This is PL2303 CH340G USB To TTL(Serial) Converter For Arduino Nano Raspberry Pi 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, and has the option to switch from 5V to 3.3V logic level using a 2 pin shunt (shortening jumper for specific pins) supplied with the module.

MQ8 MQ 8 MQ-8 Hydrogen Gas Sensor Module H2 Alarm Detection MQ-8 Sensor Hydrogen Gas Sensor Module H2 Alarm Detection use in clean air low conductivity tin oxide (SnO2). When there is the environment in which the combustible gas sensor, conductivity sensor with increasing concentration of combustible gases in air increases. Using a simple circuit to convert the change in conductivity of the gas concentration corresponding to the output signal. MQ-8 hydrogen gas sensor of high sensitivity, the monitoring of the other hydrogen-containing gas is also very satisfactory. This sensor can detect a wide range of hydrogen gas, city gas, in particular, is a low-cost sensor for a variety of applications.