After my original post about the WT12 breakout board I was working on a while back, I thought I should really follow that up with some info on what’s happened with that adventure. In short, it’s been a great success! The PCB revisions that I made proved to work very well, and I now have two great boards available for purchase through InMojo, as well as an Eagle library if you want to make your own.
The first is a full board that breaks out every pin of the module, and fits on a standard solderless breadboard with enough room to use the pins. It also has a separate UART header that is pin-compatible with SparkFun’s BlueSMiRF boards. The second is basically the same hardware, only it’s cut down to only the size and connections necessary for UART access.
As far as I am aware, this is the absolute cheapest way to get an assembled breakout board for this module, and I would argue that this is the best Bluetooth module out there for simple microcontroller access due to the very capable iWRAP firmware that supports multiple profiles, including the elusive HID profile.
As I mentioned before, I designed the PCBs in Eagle, and while doing so, I created a Bluegiga Eagle library with a full range of Bluegiga’s Bluetooth modules (including the BLE112 Bluetooth Low Energy module). All are designed strictly to the datasheet specifications, but I have only actually used the WT12 part in my designs so far. Feel free to use the parts in your own designs, and if you do, I’d love to hear about them!
Most of Bluegiga’s modules come in a couple of different variants, usually with and without an on-chip antenna. The Eagle library includes parts for both variants in the cases of modules that include them. Additionally, each variant of every module has a normal schematic part and a “visual” schematic part. For the normal parts, the pins are arranged into logical groups based on their function, as is often the technique used in schematics. The “visual” parts have the pins arranged exactly as they are placed physically on the module, which makes breakout board designs simpler. It is up to you which version you want to use.
If you need a powerful Bluetooth module for your MCU project, I highly recommend this one. It’s working great for me so far with the Keyglove, and Bluegiga’s documentation and support are excellent.