Bluetooth prototype

January 11, 2012 7:46 AM

What is the easiset way to prototype a small bluetooth device.

I'd like to prototype a small bluetooth device the size of a keychain. What is the easiest way to do this? Are there already integrated, arduino or otherwise, boards small enough?

If looking for already integrated solutions is the wrong direction, and that I should be able to wire a few cheap simple parts onto a breadboard to get something running, please let me know. I don't know enough about EE to ask more intelligent questions.

posted by Ad hominem to technology (7 answers total)

You need to tell us a little more about the device. What part of BT does it use? Is it for audio, is it a serial port, or is it some custom data you want to send?

Usually, in these situations you want to buy a "development kit" which has the BT radio and a general purpose processor, as well as inputs and outputs, on the same board. Then you program it to do what you want, prove the concept, and then work on miniaturization. You may also be able to start with an Arduino and a BT board.

Alternately, if the functionality of the device is effectively the same as some commercial device, but is operating in a different context, or is in a different form factor, another approach is to buy a commercial BT device, like a headset, and modify it to fit the new form.
posted by fake at 7:50 AM on January 11, 2012

Well I guess there isn't much danger of someone stealing my idea and rushing to market.

I would like to build a Bluetooth keychain that vibrates when your phone has an incoming call or SMS. Even better if it had a small LCD display to show the number or text as it comes in.
posted by Ad hominem at 8:01 AM on January 11, 2012

Here's a Bluetooth-enabled PIC development kit thingy with USB that might be usable, but as fake says, it would help to know more about what you're trying to achieve.
posted by le morte de bea arthur at 8:02 AM on January 11, 2012

You should do this because it is a fun project and a great way to learn about electronics but you should also know that commercial versions already exist.
posted by ChrisHartley at 9:24 AM on January 11, 2012

Sparkfun has a ton of different bluetooth modules several of which should work. Paired with a small rechargeable Lithium battery and an Arduino Mini Pro, you should be able to get a prototype working that's about the size of a pack of gum. Though I'd probably make the first prototype at larger scale. When things get small, making changes gets difficult.

As ChrisHartley mentioned, there are similar commercial products out there that do exactly this, but it still sounds like a fun project!
posted by Ookseer at 5:37 PM on January 11, 2012

Thanks for the electorincs links so far and thanks for the product links, existing products prove it is a viable market!
posted by Ad hominem at 7:26 PM on January 11, 2012

Seconding fake - if you don't know much about this stuff, you have some learning to do. Find a cheap headset and start cutting wires. If you go with an Arduino and bluetooth shield, you're looking at quite a large device already. Prototype on this, then use a nano for the final version.

If you play with an off-the-shelf device, it should be fairly easy to simply intercept the wires which control the ringtone on the headset and use that as a basis for everything else.

There are many different bluetooth profiles and different ways of driving LCDs; it won't be easy to make all this as a small device as a hobbyist.

There are bluetooth serial interfaces available on eBay for around $10 (no names to hand, sorry) - but they may not be responding to the correct profiles for handling calls.
posted by davemee at 3:44 AM on January 12, 2012