PB1 and PB11 - Input
PB0 and PC13 - Output
lost the pinout, meh
anyway, there should be a clock input (1Mhz) and a start-frame-input (trigger)
accordingly the bluepill will generate a waveform which represents the ccd. It contains a wave with constant phase shift, which emulates a digipan movement. Also there is another output, i guess it is a frame done output. I will figure that out.