Adafruit BMP280 sparckfun I2C or SPI Barometric Pressure & Altitude Sensor (STEMMA QT)

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.

MQ4 High Sensitivity Gas Methane (CNG) Detector Sensor Module is a simple to use MQ-4 High Sensitivity Gas Methane (CNG) Detector Sensor Module which can sense the presence of Compressed Natural Gas(CNG), methane(CH4), etc in the air. The module uses our MQ-4 sensor. It simplifies the interface to the odd pin spacing of the sensor and provides the interface through standard 4 x 0.1″ header pins. It provides an analog output corresponding to the concentration of the gases in the air and an easy to use digital output. The onboard potentiometer can be used to set the maximum gas concentration beyond which the digital output gets triggered. Just power the module with 5V set the threshold and you can start getting the gas concentration of the air around the sensor! An onboard LED signals the presence of any gas.