I try to learn to use ov7670 ,but something went wrong with the llibrary

I found This How to Use OV7670 Camera Module with Arduino​ Uno after I realised that all the libraries I could find in the Arduino-sphere worked ONLY on SAMD processors.

I haven't got it working YET, my hands are too shaky & eyes wont focus fine enough to make the adaptor to hold the line voltage down to 3.3v.
mick