After all, I2C (that is, SMBus) is one of the interfaces that is highly likely to be used on your PC’s mainboard ... physical adapter to add a USB-connected I2C interface to a system.

It’s a dual USB ... his computer, and get it all done in inexpensive hardware with minimal fuss. So he looked to the Microchip MCP2221 chip, which is an inexpensive USB to serial and I2C chip ...