I’ve decided to stop working on the ThinkPad keyboard adapter with Bluetooth support. It’s taking too much time and the work is repetitive. I’ll probably just add UART to my USB board, add in a LiPo charger and modify the firmware a bit. It’s possibly not going to be energy efficient compared to using interrupts on the keyboard inputs and the TrackPoint clock line.
Also, prices for MSP430 parts are jacking up. It’s simply not economical to use them anymore. I’ll switch to ARM Cortex-M0+, like Freescale KL2x series.
Thus, here’s the schematic to the ThinkClamp PCB v0.8. I hope it helps you with your future endeavor with building a keyboard & TrackPoint adapter.
Update: It’s been 2 years since the project completed, may as well share the schematics. Sad news though, I can only find v0.6.2 on hard disk: ThinkClamp v0.6.2.
As for folks who would want to build a case, I’ve made a 3D model of the ThinkPad T60 keyboard: Grabcad.
Finally got some spare time yesterday to solder the new PCB revision and it works well, some better than anticipated. I’ve found one or two PCB errors. Nothing major though, it’s all working well enough.
I decided not to solder on the reset buttons as a slide between the ON and OFF positions of the slide switch would effectively reset the entire board.
Soldered board with MSP430F5502 and HM-10
Now it’s time for some programming. With a USB-enabled microcontroller, this board would eventually support both USB and Bluetooth functionality, preferably with the same firmware flashed. I’ve decided to use the HM-10 with my custom firmware instead of using a RN42-HID module so I can further improve the firmware.
Update: There might be a minor problem with the LiPo charger in which the battery voltage may jitter when a battery is not connected. This caused a bit of a random enumeration/disconnection problem. However, if a battery is connected to the battery output pins, the board seems to work fine. The USB microcontroller enumerates with no problems at all. For now, I’ve soldered on a single-cell battery pack so that I may get on to write the firmware.