MCP23017 BoB with DIN rail mounting and proper wire to board connectors and indicator LEDs.

Features

Reliable spring cage wire to board connectors
Pluggable power and I2C connector
Indicator LEDs to display IO state for input or output
Selectable address to enable connecting 8 devices to same bus
Functions the same as MCP23017
Possibility for pull up resistors (recommended to pull up at host)
Operation even down to 1.8 V (LED operation down to 2.5 V)

Supplies

MCP23017 Break Out Board

Step 1: Connections

With many options for MCP23017 break out board available, there are few with proper wire to board connectors.
Spring cage connectors (Phoenix Contact 1990025) keep 20 - 26 AWG or 0.14 - 0.5 mm² wires securely in place. Power and I2C connector can be un-plugged for troubleshooting purposes.