REVIEW COMMENTS: SysOnChip CF Plus GPS

Dave

orrett, judging by the comments here and in the email you've sent me, and failing to identify which driver you are using as requested above, there's very little I can help you with.

What I can say is again I have tested the SysOnChip CF Plus today with TomTom Navigator 2 and I have had no issues in it lagging behind or indeed ahead under normal use. The only time I could cause it to jump ahead when I was stationary was to decelerate extremely quickly from 70mph to 0mph within a very short distance of road, and this jumped me onto a roundabout when I was waiting at the roundabout, and this isn't normal behaviour (or shouldn't be).

Again I'll ask you which driver are you using ??? If you're using SiRF, switch to NMEA! I can't tell you what version of TTN2 I was on when I reviewed this, but the Pocket PC I have again tested it on today and shows the same results to my review is V2.00 265/330 running NMEA 0183v2/4800/SysOnChip CF_GPS_Receiver. TomTom do on a very regular basis implement bugs into newer versions of their software and this can cause problems with certain hardware, or show up other issues even more so. We also tested the SysOnChip CF Plus with Navman SmartST Pro and this found no lag either.

SysOnChip CF Plus does come with SiRFXTrac, which is designed to bring in greater sensitivity in signal to help obtain fixes where you normally wouldn't be able to, and this can create a lag when accelerating or decelerating quickly, but on the model I have here I am only seeing this when trying the extremes. Travelling at 40mph decelerating to 0 or even staying at constant speeds I'm not seeing any lag. Today I had a SiRFII/e receiver on a 2210, and the SysOnChip CF Plus on another 2210, both operating at the same time, both showing identical positioning both with each other and to the road.

As many will know who read the website regularly, some of the GPS Receivers we receive aren't always production models, some are pre-production models and also some are from the first batch run form the factory, GPS Manufacturers do change their products sometimes between batches to enhance or rectify faults, and it maybe that you have a later firmware verison to the one we have here.

Dave

Chorlie, where are you seeing the time lag mostly ? In accelerating, decelerating or constant speed ?

I would try dropping back to the main 2.0 GPS driver as this doesn't exhibit the problem for me accept for under extreme circumstances.

bennyblanco

well thats cheered me up, ever optimistic as I am, i will give it a go before i knock it Smile

Dave

Bennyblanco, I'd like to hear properly from people who are experiencing the lag to find out how bad it is, and which drivers they're using within TTN2. So far I haven't received that information. It wouldn't be the first time that we've received a pre-production model, or a model that was production, but the spec has changed since.

Unfortunately like other review sites, we only usually get one piece from the manufacturer or retailer, so we can only report and review on the gear that has been sent to us, and the card I have here is very good. I'd love to be sent a batch of each GPS Receiver over a period of time and watch how it changes. If anyone wants to send me their SysOnChip CF Plus for a week to test and compare with the one I have here, send me a private email. In the mean time if people can tell me what configuration they have, whether they're using NMEA or SiRF, baud rate and which driver version of the GPS Driver, I might be able to offer some assistance in reducing the lag, or confirming it here.

bennyblanco

Cool Dave, when it arrives I will do. Must admit though, at present I dont have a clue what you are tlaking about Smile

hehe, NMeA, SiRF, eek!

I'm sure it will become apparent. So will let you know.

cheers!

Ben

orrett

OK
O have establiehsd that I am using 2.08 drivers and 2.24 software. The LATEST on the website.

Ever ready to be proved wrong I have just driven across town.

A typical scnario happens outside my drive "turn left 50 yards then turn right. I do so, then after I have turned left and got to the right turn it tells me to turn left. Because it does not realise I have turned already.

As a test I drove up to the junction and stopped the map carried on moving for a good five seconds and then. Similar things happen at roundabouts. It gives me instructions after I have passed them by.

Again, a right turn stright on. Sudently about 200 yards on it tells me to take a right - Down a culdesac.

Sorry , it is just not reliable. Happy to try the version two driver - but sounds to me like you are grasping at straws!!!!.

Paul

orrett

Just got this from the manufacturar. Clearly it is a know problem.

Hello.

Thank you for purchasing our " SysOn GPS CF Plus ".

I saw your indication for our GPS receiver problems.

First of all, our GPS receiver had equipped SiRF XTrac software.

Currently, SiRF XTrac software have some problems of slightly point delay.

But, you can solve the problems somewhat.

You had better to change the SiRF binary protocol for better performance.

Finally, please send me a product Serial number( back of the product, for example

S/N : 03062601430 )

I will check the your product spec.

Thank you for inquiry.

Buy!!!

SysOnChip, Inc.

GPS Division, Manager

Dong-yong Lee.

I will try what they suggest, but even they do not sound too convinced it will make much diffrence.

NOW will you change your review so that people like me and others are not mislead by your eulagising about this product??

Paul

DavidW

The issue of SiRF Xtrac firmware causing lag is one that's been pondered at length on the Internet. I can only recount what I've read elsewhere, as I've no personal experience of Xtrac based GPS.

Some find the lag (which, I understand, affects speed and direction information more than the position) unbearable. Others say they don't notice it and can't find it in their application!

It seems that big changes of speed and direction cause the most lag - hence the reports that some have struggled with Xtrac receivers for inner city in-car navigation because of the frequent turns. This is an application for which extra sensitivity is clearly useful.

My personal suggestion would be to mark the original review as saying that the great signal performance is due to Xtrac firmware, and that there may be "lag" issues under some circumstances.

Xtrac firmware also explains why SBAS (the generic term for WAAS, EGNOS and similar systems) can't be selected - my understanding is that the Xtrac firmware affects the configurability of the unit. Early reports were that SiRF binary mode couldn't be selected, but they appeared to be in error and I believe it has been found that Xtrac based units can be reconfigured to some extent. I wonder if it's simply that either code size or CPU usage mandated the deletion of SBAS support from the Xtrac firmware.

It would also seem worth checking with SysOnChip as to whether all units have Xtrac firmware. Some manufacturers that offer Xtrac units offer a choice (Haicom HI-303MMF is standard SiRF firmware, HI-303S is Xtrac - and, for what it's worth, HI-303E is non-SiRF, an Evermore chipset; Holux GM-270 is standard SiRF firmware, Holux GM-270 Ultra is Xtrac).

It could be that the particular item reviewed (and which people have bought) has optional Xtrac firmware - Xtrac firmware is not specifically mentioned on the SysOnChip web site here.

When Xtrac first came out, I decided it was for me, but eventually decided that the extra cost and possible lag wasn't worth it. Eventually I bought a Haicom HI-303MMF with standard SiRF firmware.

Finally - to Paul O - if you believe the GPS is so bad as to be not fit for purpose, I suggest you talk to the supplier about returning as not fit for purpose. Suggesting that Pocket GPS pay you compensation seems fanciful - considering that this site is put together by enthusiasts who charge us nothing to use it. On this site, we are able to discuss reviews.

There's a little lag even with a standard SiRF GPS - and the behaviour you describe in TomTom Navigator 2 is normal even with a standard SiRF GPS.

GPS accuracy is not perfect. The US Government specification allows sufficient errors in the Standard Positioning System (all we can use - the Precise Positioning System is encrypted and its use restricted to authorised users only) that techniques such as snapping the position to the nearest road (using the direction of travel as a clue) and assuming the planned route is followed are still needed. SPS performance since Selective Availability was switched off a few years back is usually excellent, but it doesn't give a position precise to a couple of metres (a few tens of metres is more like it if you want decent confidence in the position).

Positioning becomes a particular challenge in cities with a poor view of the sky - that affects the accuracy of your position fix. Using a conventional SiRF firmware receiver, I have once seen Navigator 2 hop to an adjacent road when stationary at traffic lights in Central London. At that time I only had a relatively poor 3 satellite fix.

If you take a different turn to that that Navigator is expecting you to, it will dither for a second or two (the GPS hardware only provides a position, speed and direction update every second). If you watch the map as a passenger, you'll probably see the arrow enter the route Navigator thought you were taking (probably still pointing in the actual direction of travel). Eventually it realises that you haven't followed the route it was suggesting and reroutes you accordingly. It appears to be precisely this behaviour you are describing - if so, that's Navigator, rather than the GPS hardware.

GPS can be tricked. Expensive in-car systems often use inertial techniques as well to provide a double-check of GPS information. You're talking there, though, about systems costing thousands. I find GPS-only in-car navigation to be an excellent tool - though I accept it has limitations.

David

orrett

Hi David

A very informative response. Thank you. First reread what I said. NOWHERE have I implied that I wanted compentation from the website. Indeed I made the firm point that I make my own decisions and accept responsibility for them. My point was that if the website persists with this false and misleading review now that evidence to the contary has been provided then they should expect others to expect compensations.

I think its pity that the site has not come clean about the product sooner. Its not hard to say "Sorry we got it wrong". I have spent a lot of time chasing this matter and, despie daves comments the manuafacurer has now admitted it is a know problem. From your own comments this has been known for some time. So how can the product get a ten on ten for every aspect of its performance? Somthing designed to give you direction is no good if it tells you to turn right fifty yards after the turning. Actually its quite dangerous.

The manufacture suggested changing for nema to sirf and has sent to a utility to do so. Just been trying for twenty min and it just defaults to nema or what ever.

the bottom line is that as a user I only want the thing to work, and when I get advice from websites like this I listen. I am indeed pursuing a refund and will source a product that works, again your posting is helpful in that respect. However, fanciful I am not.

On a final point, when you buy somthing it should do what is says on the box. just cos its complicated technology makes no diffrence. Consumers should stand up an say we want honesty, not hype. I do am doing just that and I hope it makes people think twice before trusting this review. It is too late for me - but not for others.

Best wishes

Paul

orrett

Other evidence that others consider this "chipset"? a problem

http://www.gpspassion.com/forumsen/topic.asp?TOPIC_ID=1922

Those of us with problems are not alone, nor is this issue "new information". The conclusionof this long thread is that this is not a good tool for car navigation. Indeed on another forum on your own website the problem is alluded to. Yet you give it ten out of ten.

bennyblanco

ALso Odd, the dude on gpspassion claims its impossible to switch from xtrac to sirf, but the website:

http://www.sysonchip.co.kr/eng/prod/pro_gps_3.htm

Says you can? Surely if you can't, then they are breaking trade description or something.

And seeing as i know nothing, does SiRF actually make anything faster (does it turn this xtrac off or something) and why is it not on by default?

Ben

orrett

Like you i know nothing about sirf. I though you used it to wash clothes. However, I have tried to switch from nema to sirf using the utility the guy from syson sent. It wont buy it. At best it defaults to nema at worse it locks up.
Paul

bennyblanco

Well OK, have managed to sell mine before it arrives Smile

I will still test it, although i am guessing mine wont be much better.

Question then, which one would be recommended in its place? Non bluetooth and not over £150?

Dave

Paul,

You say "I think its pity that the site has not come clean about the product sooner. Its not hard to say "Sorry we got it wrong".".

Geez, there's just no helping some people!!! I will re-iterate what I said. Are you listening ??????????

In the 4 week test period we had, it didn't exhibit a single problem whatsoever. So what shall we come clean to ? Geez! I'm sorry, but I can't come clean to something with the SysOnChip CF Plus that I didn't experience when reviewing the product, nor witnessed.

Our reviews are very factual, based on an extensive 4 weeks test of the product. If it had exhibited lag at any point, I would have been all over it in the review. Again, it didn't, so I can't own up to something I didn't experience.

The SysOnChip CF Plus we have found out since does use SiRFXTrac (nothing was on their website or in the box) and we have found that out from SysOnChip themselves, and yes there is some performance lag that SiRF say "may" occur, but again, SiRF say that it won't occur all the time, and it's something we didn't experience. We will be amending the review to say it uses SiRFXTrac rather than SiRFII/e and do have an article coming out to explain XTrac in more detail.

However, I've asked you twice now for details of the settings you are using, I have one working here without lag, don't you want to try these ? No, course not, you say the product must be faulty. Well sorry, can't help you much here if you're not willing to help yourself a bit. Many people have had issues with GPS Receivers which all appear to be faulty in some fashion, and we've helped through configuration overcome these problems. I've offered you help and advice here, but if you're willing to ignore it just for the sake of doing so, then I can't help you anymore.

orrett

errm Dave, I sent the setting (2.08 drivers and 2.24 software) a few emails back.

I am sorry you feel afronted, and I am glad you are making a small amendment to the review. I suggest we leave it there. I do appreciate the time you put into things like this and I wish you well. Naturally, if you feel that my contributions have no value or are misleading then please feel free to remove them from your website and delete my registration from your forums. For my part I will keep away from your website from now on.

Best wishes

Paul

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