team gets excited about a high speed shown on the GT-31, and does not understand why the speed "goes away" in the software analysis. I have made myself quite unpopular by pointing such things out a few times.

To really compare accuracy between different GPS units, you'll need to have both units close to each other (ideally in the same armband), and examine the speed tracks carefully. But just for fun and use with apps like GPS Speed Talker, phones are fine.

sailquik
VIC, 4626 posts
19 Aug 2013 11:21PM
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Boardsurfer:

Thanks for bringing the FlySight device to our attention. I have done some quick reading on their website and it appears that this device might be able to be turned into something that would be very good for speed sailing.

It appears that it logs the raw binary GPS data which includes the accuracy information so that is a big tick.

The battery life @ a couple of hours is too short but that may be able to be dramatically improved with a larger battery. We really need at least 24 hours, preferably 30 or more for distance records and for multiple session where recharging between sessions is not an option.

It would appear to be a simple matter to make a completely waterproof case to enclose this box, or just use something like an existing commercial waterproof enclosure. (Otterbox?)

Being able to customize the firmware could be a huge advantage in optimizing the device for windsurfing use.

I am contacting the manufacturer to find out what options we may have in adapting/adopting this device or something based on it for speed windsurfing. Please let me know if you know of any other useful or interesting information you receive.

BTW. I read you analysis of Jibe speeds using GPS and your finding were very interesting. You confirmed much of what I found from my testing but I had not picked up on the influence of the radius of the Jibe. The other major difference I found was that the positional data was much more subject to 'spikes' and errors during the sail flip stage if the jibe. It is still present sometimes in the Doppler data but is much less common. 5hz or 10hz Doppler data with appropriate attention to 'filters' could be very much more useful and accurate, especially for Alphas.

----------------

"The older I get, the better I was".


KevinD002
226 posts
25 Aug 2013 10:22AM
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Select to expand quote
lao shi said..

Just to be clear, I had a look at a data file from Sean's phone. The problem was not just the interval which is set at auto.
The peak speed may well be accurate but the data has big gaps and speed changes in it that make it unreliable for other categories.
If you have a look at the GEarth overlay you will see that the track is very jagged compared to the smooth lines of a regular track particularly in turns.





A lot of the time it is recording at one second intervals but speed varies by about 2-3 knots and the direction by 5-6 degrees
Regular 10sec vs phone


Regular alpha vs phone




I am not passing judgement on the phones just applying the rules as they stand.

The following GPS's are considered valid for the purposes of the challenge (most preferable at the top, least preferable at the bottom):

NAVI GT-31 (uses 1 sec recording intervals)
NAVI GT-11 (uses 1 sec recording intervals)
Garmin Foretrex Series
Garmin Gecko Series
Garmin Edge (1 second setting)
Garmin Legend Cx (1 second setting),

Other GPS units can be approved by the technical advisers of the challenge. All software should be set to "Doppler if available" for all categories.

Maybe there can be some discussion on this point.



Lao,

Would you still recommend setting the ForeTrex 301s/401s to 2second interval?

Thanks!
-Kevin

lao shi
WA, 1194 posts
25 Aug 2013 10:33AM
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Having had a quick look online (not familiar with these devices) those units appear to be able to record at 1 sec intervals and should be set on 1 sec.
From memory the original Garmin's had the option of 2sec or Auto and so the advice was to set at 2 sec.
The problem with some of the phones is that there is no option to force a 1sec interval and the phone conserves its resources by not recording data points when speed is uniform or below an arbitrary threshold.

KevinD002
226 posts
25 Aug 2013 11:05AM
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Alrighty! I have left it on 2 sec for the longest time but felt like 1 sec would work as the numbers on the FT401 were very VERY similar to my GT-31.

Thanks!
-Kevin

mathew
VIC, 1730 posts
26 Aug 2013 9:59PM
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Select to expand quote
KevinD002 said..

Alrighty! I have left it on 2 sec for the longest time but felt like 1 sec would work as the numbers on the FT401 were very VERY similar to my GT-31.

Thanks!
-Kevin


1-sec is better / more-accurate, but the 401 has only 10,000 points storage -> which limits you to just under 3 hrs.

KevinD002
226 posts
27 Aug 2013 2:45AM
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Due to the gusty nature at my location and a nagging spouse I can only usually go for 2 hours so I'm safe!

boardsurfr
WA, 790 posts
28 Aug 2013 4:27AM
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I got the FlySight GPS today. The unit is so small that adding an external battery pack for longer runtimes is no problem. Just missed being able to test it in yesterday's great wind, but did a little test on my bicycle that looks promising:

The positional tracks look much better. Both track-based speed plots have major spikes that are absent in the Doppler speed plots. The GT-31 data show a false huge drop in speed whenever I drove around in a circle - the same artifact that understate speeds in jibes with a narrow radius. In this test, the FlySight looks a lot better than the GT-31. But the comparison on the water is what counts, and it will be a few days before we get wind.

Michael, the FlySight developer, has been very helpful. Within an hour of sending him an email that the regular .csv format was not very useful, he sent me a custom firmware that writes binary .ubx files, which GPSAR Pro should be able to read directly. Nice!

decrepit
WA, 9159 posts
28 Aug 2013 10:50PM
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That does look very promising, maybe I can get a 25doppler alpha with it.



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Forums > Windsurfing   Gps and Speed talk


"About GT31 EOL" started by b14