Add 16 digital GPIOs to an ESP32 with the MCP23017 I2C expander. ESPHome wiring, addresses, pull-ups, interrupts, multiple chips, Home Assistant and troubleshooting.
Compare MCP23017, PCF8574 and PCF8575 GPIO expanders for ESP32 and ESPHome: pin count, I2C speed, interrupts, pull-ups, relay and button use, wiring and example YAML.