WT12 Custom Breakout Board: Take 1

WT12 Custom Breakout Board: Take 1
Update 6/24/2011: the WT12 breakout boards I designed are now available on InMojo here (full, $50) and here (UART only, $40) for cheaper than you can get WT12 breakout boards anywhere else as of the time of this update. You can also download my Bluegiga Eagle library here.

The next major missing piece of Keyglove functionality is wireless support. This involves a battery, charging circuit, and a Bluetooth device. I’ve been working on Bluetooth for a while now, and after the difficulty with Broadcom BCM2042-based modules, I had some very exciting preliminary success with Bluegiga’s WT12 module (as described in this recent post). My rat’s nest of a test hookup demonstrated to me that the WT12 is perfect for the Keyglove, so a breakout board became the next priority.
Read more

Bluegiga WT12 Bluetooth Module Connection

Bluegiga WT12 Bluetooth Module Connection
Update 4/18/2011: you can read about the custom WT12 breakout board I designed here. The short version is that the board was almost good enough, but I’ve got a revision ordered and that one should be perfect. It will be available to others shortly.
Update 6/24/2011: the WT12 breakout boards I designed are now available on InMojo here (full, $50) and here (UART only, $40) for cheaper than you can get WT12 breakout boards anywhere else as of the time of this update. You can also download my Bluegiga Eagle library here. You may also be interested in the follow-up blog post about this.

So, after all of my experiments with BCM2042-based Bluetooth modules and the uncertainty and sparse documentation surrounding them, I decided to give Bluegiga’s WT12 module a try. I have to say, the more I learn and experiment, the more I like it. This one single module supports pretty much every Bluetooth profile ever, easily hot-switchable via a simple command. Their customer support is excellent. Their documentation, firmware, schematics, and all other development resources are readily available for free. Their modules are available for purchase cheaply in small quantities (e.g. one at a time for $27 from SemiconductorStore.com). You can control the complete behavior of the module using their capable iWRAP firmware and well-documented commands sent over the UART interface. It’s perfect.
Read more

Interfacing with a BCM2042/BP20422 Bluetooth HID Module

Interfacing with a BCM2042/BP20422 Bluetooth HID Module
Update 4/6/2011: the design files for the breakout board shown below from Wayne and Layne has been made available here. Thanks, guys! (Remember this board is optimized for the BluePacket BP20422 module, and the pair button doesn’t work with other modules.)
Update 6/24/2011: one guy has been able to successfully integrate a BP20422 clone module into an existing full-size IBM Model M keyboard to convert it from wired to wireless. This included a lot of custom circuit design work and firmware replacement, which may be useful to you depending on your own interests. Check out his detailed documentation here.

The CE Compass WKB-1500 Bluetooth Keyboard I ordered arrived in the mail a while back, and I took to testing and dismantling it immediately.

Now, I decided to buy an actual device instead of just a Bluetooth module for two reasons: first, and most importantly, the only source I know of for the HID-profile module I was looking at has been out of stock for quite some time. There is currently no place I’ve been able to find, even internationally, where you can buy a single HID-enabled module. There are many places to buy SPP-enabled modules, and in many cases these can be adapted to providing keyboard and mouse support. All they require is a driver on the host device to translate the serial data into input control signals. However, my goal is to have the Keyglove be detected natively as an input device, so that no special driver is required. The HID Bluetooth profile specification is basically just a hardware Bluetooth wrapper around the standard HID profile used with USB keyboards and mice, as far as I know, which makes it perfect. The only problem is that nobody sells those modules by themselves, so I decided to try taking one out of another device.
Read more