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archibald
7 Posts |
 Posted - 12 déc. 2007 : 22:55:14
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| yea i saw that but wasn't sure what you meant. does it mean there's no way of knowing which fw version i have? |
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gpspassion
93402 Posts |
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archibald
7 Posts |
Posted - 12 déc. 2007 : 23:05:49
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| i see. thanks for clearing that up. from the limited testing i've done today it would seem like it's the recent version. accuracy on foot seemed ok with mgmaps |
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musky
USA
226 Posts |
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archibald
7 Posts |
Posted - 13 déc. 2007 : 20:23:06
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hmmm well i must admit a lot of your post went straight over my head :D
how exactly does this Low Speed Bug manifest itself then? you mention "the characteristic of not reporting a speed after having been still for a couple minutes". i haven't noticed anything like that but i only got it yesterday and have hardly used it yet. the only thing i have noticed is the fact it shows a speed of 0.2-1.2 km/h even when i'm sat still inside my house. is that normal or is that caused by the LSB?
i went for a short walk with mobile gmaps yesterday and the only things i noticed were that it took a while for the position to update and the compass seems to have a bit of a hard time maintaining a heading at walking speed. are these also telltale signs of the LSB? |
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Bartman_x50v
42 Posts |
Posted - 13 déc. 2007 : 22:05:59
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hi
somebody know the B-core_1.1 0004 fw??
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Edited by - Bartman_x50v on 13 déc. 2007 22:06:33 |
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musky
USA
226 Posts |
Posted - 13 déc. 2007 : 22:38:43
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Hi Archibald:
For the "long winded" explanation of the LSB, see my post on page 1 of this thread, dated 3-11-07. I am seeing similiar behaviour with my brand new M1000B, although I'm not sure at this point that is exactly the same.
A GPS should normally show small variations in position when you are still. This is just due to noise in the measurement. Laws of physics. Your position is calculated every second or so, based on the delay from radio signals from satellites with known time and position.
Sirf has this feature called "static navigation" (that is usually OFF by default), where they get clever and add additional software which tries to detect if you are standing still, and then freezes the position. (Somebody correct me if I'm off base on this, I have never enabled SN on my Sirf units)
The problem in doing something like this is that if you get it wrong, you will erroneously report the position as frozen, when in fact, the unit could have moved slowly. Therefore, the selection of the "freeze" threshold and back averaging, etc. has to be done very carefully to avoid this dilemna.
When I got my first MTK unit, I guessed that they were doing something similiar to Sirf's SN, but they had messed it up and got too aggressive about calling the unit "froze".
Since then, it has been reported by Semson's and GPSPassion, that this is not an intentional SN feature in MTK units, and is in fact a bug. Hence the term Low Speed Bug (LSB).
Also, rumour has it that MTK has fixed the LSB, and firmware 1.94 or above has it fixed. Problem is, Holux uses a different versioning system, and now it's b-core 1.0 or whatever....
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rakerman
Canada
30 Posts |
Posted - 16 déc. 2007 : 17:10:01
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The GiSTEQ DPL700 ("PhotoTrackr Lite") also uses the MTK chipset (M-core_2.0)
BT747 can partially talk to it on Windows, but not download logs. |
Richard's Tech Reviews - GPS Loggers and Geotagging Photos |
Edited by - rakerman on 21 déc. 2007 18:10:02 |
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sooby77
87 Posts |
Posted - 17 déc. 2007 : 21:14:24
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| This might be old news, but the iBlue 737 I just got from Semsons has the firmware M-core_1.94,00052. It can now change the refresh rate using the software from 1-5hz. |
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gpsmatt
5 Posts |
Posted - 02 janv. 2008 : 11:27:20
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Excellent forums - I've been reading for a few days non-stop :).
I'm about to buy my first GPS logger (MTK-based). Two questions:
* What is the highest firmware version that has been spotted?
* Any suggestions when buying (eBay or new) on how to ensure I'm getting at least firmware version 1.94 or later? [I will be using it to log both 5Hz bike + ski logging, and 1Hz walk / hike logging, so avoiding the low speed issues is essential.]
TIA, Matthew |
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musky
USA
226 Posts |
Posted - 02 janv. 2008 : 13:16:13
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| In general, I think you will have better luck getting the firmware version of the unit you are about to purchase from Semsons, GlobalSat, etc. and NOT from an E-bay seller. I'm sure there are always the exceptions to this rule.... Personally, I don't use E-bay just to save a few $$'s, because I would rather deal with a professional company. In other words, on E-bay you never know the expertise of the seller. On the other hand, E-bay does have items that seem only to be avaialable there, like my first MTK USB unit. Good luck. |
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gpspassion
93402 Posts |
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gpsmatt
5 Posts |
Posted - 04 janv. 2008 : 00:06:27
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Thanks musky and passion.
Is there perhaps a make & model out there that is new enough, that I'd guaranteed to get firmware 1.94? Barring that I'll try to get the seller to look up the firmware on the device for me pre-sale. What's the easiest way to determine the firmware version? |
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musky
USA
226 Posts |
Posted - 04 janv. 2008 : 00:33:36
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The unit should have a CD that comes with it that will have a little "tool" app on it. In the case of MTK I think it's called GPSView or GPSInfo or something like that. You run that and it'll give you the firmware version. Again, if you get an E-bay seller to do that for you, my hat's off to you  FWIW, the firmware world in these mouse GPS's is very poorly documented and communicated. In an ideal world you would know your firmware version before you bought the unit, and would be able to go on a website of the manufacturer and look at the change log for the various firmware versions, but, oh no.... we can't have things that easy now 
BTW, why are you set on MTK? Why not a Sirf III? Get a Sirf III with firmware 3.2.x or greater (sorry, here we go again with firmware  ) and you will have excellent low speed performance and WAAS to boot.
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gpsmatt
5 Posts |
Posted - 04 janv. 2008 : 10:53:44
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Ideal world indeed. [These problems are not limited to the GPS space either :/.]
Honestly, the 5Hz capability of the MTKs is really intriguing to me. I believe that it will serve at least one of my applications much better than a 1Hz device. iBlue's 747 is nearly ideal (being a logger, and a bluetooth gmouse). It should save me from having to buy two separate devices. |
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* Discussing MTK receivers and Tips and Tweaks *
