SENA Bluetooth serial adapter

[justDIY]

Has anyone worked with these particular bluetooth modules before? I was googling for a less expensive alternative to Sparkfun's $65 bluesmirf and ran across these little guys:

**broken link removed**

the one I'm looking at is the ESD-110, which is much smaller than spark's module, includes an sma extension cable, panel mount antenna holder and a dipole stub antenna, compared to Sparkfun's smirf which includes nothing. It also appears the Sena module is half the length of the smirf, while providing a more robust rs232 interface (RTS/CTS and DSR/DTR).

A few advantages I can see to the smirf - Sparkfun has included level shifting hardware on the module, making the IO lines 5v tolerant for a 3.3v device. They've also included some sort of hardware (shunt regulator perhaps?) making the power input flexible from 3v to 6v. Lastly, the Smirf claims to draw 25ma while the esd-110 claims 70mA.

 

[justDIY]

I took the plunge and picked up one of these sena modules. it is impressively small!

the module is about the size of an American quarter dollar, and comes with a easy to use 2x6 pin header on the back. the bluetooth chip and presumably some other circuitry are sealed behind some steel shielding. The device is 3v only, so it needs a little help talking to a 5v pic project.

I plugged mine into a bread board and powered it up with 2xAAA batteries. Right away I was able to detect the module and connect to it using the SPP profile. My initial connection was even at moderate range, as my lab is on the other side of the building and one story up from my office. I'm using a trendnet high power bt dongle on my desktop and the sena came with a miniature dipole stub antenna.

I was using my max232 breakout board to make the connection between module and desktop, but the max232 wasn't too happy working at 3v, so I was only able to test transmit, the receive portion wasn't working - presumably from lack of voltage. I've got some ST3232 on their way, which should let me get down to business.