I had the same idea to use the fingerprint scanner of the Framework laptop on a desktop and was happy to see there’s already some discussion around it. I also plan to eventually build a nice enclosure and custom PCB for it, but I decided to do some testing first.
So, I recently ordered a Framework fingerprint reader and a few FPC cables and a FPC connector breakout board from AliExpress. I finally found some time to test things today, and can report that after some initial hiccups, the fingerprint sensor works great on my desktop!
Firstly, the notched cables are definitely wider than the usual FPC cables you get. Means, the cable that came with the fingerprint reader kit doesn’t fit my breakout board, and the cables that I ordered have some wiggle room in the fingerprint reader module. Kyocera has a nice datasheet that shows a comparison between the two cable types. The notched cable has an extra 0.65 mm of width. Not ideal, but with some careful alignment, there’s enough contact.
The wiring information was extremely helpful, I only swapped the data lines at first - it seems that I needed to connect D+ on the USB-C breakout (that I still had) to D- on the fingerprint reader module (pin 3).
It was immediately recognized as a USB device after correctly wiring it, however my replacement module unfortunately didn’t have a compatible firmware (01000320 instead of the newer 01000334).
There’s been some discussion around this here:
I unsuccessfully tried various steps from the linked discussion post (fwupd on desktop, manual cab flash on desktop, manual cab flash with the module connected to my Framework 13 via USB, a Windows VM with the driver bundle on my Framework), but finally, the steps from the official update guide worked (fwupdmgr refresh --force && fwupdmgr update --force) on my Framework. It doesn’t even matter that two modules are connected at the same time (one built-in, one via USB).
Now, the next step is building a proper enclosure.