Very cool writeup, thanks for digging into all those data sheets and sharing it with us! I feel like the hands-on electronics stuff has always been a little bit inaccessible to me, but posts like these always make me a little more excited to start doing little projects myself. So thanks for posting.
Here is to hoping someone will do something similar for DRM'ed BOSCH ebike motors.
Please not. Bike thieves are already annoying as they are (a ring in the rural city I live in managed to steal over 400 k€ worth of bikes in a matter of months, in my case they only stole the control unit), and so are people modding their bikes to run (way) faster than the legal limit, leading to more and more calls for them being banned off of normal bike tracks.
[1] https://www.idowa.de/regionen/landshut/landkreis-landshut/se...
We desperately need some large ass legal fund that takes the GPL violators to court.
The GPL also does not state that the source code should be easy to find. In the early days, one had to write a letter, send it by mail, in hopes of getting a tape or CD-ROM with the source code. For which you then had to pay as well.