USB ports can be used in many applications in the field of electronics. However, unlike the RS232 interface, devices have not become available to interconnect USB and parallel ports. This general-purpose USB UART now rectifies that situation.Just as the legendary AY-3-1015 UART converts between parallel and RS232 interfaces, this Elektor Electronics USB chip provides general-purpose ports accessible over USB. The only extra components required to build a complete USB device are a ceramic resonator or quartz crystal and a couple of capacitors. In total twelve port connections are available, which can freely be written and read. Further, the output current can be set for each port connection, which allows, for example, the brightness of a connected LED to be controlled directly.