Analyzing The Microsoft Surface Touch Keyboard Cover

The Microsoft Surface is an awesome Tablet PC, but it has one problem: there is just one USB port on it. There is an additional port, though: a connector for the Surface Touch Keyboard connector. That’s what [Edward Shin] is looking into, with the long-term intention of creating an adapter that allows him to connect a Thinkpad keyboard to this proprietary connector. His initial work identified the connector as using Microsoft’s own HID over I2C protocol, which sends the standard USB HID protocol over an I2C connection. So far so good, but it seems to get a little odd after that, with a serial connection running at nearly 1 Mbps and sending 9 bits per transfer with 1 stop bit. Presumably this is because Microsoft had planned to release other devices that used this connector, but this hasn’t panned out so far.

Anybody want to help him out? He has posted some captured data from the connection for analysis, and is looking for assistance. We hope he manages to build his converter: a Microsoft Surface with a decent keyboard and an open USB port would be a great portable setup. Bonus: for those teardown fans among you, he has done a great teardown of a Touch Cover keyboard that reveals some interesting stuff, including a lot of well-labelled test points.

Via [Reddit]