This USB Grove Adapter connects to your Linux, MacOS, or Windows computer and acts as a USB raw HID Remote I/O Protocol server. It brings out two Flexible I/O pins (and 3.3V and ground) to each of four Grove System connectors. The eight Flexible I/O pins are also brought out to a 2.54 mm pitch header (not included). Each of the eight Flexible I/O pins can be configured as a digital input or a digital output. Five pins can be configured as 10-bit analog inputs (0.0 to 3.3V). Two pins can be configured as an I2C bus master. Four pins can be configured as an SPI bus master.

The USB Grove Adapter is also available with original MCP2221A firmware. The MCP2221A firmware supports a virtual serial port on Grove connector J5 but it does not support SPI and has lower GPIO/ADC/I2C performance because it requires four HID reports for each operation. The Remote I/O Protocol Server firmware supports a single SPI slave device connected to Grove connectors J4 and J6 (header pins 4, 5, 8, 9) and has higher GPIO/ADC/I2C performance because it only requires two HID reports for each operation.