After organizing the 2012 U23 at the C4, I again was part of the organizers in 2013.
We again did a project based on the STM32 F4 Discovery. In 2012 we abstracted all the details on how to use the hardware away using a library. This time we wanted to teach the participants how use the microcontroller and its peripherals.
We wrote a few examples and a small amount of bootstrapping code this time: https://github.com/cccc/U23_2013_examples
All the slides are available in German language in the public C4 wiki: https://wiki.koeln.ccc.de/index.php?title=U23_2013