PDA

View Full Version : DIY Bluetooth for less than $100



grusomhat
31st January 2010, 10:29
Well at this stage it's about $75 worth :) Anyway, here's a quick guide to setting up a cheap bluetooth system on your bike for music/radar detector/possibly cellphone. This guide is pretty vague and I wrote it in a hurry so it's shockingly written. It should work with most helmets but check out yours first.

First thing you need to buy is a bluetooth transmitter and bluetooth headset both available from DealExtreme:
Transmitter: http://www.dealextreme.com/details.dx/sku.8889
Headset: http://www.dealextreme.com/details.dx/sku.29546

Postage from dealextreme is free but expect for it to take upwards of 3 weeks.

The transmitter is very compact and connects to any device with a 3.5mm heaphone jack. Using a double plug you can listen to music while using a radar detector (my plan).
The headset is also nice and compact but not enough so you have to remove the plastic casing.

A warning before pulling it apart though. The speakers inside have a VERY thin plastic membrane(?) and it is crucial that you don't touch it with anything otherwise it dents and makes the sound horrible (There is a fix though, just). The other warning is more obvious. The wires inside these are TINY and will snap very easily. The less handling/bending/flexing the better so be careful when moving things.

The headsets unscrew and clip apart quite easily although the back can be difficult to unplug. Unscrew the circuit boards and removing it all from the casing to be left with this:
193291

Next we need to remove the steel balls that are on the cord between the headset. The cord unplugs from both earpieces, use something small and flat to unplug it. I then ground the last ball off and the other just popped off.
193295

Now's a good time to protect those speakers so cover them back up with the plastic piece that unsrewed off the front of them and tape it on with a small strip of duct tape (don't block any holes on the front) and then put the foam back over.

193304

Now we need to add a switch for turning the headset on/off. The switch is just a simple momentary switch. You can find one at DSE or use one from an old computer. This needs to be soldered on to the sides of the current switch. Work out how long the wire needs to be first!

193304
^^Bottom left - blue and white wires^^

Now with the cord you unplugged before, place it behind your liner and bring each end out near where you want your earpieces. Plugin both circuit boards and position them behind the liner and position the speaker behind where your ear would be. Double sided tape works well for holding things in place. Run your switch to where you want it and you are pretty much done.
193290 193293
http://img402.imageshack.us/img402/1580/p1310143.jpg
http://img194.imageshack.us/img194/5425/p1310144.jpg
http://img402.imageshack.us/img402/1283/p1310150.jpg

The transmitter can run on batteries so you can plug it into and ipod/mp3 player in your pocket.
193302

The headset needs some further refinement, you may have noticed a lack of charging plug. I'm going to extend it down to near the switch once I find a plug. There are also other features that have been missed such as the microphone and volume buttons. Full volume works well, everything has its own controls anyway. I may bring the mic down if I ever get a phone with bluetooth (the power switch works for answering the phone and it mutes everything else) however you would probably still have to pull over to use it.
For the transmitter I plan on mounting it under the seat with a 5v regulator and a relay. Will need to bring the switch on it up near the handlebars probably.

As at this stage I haven't tested if it's loud enough as it's currently raining. Thought I would write this while I wait.

Enjoy. Let me know if anyone else attempts this. I would suggest buying a bluetooth receiver adapter instead of the headset though. That would allow you to use any headphones and you can mount the receiver at the base of your helmet/in your jacket.

CookMySock
31st January 2010, 10:46
Thats a cheap afternoons' entertainment. Good fun!

Steve

TimeOut
31st January 2010, 12:50
Hi
I hope it all works

Would the transmitter pair with a bluetooth Scala Rider?

grusomhat
31st January 2010, 13:42
Hi
I hope it all works

Would the transmitter pair with a bluetooth Scala Rider?

It looks as though it may but you won't get stereo as the Scala doesn't support the A2DP profile needed. I can't guarantee that it will though as I don't know an awful lot about bluetooth.

grusomhat
11th February 2010, 15:19
Been for a couple of tests now. Volume is good, however bass is terrible unsurprisingly. So not too bad for music.

The bad news though is they are useless with something that only outputs audio intermittently as the transmitter has auto-off! IE useless with a radar detector. So back to headphones :/

Jonno.
12th February 2010, 17:04
How do you connect that transmitter to two things?

grusomhat
12th February 2010, 18:49
How do you connect that transmitter to two things?

A dual 3.5mm plug into a single. Something like this: http://www.maplin.co.uk/Module.aspx?ModuleNo=1214

I haven't tried it but I don't see why it wouldn't work.

Jonno.
12th February 2010, 21:52
Wouldn't you want it the other way a round; one jack and two prongs?
Not tryna bring ya down, keen to make one.

grusomhat
12th February 2010, 22:13
Wouldn't you want it the other way a round; one jack and two prongs?
Not tryna bring ya down, keen to make one.

um, well I guess that would work as well but would be akward. You'd need two 3.5mm plugs female-male and one male-male plus the plug would be hanging in the middle. Whereas with the two into one you run a 3.5mm plug from the headphone output of each device into the plug and then you can plug them both into the transmitter. Only needing two 3.5mm male-male.
Here's a crude drawing
196084

Anyway I'm back to the drawing board thanks to the aforementioned auto-off feature. Until I can sort that I'm back to headphones.

I would definitely recommend a different headset choice. The transmitter is nice though and a good buy. Haven't opened it up yet though so unsure of its modability.

I'd like to build something from scratch but that's a way off :(

Okey Dokey
13th February 2010, 08:01
What you have done is very interesting. Thanks for sharing your expertise with the rest of us. Pity about the auto-off feature. Let us know if you can figure a way to work around it.

grusomhat
13th February 2010, 08:47
What you have done is very interesting. Thanks for sharing your expertise with the rest of us. Pity about the auto-off feature. Let us know if you can figure a way to work around it.

Definitely. Broke one of the speaker wires off this morning taking them out of my helmet so I've got an excuse now to use different speakers. Fingers crossed I can disable or bypass the autooff.

banditrider
13th February 2010, 10:33
That's some cool work - well above my level. Just a quick question: I have a Zumo with bluetooth but I understand it is only a mono signal through the bluetooth, would those headphones work ok? I don't care that it's not stereo but would I get sound in both speakers?

grusomhat
13th February 2010, 19:00
That's some cool work - well above my level. Just a quick question: I have a Zumo with bluetooth but I understand it is only a mono signal through the bluetooth, would those headphones work ok? I don't care that it's not stereo but would I get sound in both speakers?

Um good question, I have a feeling it will just be on the left channel. I'm not sure how bluetooth would handle the mono-stereo conversion and I've got nothing available to test it unfourtunately.

R-Soul
26th February 2010, 12:33
Is ther some way to connect two way walkie talkies to a bluetooth headset? I just wanna talk with my buddies - thats all.

Could you plug the transceiver into a two way radiio, and then mount the two way radio on the handlebars?


If it would only be useful for phones, I believe that some phones can be used as walkie talkies with their bluetooth? Do yo know if tthis is true?

Frankly the cost of these intercom radios is ridiculous. Its an earpiece that you can buy on a 2 dollar shop, and a walkie talkie that is available for $50. so where do they get off charging $450? Freaking greedy Cnuts.

I am going to get a Chinese manufacturer to whip one up, dammit.