Port alias in Port Expanders (MCP23S17)

[ecoli-557]

Thanks, I will give that a try.
Now if I could write both bytes at the same SPI communication, that would be an even bigger win!

[tumbleweed]

If you have the MCP23S17 IOCON register set to it's default setting of $00 that sets the chip to 16-bit mode (BANK=0) with auto address increment enabled (SEQOP=0).

In that mode you can send register address byte = $14 (OLATA) and then write the two data bytes and they'll go to OLATA and OLATB.

[ecoli-557]

That is exactly what I was looking for!
I thought I had done this before but could have been mistaken.
Will try later this evening.
Thanks!
-Steve