LibreTooth is a side project I developed during my various human-computer interaction device prototyping. In the past, I’ve been a fan of Sparkfun’s Bluetooth Mate Gold, a breakout board for the Roving Networ’s RN-41 Class 1 bluetooth module. It’s quite superior to other cheaper Bluetooth modules you may find in China through ebay.
Unfortunately, Sparkfun sells it at more than 60$ (which became 70€ on EU sellers) and they also don’t release its designs as open hardware. The RN-41 and RN-42 (same as RN-41 but Class 2) can both be bought from Mouser at about 20€ while cheap PCB are available from Dorkbot PDX as usual. So, I decided to design my own Bluetooth Mate inspired hardware: LibreTooth!
LibreTooth is a completely libre hardware project, released under CC-BY-SA 3.0. It has been designed using KiCAD, a Free/Libre/Open-Source Electronic Design Autonomation suite. You find all the schematics and designs for building your Libretooth in the links at the bottom of the page.
Libretooth can both be used with the RN-41 or RN-42. The first one is a Class 1 module which will offer longer distances but higher current consumption while the RN-42 is a Class 2 module offering smaller distances but it is also more energy efficient. The board design is fairly similar to Sparkfun Bluetooth Mate. I just also broke out the reset pin on the bluetooth module to allow programmable reset of bluetooth communication.
Below all the desings: