This paper contains the information of a CNC milling machine firmware development for PCB manufacturing, using an Arduino UNO board to control, with a USB connectivity between the machine and regular PC. The firmware was tested with a boundary obtaining software, developed to get the boundary of a circuit path provided by Proteus® in the Geber RS-274X format and send each coordinate of circuit boundary through serial communication. This firmware will allow PCB manufacturers to build their own machines in less time and with less cost, and use them using regular PCs.