Add a bluetooth adapter to your GPS device

I needed a way to hear my cheap a$$ GPS under the helmet on my motorcycle and didn't wanna fork over 2x the price for a "motorcycle ready" GPS device so I made it myself.
This may be interesting to bikers a well!

You can also find it here:

GPS + bluetooth

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Step 1: Open it...

When you CAREFULLY open your new TomTom One you'll notice that there is a battery and a speaker on the back and all the electronics on the front side.

roonie3 says: Jan 12, 2011. 4:53 PM

i got a garmin 265wt gps for Christmas and want to connect it to my motorcycle helmet intercom (starcom advance) problem is i have no audio out plug on the gps ?? couldnt i do this same thing on my gps and then get a male to male cord so i can hear the voice from the gps ooooooorr should i try and make the intercom a bluetooth like the gps ?? the intercom has audio input plug already anybody please hep me ooooo hep me please

taffie79 says: Aug 10, 2010. 9:42 AM

IF the gps has an audio out socket included is there anything i can buy to make it have bluetooth

beannie says: Jul 11, 2010. 3:47 AM

But how can I simply make bluetooth as a switching device??

tofu1 says: Sep 13, 2009. 3:34 PM

I've been riding around and just hating always having peek down at the screen (since i cant hear anything) very simple, GREAT IDEA!

Dodgy says: May 14, 2008. 11:05 AM

So, doesn't this model of tomtom include an audio out socket? Couldn't you just buy a model that has one ? I bought 4 in Dec. 2007, and all had headphone sockets. Did you show how to wire the switch connection on the socket, so, when you don't have anything plugged in, then the sound is routed to the internal speaker ? Or is it so that you will never hear the internal speaker again ? Why not dismantle the Bluetooth device, and fit it inside the case ? Surely it can be made to fit. One of my GPS units has an FM radio transmitter. So I'd need to have a tiny tiny FM radio earpiece.

Sudija (author) in reply to DodgyMay 14, 2008. 11:24 AM

Weeeell, if it did have an audio out why do you think I would wanna make my own? No, the model I purchased for $300 in 2006 did not have that. Nothing is routed and there are no switches in my mod, signal is just doubled and you can still hear the speaker. That is if you're not flying down the highway on a motorcycle. If you can make a mod with the switch I would welcome that. Why not dismantle the Bluetooth device? Surely it can be made to fit??? What makes you claim such thing? It would be nice of course, but two things: 1. It surely CAN NOT fit 2. Even if it fit, the converter from the GPS device power to Bluetooth power would not. I did not understand the last thing with FM ?!?

azntrooper93 in reply to SudijaSep 4, 2009. 7:30 PM

FM is a the raido junk

toenailridge says: Jul 21, 2009. 10:25 PM

Excellent project. Just did this with my Navman S35 GPS. Worked perfectly. Many thanks for the idea. Phil in Adelaide, Sth Australia

marinojr says: Apr 18, 2009. 4:57 AM

Where can I to buy this one on-line and how much ?

Sudija (author) in reply to marinojrApr 18, 2009. 8:00 AM

Try Cardo website or e-bay. Cheers,

mikerealest1 says: Mar 9, 2009. 11:31 AM

I'm a novice....how do I get my Tom Tom to come apart? Are there any tools I need to open it

Wildrat says: Mar 5, 2009. 8:51 AM

Great Idea! It's funny all the "why not do it this way or that " comments you get from people that partially read the instructable or they just think they can do it better, when in fact they can't even sharpen a pencil to a point. I like all the Instructables whether they are great or good, at least they are thinking and doing. That old saying 'money talks and BS walks" could be changed to "Instructables talk and BS walks" Great job to all that have Instructables and keep it up, I enjoy seeing them all, and sometimes building upon the original idea!

Yerboogieman says: May 29, 2008. 4:53 PM

PEOPLE, STOP USING PAINT TO CIRCLE STUFF! USE THE YELLOW BOXES!

sparky in reply to YerboogiemanFeb 25, 2009. 9:14 PM

haha! i feel your pain Nice gps mod!

strider_mt2k says: May 5, 2008. 4:45 AM

This is interesting because: A: I recently modified my Mio C230 GPS to have an external speaker jack and B: I own one of these BT modules. The only problem is that I don't think they play nice with Motorola BT headsets as you need to enter a security code or something. Either way it's an awesome idea and I'll have to drag that stuff out to play around with it now! Thanks! :D

erikwillke in reply to strider_mt2kMay 24, 2008. 11:14 PM

I have one I'm not using anymore. let me know.

pbwingman11 in reply to strider_mt2kMay 9, 2008. 7:17 PM

Most often, if a security code isn't chosen by the user, it's: 0000 (four zeros). It's been the case with any of the bluetooth headsets I've owned.

karmagirl says: May 10, 2008. 7:53 AM

This is awesome. I don't have a GPS unit but I can see this being super useful for hacking anything with a speaker. Thanks!

halibaitor says: May 8, 2008. 3:39 PM

Can you provide a Radio Shack part number for the device in step 2?

Sudija (author) in reply to halibaitorMay 9, 2008. 7:36 AM

That is a Cardo Universal BTA II - bluetooth adapter for non-bluetooth cell phones. I don't think radio shack carries it anymore, I bought that one for it's size
(and it was on clearance!) but you can really use any adapter for non BT phones.
They all have a 2.5 mm plug (2.5mm receptacle is often found on cell phones) so once you have your GPS drilled and the receptacle in place you can plug any adapter.

BTW I still have two additional plug receptacles left if you need it. Manufacturers of parts like this usually sell them in gazillions so if you write to them and ask for a sample they will send you few free of charge. :)

strider_mt2k says: May 5, 2008. 5:12 AM

Which wires exactly are you connecting to the jack from that that Nokia adapter? There are three wires coming off of the jack. I ask this because the external speaker jack I modded onto my Mio GPS is a 1/8 inch stereo jack. I'd like to simply replace the plug on the BT adapter if I can and this will save me a lot of steps beeping stuff out.

Sudija (author) in reply to strider_mt2kMay 5, 2008. 10:52 AM

Hi there Glad you liked my instructable, I don't quite remember where these two wires connect of top of my head by I do remember t took me a minute to figure that out by just trial and error. In any case you will not be able to get stereo sound out of this since there are just two wires going to one speaker on the GPS that you are hijacking. Good luck!

strider_mt2k in reply to strider_mt2kMay 5, 2008. 8:39 AM

Never mind. I need a BT headset that'll work with this thing first, but I'll be able to figure this out when I do. Still a great idea!