Some of the terms used in this tutorial are shown on this slide. The Universal Asynchronous Receiver Transmitter or UART as it is commonly known is a serial communication circuit used in legacy PCs and devices which operates at data rates from 75 bps to 3 Mbps. The next term is Full speed USB, Universal Serial Bus, which is the operating standard that operates at 12 Mbps. A Communications Device Class or CDC driver is software which is loaded onto a PC; it will identify a USB connected device and treat it like a UART device. Vendor Identification Number (VID) and Product Identification Number (PID). VID is a 16-bit number assigned to a member company by the USB implementers forum. This is a unique ID that is assigned to each and every company. PID is a 16-bit number assigned to a USB product by its manufacturer. Various different products from each manufacturer carry different PIDs. Windows Hardware Quality Lab (WHQL) testing is a Microsoft testing process that involves a series of compatibility tests for third party hardware or software. A Recommended Standard 232 (RS232) level shifter is an IC that generates voltage levels sufficient to drive UART standard signals over long cables, at lengths of as much as 300 m. Lastly, USB-IF battery charging revision 1.2 is a specification established by the USB implementers forum for charging USB devices at various currents.