Zak’s Electronics Blog published a new library and breakout board for MCP2221 USB to UART interface IC:
This is a library for interfacing with the HID features of the MCP2221 USB to UART and I2C/SMBus serial converter from Microchip. The converter includes 4 GPIO pins, 3x 10-bit ADCs, 1x 5-bit DAC and more. Microchip does provide a library for interfacing with the chip, however it is supplied as proprietary DLLs. This project aims to be an open-source and multi-platform alternative. libraryThis library also makes use of HIDAPI.
MCP2221 HID Library – [Link]