MCP23S17 address decoding

Viewed 5 times

I am planning on using the MCP23S17 port expander for my use case but upon wiring them up , it would seem that the MCP23S17 which is the SPI version of the port expander has address pins which is weird. The SPI protocol does not need addresses but instead rely on the Chip Select pin. What is this for ?

  • Ah let me see. The address decoding pins A2, A1, A0, are for you to select one of up to 8 MCP23S17s (See Datasheet Section 3.3). If you have only one MCP23S17, then you can connect those three pins to ground (CANNOT leave them floating) and use 000 to select the MCP23017: imgur.com/gallery/NamPVPW. – tlfong01 3 mins ago    Edit

Categories: Uncategorized

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.

%d bloggers like this: