An Interesting GPS unit

[Blue Sky]

I was thinking about how the update rate for most GPS's is a serious bottle-neck and how it would be nice to have a higher frequency update that could
be programed to supply only the data you needed.
Then I found this! It's mainly intended for hiding in your spouses' car so you
can see what they're up to. It has data logging, blue tooth, USB, an electronic compass, (yes, I know you would need to work around the 2 axis limitation) and can be programmed to upate at 4HZ!
It is also small, light, cheap and rugged.
I don't know if the 4HZ is for satellite data or only the compass, or if it is available at that speed in real time. The external speed seems to be 9600 bps while the internal speed to the data logger is faster.
Perhaps someone amongst us could hack it.
http://www.buygpsnow.com/wintec-wbt-100-4-in-1-gps-receiver-bluetooth-and-usb-gps-data-logger-for-offline-vehicle-tracking-with-google-earth-compass-free-arkon-vent-mount-609.html

-Dave

[JeffElecRC]

There have been small 4hz GPSmodules around for a couple years now. Check out http://www.u-blox.com/products/a4products.html. These are the modules used for the Paparazzi Autopilot.

[Blue Sky]

Thanks Jeff.

I had seen the U-blox modules before but had forgotten where.
That's what got me Googling for a 4HZ GPS update rate.
Is anyone familiar with the u-Nav chipsets and the iTrax 3rd generation engine?

-Dave

[TheBobby]

U-Blox has very good GPS modules, and new one are comming in 2007. There will be very interestening for our UAV projects.
In my team, we are dealing with an u-blox LEA-4P for one year now, and it's a very good GPS module. Not so hard to use. Documentations are very usefull especialy for the microstrip between the GPS and the antena support.

4Hz is now the only GPS modules to buy, 1Hz is too slow !

So yes, U-Blox is, for me, the best in GPS modules !

++,
Bob

[typicalaimster]

Ok here's my question. This does look like a data logger much like the one you can get from Spark Fun. I like the bluetooth download, however it does function on 2.4 ghz if I remember correctly. My concern would be that it would interfer with things like video downlinks. Can you actually turn off the bluetooth functionality if you don't plan on using it?

[Blue Sky]

According to the add: The stand-alone track recording function is independent from any host and can be operated with Bluetooth off. I'm not entirely sure that means it
isn't still transmitting but simply isn't linked to anything. I doubt seriously it would interfere with a downlink as it is much less powerful and not on the same channel.
The downlink may interfere with the Bluetooth although there is no need to have the
downlink on at the same time.

-Dave

[Blue Sky]

4Hz is now the only GPS modules to buy, 1Hz is too slow !

So yes, U-Blox is, for me, the best in GPS modules !

++,
Bob

Ah yes, things are only getting better!

-Dave

[typicalaimster]

According to the add: The stand-alone track recording function is independent from any host and can be operated with Bluetooth off. I'm not entirely sure that means it isn't still transmitting but simply isn't linked to anything.

Hmm interesting. I know I picked up a cheap bluetooth GPS based off the SiRF II chipset. I use it in my car along with iGuidence for navigation. I noticed the bluetooth will shut itself down if it sits idle for awhile. I wonder if they mean the same thing here.

[Hueber]

Hi!

Ok,I'm a bit late with my answer, had to register me first...

We're using the u-blox gps module on a uav-project at my university. And yes, it's really one of the best modules I know, because:
- We could set the update-rate up to 7 Hz (not only 4 Hz as written in the datasheet)
- It's fully programmable
- It calculates the vertical-speed (vario) in realtime via the doppler-effect, and not via the difference of altitude per time. Thus, its resolution is 0.01 m/s (!)

Btw, we use the gps-position we get from the uav for moving our parabolic antennas towards it. Hopefully we get some increase in the range...

[Corbin_Dallas]

This just came out.. don't know if it interests you, but here's what I've gatered:
20 Channel EM-406 SiRF III Receiver with Antenna - The EM-406 GPS module from USGlobalSat based on the spectacular SiRF StarIII chipset. This complete module is built upon the same technology as the ET-301, but includes on-board voltage regulation, LED status indicator, battery backed RAM, and a built-in patch antenna! 6-pin interface cable included.
more info and a $55.00 price tag @ sparkfun

[typicalaimster]

Actually I have been eyeing the Sparkfun GPS modules. I like how a few of them have the connector for an external antenna. This would allow me to mount the module say in the fuse of the plane. I could then mount the antenna in the wing near the outer edge or perhaps on one of my tail booms. The last go around I mounted the GPS on the tail boom and ran the pigtail back inside. I'd like to keep most of my electronics gathered in one spot in order to keep things clean.

[Tom Harper]

Typical,

I'm using an EM-406. Very impressive unit. Don't think you need an external antenna. Mine functions fine just sitting on the workbench.

Tom

[LukeZ]

U-Blox has very good GPS modules, and new one are comming in 2007.Is there anything specifically about the 2007 model that we should be watching for?

Luke

[Blue Sky]

Here's the u-blox TIM-LA module for $58.00.
http://www.elitstore.com/products.php?c=2
It's not u-box's latest module but it does update at 4HZ.
Of course you'll still need a board to mount it on and an
antenna.

-Dave

[reedchristiansen]

When we first saw this unit, we thought it was a very attractive little setup. Integrated battery, 25 mm patch, tight package, good connector, etc.

So we bought a bunch to try them out.

The good news is they have very good sensitivity. Tracking sats indoors, 10,11 sats outdoors.

The bad news is that the heading and position estimate is designed for automotive use. It is very filtered (almost 2 seconds behind another GPS unit we tested it against). This makes it very dificult to use with a UAV.

We really wanted it to work, so we spent a few days trying lots of tricks (using position output to calculate heading, etc) In the end we decided to not use it (we have a few we will sell for cheap!)

I called an engineer who put the unit together. He said their was not much we could do. It does come with software to allow you to tweak a few things, but unfortunatly, unlike the u-blox, you cannot change the filtering on position or heading.

Reed



This just came out.. don't know if it interests you, but here's what I've gatered:
20 Channel EM-406 SiRF III Receiver with Antenna - The EM-406 GPS module from USGlobalSat based on the spectacular SiRF StarIII chipset. This complete module is built upon the same technology as the ET-301, but includes on-board voltage regulation, LED status indicator, battery backed RAM, and a built-in patch antenna! 6-pin interface cable included.
more info and a $55.00 price tag @ sparkfun

[docphi]

I have one and have found it has a considerable delay. I wanted to use it mostly for altitude and speed display. However, it just doesn't update quickly enough even with WAAS enabled.