The MCP23017, a 16-bit I2C GPIO expander, has always been a tasty chip. With 16 GPIOs addressable over I2C, proper push/pull outputs, software-enabled pull-ups, eight addresses, maskable ...

The ACTpro 200 is a two-door expander for use with the ACTpro 2000 and ACTpro 3000 Door Controllers. With a built-in, monitored 3 Amp power supply, the ACTpro 200 is designed to support two doors.