it's been week since I stuck on this problem, I have a board like this , SPI3 MOSI PB5 is connected to ic 74HC594s to drive LEDs, and MISO PB4 is connected to 74AC165D to get the four SW (buttons) for input purpose, and the PB3 for clock on both ICs....

All I need is a simple example CAN normal mode, I been searching around but found nothing. It just for educational purpose. Appreciate for any help