CP2102 chip from SiLabs is a single-chip USB to UART bridge IC. This cp2102 USB to serial requires minimal external components.CP2102 can be used to migrate legacy serial port based devices to USB.

MQ3 MQ 3 MQ-3 Alcohol Detector Gas Sensor Module is a simple to use MQ-3 Alcohol Detector Gas Sensor Module which can sense the presence of Alcohol in the air. The module uses our MQ-3 sensor. It simplifies the interface to the odd pin spacing of the sensor and provides an interface through standard 4 x 0.1″ header pins. It provides an analog output corresponding to the concentration of the gas 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. Perfect sensing alcohol concentration on your breath just likes common breathalyzer. mq3 alcohol sensor working

RS485 to TTL / TTL to RS485 converter is a module that allows the TTL interface of the microcontroller to be transferred to the RS485 module / MAX485 module. It is generally used for industrial automation. This module adds lightning protection design and anti-jamming design. When we use it in the field and carry out long distance transmission, we can Connect the GND end of the module to the ground so that lightning protection and anti-interference can be achieved. This Max485 to TTL module is online in Pakistan