The following implementation is only a proof-of-concept that a OV2640 (or any other similar camera) can be easily connected to a MCU even without the right hardware interface. Most F4 indeed does have the DCMI interface for interfacing with such cameras, it was used only because the F4discovery board was handy.

My spaghetti code is dedicated to the public domain and I really hope that nobody will ever use it. Some foreign parts use different licensing.

Full description including the hardware connections is available at http://qyx.krtko.org/projects/ov2640_stm32/

The repository now contains a DCMI-enabled version running on the F4Discovery board.