Bluetooth GPS Haicom HI-406BT/Asus Netbook

Found an interesting problem with the following symptoms:

The Bluetooth GPS would show a solid blue light, MS Streets & Trips would not recognize the input, and the GPS would be disconnected after a while.

Power on and off resets of the BT GPS and Laptop does nothing - problem comes right back.

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Solution:

BT signal is too strong and somehow crashing either the Asus BT module or the GPS.

Move the BT module at least 3 ft away from the Netbook.

Everything works fine.

Are you sure that the problem isn't related to the placement of the GPS with relation to a solid satellite view. A better test would be to move the netbook close to the GPS while the GPS is already in a location conducive to receiving a good signal.

Or this could be just as you suspect and similar to the USB GPS problem with netbooks. The netbook rf shielding is poor and overpowers the GPS satellite signals rendering the GPS receiver inoperative (not related to Bluetooth though).

Terry

I tried the identical setup (BT GPS virtually next to BT Receiving module on Netbook) in multiple locations, and got the identical problem.

Move the GPS 3 ft away, restarted, and problem went away.

It can be that ASUS, a known chintzy maker of cheap stuff, used a real cheap module.

I will try the test you suggested when I am on the road --- the trouble is indicated by a "solid" blue LED on the GPS that normally blinks when the BT link is fine.

I'm not familiar with that GPS but the blinking light could indicate a satellite lock rather than a BT connection if there is only one light. Regardless, the advantage of BT is you can place the GPS at a good signal location away from where the laptop is most visible to you.

I don't think this problem is limited to ASUS or is a function of chintzy design. The netbooks are stuffing a lot of functionality in a small package and may not be as well shielded. The USB GPS problem shows up on full size laptops too.

Terry

OK, here is the latest:

I am getting intermittent failure (i.e. it would just crash, disconnect, etc. and S&T reports no GPS even if it says COM05 is there).

I don't know what issue causes it to just intermittently fail...

Am going back to the USB GPS for now.

When I was testing mounting a Navibe 720 on my ASUS EEE laptop, I found that the GPS signal was reduced in half when I was in a glass spa with a clear view. This resulted in poor reception. When I brought the GPS mouse near the laptop display the signal was reduced to bearly readable. Taking the laptop out side and moving the Navibe away from the laptop restored full satellite strength. I now use the ASUS EEE with the same USB mouse mounted away from the laptop with out problems. See Oct 2008 at http://thomasofneedham.com/laptopGPS/Test_Notes.html

That explains it.. the ASUS is leaking radiation that conflicts with GPS signal...

... and I actually think that most laptops, and especially the smaller netbooks, do emit RF signals that interfere with GPS reception, if the GPS receiver is in very close proximity. It's not a problem as long as you use at least a foot long USB cable between your USB GPS receiver and the computer, or if you use a Bluetooth GPS receiver, so the units are not too too close.

The other issue in this case (the glassed-in spa) is the glass. It's probably Low-E glass, which has a metallic coating to minimize solar heat transfer. Modern glass in many buildings and many vehicles can reduce the GPS signal quite a bit.

...ken...