Introduction: MCP23017 Break Out Board IOBOB

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


  • 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)


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.

Step 2: Mounting

Mounts to standard 35 mm DIN rail and 30 mm C-rail.