USB to TTL Serial like the PL2303 USB is commonly used as an intermediate medium for uploading programs. You can see the wiring between the PL2303 USB and the Arduino Pro Mini board in the picture ...

An Arduino is a popular open-source single-board microcontroller. Learn how to program one and let the possibilities take shape.

Instructables user Ardumotive_com has published a new project that explains how to create your very own Arduino powered mini CNC plotter.