Quote Originally Posted by Demon View Post
This is great stuff. I use the MCP23016, but this new IC is much faster.

Can you explain how you came up with the 3us delay in the 3rd approach? I look at your comment and the SPI characteristics in the datasheet and don't know what to use exactly.

Robert
Hi Robert, Thanks for your comment.

Hi came up with 3 uS by trial and error. I tried 2 uS, but it wasn´t enough. The problem is not the MCP23S17, but the SSPUBUF register of the PIC. I think if you run the PIC faster, for instance @20Mhz, you can even reduce that time.