Giovanni Bernardo is back with another build, this time using a Microchip MCP221A — "a PIC16F1455 in another dress," he explains — to create a UART and I2C USB bridge compatible with Windows, macOS, Linux, and even Android.
"I don't know if I would have been better to call this project a Serial/USB Adapter to make it better indexed on Google," Bernardo notes, "but the fact is that it is not just this: the device that I present allows in fact to communicate, and therefore also run simple debugging operations, even on an I2C bus or SMBus."
The heart of the system is the Microchip MCP2221A, chosen as a lower-cost alternative to the FTDI FT232R which could have otherwise been used in the project. "The MCP2221A, in addition to the price, has two more aces up its sleeve," Bernardo continues. "It exists in DIP format, and I think it is the only USB to UART device existing in this format (correct me if I'm wrong) and I personally appreciate it very much, and it supports communication as a master on the I2C bus."
Mounted onto a custom PCB produced by PCBWay, the resulting gadget is compatible with a range of operating systems — including, using a suitable USB On-The-Go (OTG) adapter, Android smartphones and tablets. The latter includes support for Microchip's own MCP2221 Terminal Android application — which allows for communication over UART or I2C while out and about.
Bernardo's full write-up, including information about using the device on other operating systems, is available on his website SetorreZero.com.