FT-MOD-4232HUB was selected as the I/O expansion module to bridge the USB port of the RPi2 to the peripheral components. The module is designed with an FT4232H USB-to-4-channel bridge IC. It is able to use one channel to convert USB to I²C for the sensors and another for converting USB to SPI for the display module, using a device mode known as MPSSE. Downstream USB ports available on the module are not used.