Quick GPS fix?

[dash8]

Anyone know what's happened to QuickGPSfix on Tomtom Home? It's been missing for weeks, and my XL340 seems to take longer to find a signal each time its turned on.

 

[canderson]

Anyone know what's happened to QuickGPSfix on Tomtom Home? It's been missing for weeks, and my XL340 seems to take longer to find a signal each time its turned on.

Chances are you picked up a corrupt one. The "live until" date is part of the data in one of the files, and if goofy, can prevent another from ever being loaded.

Easy remedy - nuke 'em all, reconnect, and you'll be good to go.

On your 340, in the root directory, you will find a folder called "ephem". That folder will contain a *.tlv file, a *.txt file, and a *.dat file. Delete all three of those files.

On your PC, in the folder My Documents/TomTom/HOME/Downloads/complete/ephemeris, you'll find a bunch of subfolders called QuickGPSfix. Delete all of those subfolders.

Hook up with Home, and you should get a new fix update.

 

[dash8]

I've had failed downloads before, but this wasn't even showing up on the menu. Anyway, it's downloading again now. Thanks.

My *.dat file on the XL340 was missing altogether. Perhaps that was the whole problem.

 

[canderson]

I've had failed downloads before, but this wasn't even showing up on the menu. Anyway, it's downloading again now. Thanks.

My *.dat file on the XL340 was missing altogether. Perhaps that was the whole problem.

Probably so. And no, it wouldn't even show up on the menu - but that would happen immediately following a problem with one of the files you picked up from a previous download. Once you get a 'bad' file, the date comparison (today vs.when the next download should occur) blows up, and it stops even offering them.

Glad to hear you're getting them again.

 

[nicemann]

Chances are you picked up a corrupt one. The "live until" date is part of the data in one of the files, and if goofy, can prevent another from ever being loaded.

Easy remedy - nuke 'em all, reconnect, and you'll be good to go.

On your 340, in the root directory, you will find a folder called "ephem". That folder will contain a *.tlv file, a *.txt file, and a *.dat file. Delete all three of those files.

On your PC, in the folder My Documents/TomTom/HOME/Downloads/complete/ephemeris, you'll find a bunch of subfolders called QuickGPSfix. Delete all of those subfolders.

Hook up with Home, and you should get a new fix update.

Thank you, I was having the same problem and your fix worked for me. Greatly appreciate your advice!

 

[gatorguy]

GPSQuickfix via TTHome needs to go away. Period. The only reason it exists is to strongly encourage owners to connect to the servers frequently so that trip stats can be harvested. No other manufacturer requires a computer connection to supply updated ephemeris data that nearly all others compute on the device itself. In fact on-board automomous Quickfix is so ubiquitous, I suspect Tomtom is actually disabling it on their chipset. I'd wager that it's there and has been for some time.

 

[canderson]

Could be a legacy issue. The SiRF III chipset didn't support HotFix (Garmin's name for it) technology, so the earlier Garmin units and earlier TomTom units (e.g., GO730 and others built 2008 and prior) couldn't perform that function.

The GL2 chipset currently preferred by TomTom can manage it, though, and there's no excuse for using the QuickFix on those.

 

[gatorguy]

The SIRF III did in fact support Hotfix. That's the chipset used as early as 2007 in the Garmin 7x0 series. Garmin enabled the function with a firmware update in early 2008.

 

[canderson]

The SIRF III did in fact support Hotfix. That's the chipset used as early as 2007 in the Garmin 7x0 series. Garmin enabled the function with a firmware update in early 2008.

I believe that the "Hotfix" firmware update applied ONLY to Garmin units that employed the MediaTek GPS chipset, not the SiRF III - which is why quite a number of previous Garmin models were not candidates for this update. I believe the units with STMicro chips were using something called Networks GPStream (it's been a while, so don't hold me to that name).

Garmin was all over the map with chips for a bit. STMicro, MediaTek and SiRF.

The older SiRFIII chip units could still benefit from the SiRF SiRFInstantFixII (extra per unit license cost, of course) -- but I don't think Garmin ever released a version that for their SiRFIII units.

 

[gatorguy]

My old reliable nuvi 760 has a SIRFIII chip. And InstantFix. The actual autonomous fix function was added to it via a firmware update months after I had purchased it in Nov/07. Thus the chipset supported it from day 1 even tho the software to make it function wasn't yet ready.

 

[canderson]

There were some older Garmin units (I'd swear they were SiRF based) that never got the InstantFixII update. I remember just as people were becoming aware of what it accomplished that the owners of those units were moaning about not getting the benefit of the technology. What was that about?

 

[gatorguy]

There were a few MTK-based units reported by owners if I remember accurately. Those were later releases, not showing up until after the InstantFix update had been rolled out to the existing devices. By then I think Garmin was referring to those with out-of-the-box autonomous fix as having InstantfixII. But don't hold me to that one. Memories can be a mysterious thing. But even MTK now offers the same function, as does Broadcom, Infinion and Ublox to the best of my knowledge.

 

[canderson]

I'm reasonably confident that the SiRFIII equipped units were NOT the target for the upgrade that first came out that Garmin was calling HotFix. When Garmin released that firmware update in 2008, it was for these models:

205, 205w, 255, 255w, 265T, 265WT, 275T (STMicro, Cartesio chip)
500, 550 (ST Micro, Cartesio chip)

750, 760, 770, 780 (a few early units were SiRFIII, but all production after summer 2007 were MediaTek MTK3318 chips)
755t, 765t, 775t, 785t (MediaTek MTK3318)
850, 880 (MediaTek MTK3318)

The fact that your particular 760 supported the original Hotfix update would have been because it was produced after the changeover to the MTK chip. Only the earliest production 760 (or 770) would have had the SiRFIII chip.

 

[gatorguy]

Canderson, my 760 doesn't have MTK, so of course doesn't have Hotfix, a solution for the Cartesio/Bravo chipsets. Mine is absolutely SiRFIII. And it's a 760, purchased 11/07. And has Instantfix. Every 7x0 sold thru Nov.2007 was sporting a Sirf chipset to the best of my knowledge, with Instantfix enabled thru a firware update in very early 2008. Those "Bravo" chipped MTK's didn't get thrown in the mix till very late in 2007, early 2008

One old reference thread: This is how to find what chip is in your 7xx GPS - Garmin Nuvi Forum

 

[gatorguy]

Here we go. My memory was basically good, just a little fuzzy on the details.

SirfI initially announced Instantfix back in 2006. Available on the SirfstarIII chipset, it required that you connect to the internet to download an updated ephemeris file. TomTom began using it withe the x20's in 2007, but referred to it as Quickfix. The revised Sirf version, offered as InstantfixII, first appeared on a pnd in January 2008 via a firmware update for Garmin's 7x0 series, tho it was already in use for some HP PDA's apparently. TomTom chose not to enable InstantFixII, instead clinging to the older version that required a connect to TTHome.

Garmin's "Hotfix" feature is generally identical to InstantFixII, but applied to the MTK chipset in the "newly announced" 2x5's and 7x5's in August of 2008. I don't think MTK chipsets started appearing in the 7x0 models until summer of 08. Of course Garmin didn't help with chipset confusion back then, with some CSR's claiming the 7x0's never used SirfIII chips. They were mistaken. No owner of one found anything other than a SirfIII chipset inside until May of 08 (I think. ).

Sirf Quick/Instant fix primer - GPS Discussions
Garmin Announces Nuvi 2x5 and 7x5, Free Lifetime Traffic, Lane Assist, 3D Transparent View (GPSmagazine.com)

 

[canderson]

That speaks to a considerable inventory of the 7x0 units being built up if the MediaTek units didn't start to show up until the summer of '08. How the CSRs could say they never used SiRFIII though. Well, we know how up-to-date CSR information tends to be (ala TomTom).

Finally found the old reference document. Wow - this is like digging through the sands for artifacts. The InstantfixII update was supposed to have come as part of the 2.6 updates to the Nuvi line, and was evidently rolled out on about the last day of January of 2008. That's the key - is the above correct? The original release notes moving from 2.5 to 2.6 never even mentioned it, and when CSRs were asked what the new notice was on the front panel during boot, they had no idea. (Sounds more like TomTom than TomTom!)

If correct, then the InstantFixII 2.6 update did predate the HotFix solution which I'm sure came out in late August of 2008. Color me confused, though. When Garmin announced the HotFix program, it did so as though this was a "first" for them, and no mention was being made of the fact that the InstantfixII had already been released for the SiRFIII units. What I am completely unable to sort out is why both Garmin and the reviewers saw HotFix as some kind of new and amazing technology - as though Garmin had never previously addressed this issue on other chipsets. PR hype?

As to the issue of chipset confusion: Here's an example of commentary from a review posted when HotFix was being released in new models:

"Garmin is also touting a new feature called "Garmin HotFix", which sounds exactly like SiRF's InstantFix, a feature that improves start-up time and lets the GPS almost instantly determine your location (provided the GPS has been turned on within the past 7 days). If Garmin's HotFix is really a re-branded InstantFix, that's very good news indeed, as it's a good sign they're using SiRF's high performance GPS chipset." (see Garmin Announces Nuvi 2x5 and 7x5, Free Lifetime Traffic, Lane Assist, 3D Transparent View (GPSmagazine.com) ).

As you can see, even the reviews had it completely screwed up. We know that the above paragraph is pretty sorely confused. However, it indicates (as did many articles when HotFix was released) that it was believed that SiRFIII chips were still being used. This particular article was written in August 2008.

Of some inerest, HotFix had already been announced for Garmin's new handhelds in July of 2008, predating the Nuvi announcement as far as I can tell.

 

[gatorguy]

Yup, I think you got it on the Garmin 7x0's and InstantfixII. The whole thing was confusing to say the least. But getting back to my original comment, there's no reason other than data harvesting for TT not to offer autonomous fix computation like every other manufacturer of pnd's, most of them since 2008. But having said that, I suspect they might have with the latest 2xxx models. I think GPSQuickfix via MyTomTom might be just smoke and mirrors, with the device itself computing the actual data. No solid evidence of this tho, just some general user comments of faster sat lock times compared to the last gen models.