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Science Forum Index » Geology - Satellite Navigation Forum » REQ: GPS-receiver (bluetooth, usb or serial)
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| Tobias Wendorff |
 Posted: Sun Mar 04, 2007 3:50 pm |
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Guest
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Hi there,
can anybody please recommend me a GPS-receiver for Bluetooth, USB
or the serial-port?
There are hundrets of different devices on the market. The chipsets
are: SiRF III, Sony, Atmel and MTK
I've read that SiRF gives the best results right now, but MTK seems
to have a high sensitivity and 32 channels for tracking satellites!
Is there any device under $100, which you could recommend me?
Best regards,
Tobias |
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| Jack Erbes |
| Posted: Mon Mar 05, 2007 10:24 am |
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Guest
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Tobias Wendorff wrote:
Quote: Hi there,
can anybody please recommend me a GPS-receiver for Bluetooth, USB
or the serial-port?
There are hundrets of different devices on the market. The chipsets
are: SiRF III, Sony, Atmel and MTK
I've read that SiRF gives the best results right now, but MTK seems
to have a high sensitivity and 32 channels for tracking satellites!
Is there any device under $100, which you could recommend me?
A good model for all around use is the SiRF III Holux GR-213. That
comes with a PS/2 connector on the cable, a PS/2 to USB adapter cable,
and you can purchase various optional adapter cables to adapt the serial
output to DB-9P hardware COM ports and various PDAs.
I have a GR-2313 and it is very fast and has good sensitivity too,
impressive for its small size. I also have the SiRF III in my Garmin
76Cx and I never cease to be amazed at the improved performance of the
SiRF III chip set over the earlier SiRF II. The SiRF III only displays
12 channels but has 20. The other 8 channels are used in the background.
The 40 channel MTK chip set sounds interesting, I wonder where that is
being used.
There is one model of the GR-213 that has only the USB connector
hardwired on making it for USB use only, I think you want the more
adaptable one that has the PS/S2 connector. Here is an example of it, I
have no experience with that seller but they look to be established and
reputable:
http://tinyurl.com/2z99ek
And here is an example of the GR-213 model I think you do *not* want:
http://tinyurl.com/2be544
I do not recommend buying from eBay seller "gps4evyone". They are
dishonest and cannot be trusted to the follow up on any sales with which
there are any problems.
Jack
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Jack Erbes in Ellsworth, Maine, USA - jackerbes at adelphia dot net
(also receiving email at jacker at midmaine.com) |
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| Tobias Wendorff |
| Posted: Mon Mar 05, 2007 7:14 pm |
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Hi Jack,
Jack Erbes wrote:
Quote: A good model for all around use is the SiRF III Holux GR-213. That
comes with a PS/2 connector on the cable, a PS/2 to USB adapter cable,
and you can purchase various optional adapter cables to adapt the
serial output to DB-9P hardware COM ports and various PDAs.
Since I want to do some logging and tracking, a PDA ist a good
solution. I never had a PDA, but some old PALMs are around $30-$50
only. I only need to find good software.
Quote: I have a GR-2313 and it is very fast and has good sensitivity too,
impressive for its small size. I also have the SiRF III in my Garmin
76Cx and I never cease to be amazed at the improved performance of the
SiRF III chip set over the earlier SiRF II. The SiRF III only
displays 12 channels but has 20. The other 8 channels are used in
the background.
I hope to get the GR-231 in Europe (I'm from Germany).
Quote: The 40 channel MTK chip set sounds interesting, I wonder where that is
being used.
Where did you see a MTK chipset with 40 channels? I only saw 32 max.
Quote: There is one model of the GR-213 that has only the USB connector
hardwired on making it for USB use only, I think you want the more
adaptable one that has the PS/S2 connector. Here is an example of
it, I have no experience with that seller but they look to be
established and reputable:
http://tinyurl.com/2z99ek
And here is an example of the GR-213 model I think you do *not* want:
http://tinyurl.com/2be544
Oh, thanks for the hint!!
Quote: I do not recommend buying from eBay seller "gps4evyone". They are
dishonest and cannot be trusted to the follow up on any sales with
which there are any problems.
I think, I have to buy it in Germany anyway. Customs, VAT and shipping
will consume much money.
Best regards,
Tobias |
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| Jack Erbes |
| Posted: Tue Mar 06, 2007 1:18 pm |
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Tobias Wendorff wrote:
<snip>
Quote: Since I want to do some logging and tracking, a PDA ist a good
solution. I never had a PDA, but some old PALMs are around $30-$50
only. I only need to find good software.
Here is a link with some PDA software, most of my experience has been on
Pocket PCs with Ozi Explorer-CE and commercial applications like Tom Tom
5. I seem to remember that the choices of software were a little more
limited for the Palm than for Pocket PCs:
that http://gpsinformation.net/#PDA
Quote: I hope to get the GR-231 in Europe (I'm from Germany).
That is the Bluetooth model with the same excellent chip set. I've
never messed with Bluetooth GPS.
Quote: The 40 channel MTK chip set sounds interesting, I wonder where that is
being used.
Where did you see a MTK chipset with 40 channels? I only saw 32 max.
You're right, I don't know where I got that number.
<snip>
Quote: I think, I have to buy it in Germany anyway. Customs, VAT and shipping
will consume much money.
You have my sympathy. But don't forget, you get better beer. :>)
Jack
--
Jack Erbes in Ellsworth, Maine, USA - jackerbes at adelphia dot net
(also receiving email at jacker at midmaine.com) |
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| Dale DePriest |
| Posted: Wed Mar 07, 2007 11:29 pm |
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Jack Erbes wrote:
Quote: I have a GR-2313 and it is very fast and has good sensitivity too,
impressive for its small size. I also have the SiRF III in my Garmin
76Cx and I never cease to be amazed at the improved performance of the
SiRF III chip set over the earlier SiRF II. The SiRF III only displays
12 channels but has 20. The other 8 channels are used in the background.
Did you just invent the 8 channels in background stuff? There are no 8
channels in background. The SiRF III is capable of running the
equivalent of 20 channels on 1 dsp in that there is enough bandwidth but
if it is configured for 12 channels then that is all there is. There are
no more channels than the ones it is configured for.
Dale
--
_ _ Dale DePriest
/`) _ // http://users.cwnet.com/dalede
o/_/ (_(_X_(` For GPS and GPS/PDAs |
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| Jack Erbes |
| Posted: Thu Mar 08, 2007 10:12 am |
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Dale DePriest wrote:
Quote:
Jack Erbes wrote:
I have a GR-2313 and it is very fast and has good sensitivity too,
impressive for its small size. I also have the SiRF III in my Garmin
76Cx and I never cease to be amazed at the improved performance of the
SiRF III chip set over the earlier SiRF II. The SiRF III only
displays 12 channels but has 20. The other 8 channels are used in the
background.
Did you just invent the 8 channels in background stuff? There are no 8
channels in background. The SiRF III is capable of running the
equivalent of 20 channels on 1 dsp in that there is enough bandwidth but
if it is configured for 12 channels then that is all there is. There are
no more channels than the ones it is configured for.
Oh oh! Now I've run afoul of an expert.
I think I am paraphrasing something that I read here. Something to the
effect that the not displayed 8 channels were grinding away in the
background doing something that contributed to the improved performance.
Maybe I should know better, with all the experts here. But I'm going to
see if I can find it again. I'll get back to you later.
Maybe, in the meantime, one of the other experts will enter the
discussion and divert some attention from me... :>)
Jack
--
Jack Erbes in Ellsworth, Maine, USA - jackerbes at adelphia dot net
(also receiving email at jacker at midmaine.com) |
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| Iwo Mergler |
| Posted: Thu Mar 08, 2007 1:44 pm |
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Jack Erbes wrote:
Quote: Dale DePriest wrote:
Jack Erbes wrote:
I have a GR-2313 and it is very fast and has good sensitivity too,
impressive for its small size. I also have the SiRF III in my Garmin
76Cx and I never cease to be amazed at the improved performance of the
SiRF III chip set over the earlier SiRF II. The SiRF III only
displays 12 channels but has 20. The other 8 channels are used in the
background.
Did you just invent the 8 channels in background stuff? There are no 8
channels in background. The SiRF III is capable of running the
equivalent of 20 channels on 1 dsp in that there is enough bandwidth but
if it is configured for 12 channels then that is all there is. There are
no more channels than the ones it is configured for.
Oh oh! Now I've run afoul of an expert.
I think I am paraphrasing something that I read here. Something to the
effect that the not displayed 8 channels were grinding away in the
background doing something that contributed to the improved performance.
Maybe I should know better, with all the experts here. But I'm going to
see if I can find it again. I'll get back to you later.
Maybe, in the meantime, one of the other experts will enter the
discussion and divert some attention from me... :>)
Jack
Don't worry, you're not alone.
A few years ago, GPS receivers used to have channels implemented
in hardware (correlators). There were between 1 and 12 such
channels, allowing to track between 1 and 12 satellites simultaneously.
Then some creative marketing soul discovered that a correlator
channel contains 3 correlators, so there was a short period
where receivers were sold with 36 channel labels.
The current generation of receivers have correlator hardware
which can be time-shared to process many parallel channels.
They also have a processor which can do efficient searches,
in some case with hardware acceleration for FFT and somesuch.
Thus some receivers were(/are?) sold with thousands of 'channels'
- a theoretical number computed from the initial acquisition
speed of the modern designs.
At the moment, the 'tracking' channels are being advertised.
As Dale pointed out, it just means that the receiver architecture
would be capable of simultaneously tracking as many satellites.
There is very rarely any point in tracking more than 8 satellites.
Add to that the augmentation satellites and 12 is plenty.
In other words, the number of channels is all smoke, mirrors and
marketing. Most other parameters of a GPS receiver are vastly more
important to the performance.
Kind regards,
Iwo |
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| Tobias Wendorff |
| Posted: Thu Mar 08, 2007 9:26 pm |
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Iwo Mergler wrote:
Quote: In other words, the number of channels is all smoke, mirrors and
marketing. Most other parameters of a GPS receiver are vastly more
important to the performance.
So which one would you suggest me?  |
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| Iwo Mergler |
| Posted: Mon Mar 12, 2007 8:59 am |
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Tobias Wendorff wrote:
Quote: Iwo Mergler wrote:
In other words, the number of channels is all smoke, mirrors and
marketing. Most other parameters of a GPS receiver are vastly more
important to the performance.
So which one would you suggest me?
The one which has a really good view of the sky. ;-)
It's the single most important factor for accuracy
and performance.
But if you want to compare receivers, look at the
sensitivity figures. They will help with the sky view.
In most cases, the exact receiver does not matter as
much as the rest of the system. You know, things like
size, battery life, screen readability, The Right
Color, navigation, whatever.
Kind regards,
Iwo |
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| karel |
| Posted: Mon Mar 12, 2007 3:08 pm |
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"Tobias Wendorff" <tobwenSPAM@gmx.de> wrote in message
news:esf7u5$u6k$1@online.de...
Quote: Hi there,
can anybody please recommend me a GPS-receiver for Bluetooth, USB
or the serial-port?
There are hundrets of different devices on the market. The chipsets
are: SiRF III, Sony, Atmel and MTK
I've read that SiRF gives the best results right now, but MTK seems
to have a high sensitivity and 32 channels for tracking satellites!
Is there any device under $100, which you could recommend me?
Lieber Tobias,
I enjoy good results with a HiCom 204,
basing on Sirf III technology,
(one link among many at
http://sklep.icom.eu/?act=prod_info&cat=22248&id=18751 )
bought it for some 60 euro's ohne MWs but that's distribution price
Karlchen aus Belgien |
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