USB to SPI Bridge And Bootstrap Loader (video) 10:19 am July 13, 2016 By Julian Horsey ...

It features a USB 2.0 full-speed controller and transceiver, SPI controller (enabling communication with SPI slave devices down to 1.8 V), 348-byte programmable memory, crystal-less USB operation ...

He used that component to craft his own USB to RS-485 bridge. RS-485 is often used for remote sensors as it provides a method of connecting electronics over long distances.

Specifications of the USB2 High-Speed Hub : – 4x USB2 High Speed (480 mbps) downstream ports – 1x USB2 High Speed (480 mbps) upstream port – 5th endpoint on USB hub exposes I2C, SPI, UART ...

Compliant with the USB 2.0 hi-speed standard, this is a feature-rich single chip bridging solution with I²C and multi-channel SPI interface capabilities.

This would be perfect for making a couple-key keyboard, a USB-USART or USB-SPI bridge, or even a volume control knob — one ADC pin seems to be broken out.