There is a USB port on the front of the Quarto, right next to the SD card slot, that I cannot find any explanation for. I tried plugging into it to see if it was a serial connection, but no dice. Is it an optional USB storage slot? Does it allow cross-linking between Quartos? Is it unconnected and just there for a possible future use? Does it act as a UART connection to the board that can be programmed within the Arduino IDE?