Friday, January 1, 2010

Maemo Minute #2: N900 & Bluetooth DUN

Philip Langdale's bluetooth dial-up networking daemon (BT-DUN) for the Nokia N900 is a real godsend. Now I can tether my N800 and my laptop to my N900.

OK... What does that mean for an average N900 user?

I setup a BT-DUN connection to the N900 on my Win XP Pro laptop for those times at the airport when I need more screen real estate than the N900 affords. For a single user, this is a great way to share an internet connection.

I'm planning on setting up my N800 as an in-car computer with OS2008 maps, Canola and Carman as the 3 anticipated usage scenarios.

Why not the N900 for in-car use? Simple. Screen Size! At arms length, the N800's screen makes manipulating buttons much more friendly.

In addition, on long trips, I can pass of my well used N800 to my passenger to surf while the shiny N900 sits in its cradle or jacket pocket (no selfishness there).

Interestingly, while a device is connected via BT-DUN, the N900 is able to maintain its own internet connection. Either the same connection as the tethered device, or a different one (wi-fi, for example). The screenshots below show that the N900 is connected to wi-fi while the N800 is tethered to it using the cellular data connection.


Figure 1: N900 IP while N800 is tethered (N900 on wi-fi and N800 on cellular data)


Figure 2: N800 IP while N800 is tethered (N900 on wi-fi and N800 on cellular data)

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Marius Gedminas said...

Can you please confirm that the N900 is able to use the 3G connection at the same time while a different device, tethered over Bluetooth DUN, is also using it?

Or did I misunderstand your post?

EIPI said...


Sorry if the post was not clear. You can connect the N900 to the 3G connection, and also have a device tethered to the N900, using the same connetion.

What I was trying to show via the screenshots was that the N900 could be using a different connection for itself (the tethered device still can only use the 3G connection)

James said...

This question comes up over and over... if you are a former 800 or 810 user, you may be disappointed.

The N900 does not tether outgoing TO another 3g cell phone device as easily as the 770 800 or 810.
(I and many others, tether 800/810 to our 3g cell phones for internet access...expected this to work on the 900 like normal....NOPE!)

Since the 900 had a phone built in, it seems the expectation was that we customers would want to connect our laptop to the 900 for internet access...not the other way around.

it can be done but it not easy, and requires additional skills and time to accomplish.
I am doing it with the help of some posts by "matan" on
Reflash alternate kernel (kernel-power)
Load Matan's app for BT DUN CLIENT...note, "client"
Set up 2 shell scripts to connect to cell phone and log in
On the bright side, you can use the built in phone 3g (if you have a service with tmobile) and run a hotspot app to provide an AP from your device..similar to a mifi.

(it should work also with the 3g tether connected, however I have not yet tried it)