BETAConnect and reset
Power, bypass and reset the IC; ground A2–A0 and connect I²C.
16-bit register-controlled I²C port expander
MCP23017 Basic Circuit
Build a basic MCP23017 circuit with labeled pins, component values and connection guidance.
Package view
MCP23017 in a circuit
A defined startup sequence and captured input changes.
Connect it, step by step
Follow the component values and pin connections
Set directions
Preload latches, then set IODIRA 7E and IODIRB 7F. Both bit-7 pins remain outputs.
Drive and read
Write OLATA bit0 for the LED; read GPA1 or captured port A state for the button.