Long distance bluetooth IS possible, yet some help

Hi there,

Recently I modded an Arduino BT by installing a U.FL-connector in order to be able to plug in an external 5dBi antenna instead of the internal one. However, I'm a bit sceptical if the range has become better. Is it useful to try a 9 dBi antenna or should I put an amplifier in the schema? And if the latter is true; where is to the most saneful to place the amplifier without frying my board?

Thanks in advance!

Modifying a blue tooth device like this is not recommended. It is not illegal to modify the device but it normally is illegal to use a modified device. This is for several reasons. First of all the resultant device is not "type approved", second it might exceed the maximum permissible ERP (Effective radiated power) for the band you are operating in. If you are in the UK or US then this is defiantly forbidden. Other countries you will have to check.

should I put an amplifier in the schema

The problem here is that you can have a receiver amplifier or a transmitter amplifier or both. You have yo then have either separate antenna for transmit and receive or some way of switching the amplifiers over or out.

BlueGiga just introduced the WT41. In the press release the range is specified at 1000Meters and the power at +20dBm. The module is around $35.

(* jcl *)

www: http://www.wiblocks.com twitter: http://twitter.com/wiblocks blog: http://luciani.org

Thanks a bunch! I also found a WiFi-antenna with an 'internal', so no headache concerning wiring up up a brand new module. Coming to think of it, an Arduino + Wt41 is actually cheaper than an Arduino BT.

Edit: But also more difficult to solder, aargtggh! >:(

I have not looked at the package for the WT41. The WT12 is easy to solder. with a decent iron. I have a BT board prototyped that uses the WT12. It plugs into the UART connector on the side of my NB1 (see http://wiblocks.luciani.org/NB1/NB1-index.html )

Unfortunately I haven't had a chance to debug the software. It pairs with my Android and the Android displays the name of the device but it doesn't connect :(

(* jcl *)

www: http://www.wiblocks.com twitter: http://twitter.com/wiblocks blog: http://luciani.org