This is CH340G USB To TTL(Serial) Converter, USB to TTL / USB-TTL /STC microcontroller programmer / PL2303 in nine upgrades plate with a transparent cover Compatible with ARDUINO, RASPBERRY PI, AVR, PIC, 8051, etc.
This USB–TTL converter is based on CH340G USB to Serial TTL converter chip. The module can be used for 3.3V logic level signals, the and has the option to switch from 5V to 3.3V logic level using a 2 pin shunt supplied with the module.
The CH340 USB to serial adaptor makes use of the CH340 USB to serial IC to provide a low-cost alternative to our popular FTDI based module. Although much cheaper this module doesn’t lack in features or usability. Once you have installed the drivers the module will appear as a normal serial COM port on your computer making it compatible with most terminal programs and development environments such as the Arduino IDE.
The module includes a small switch which allows the voltage available at the VC (Supply output) pin to be switched between 3.3 and 5V. Data pins include TX, RX. These digital pins are at 5V TTL levels allowing them to be directly interfaced most 5V microcontrollers.