CH340C USB-UART converter that is a USB to UART bridge
CH340C is a USB-UART converter that is a USB to UART bridge that is popular due to its low price. It is made in China and is found on most Chinese versions of Arduino. The C version has the advantage of not needing an external oscillator. CH340 can be used to upgrade serial interface peripherals or expand extra serial ports for computers via USB bus. It supports 5V and 3.3V power voltage, and can provide common MODEM liaison signal in serial UART mode.