This FeatherWing is a I2C GPIO Expander which give 16 gpio pins on the Feather bus controlled from the I2C bus.
It also has interrupt capabilities so that if put into read mode the interrupt pin will rise and fall accordingly. This pin is connected to GPIORX of the feather bus.
The FeatherWing also has a Watchdog chip that needs to be kicked on the GPIOTX pin on the Feather Bus. This will toggle the reset line if not kicked within a set amount. Current setting is at 1 minute, but can be reduced to 10ms if required.
Working in conjunction with the Octo Board the controller can be used to disable other FeatherWings and to allow Interrupts to be consolidated into one Interrupt pin and thus allowing pin savings.
Each Interrupt pin on read has an external pull up resistor.
Note: This FeatherWing is sold as a Kit and the pins required to be soldered. A pre-soldered version is available.