TCS3200 is a static object colour detection chip which can output different frequency based on different colour sensed and then MCU can read the RGB colour via frequency collection and conversion.
MQ-4 gas sensor modules are used in gas leakage detecting equipments in family and industry, are suitable for detecting of CH4,Natural gas.LNG, avoid the noise of alcohol and cooking fumes and cigarette smoke.
This alcohol sensor is suitable for detecting alcohol concentration on your breath, just like your common breathalyzer. It has a high sensitivity and fast response time. Sensor provides an analog resistive output based on alcohol concentration. The drive circuit is very simple, all it needs is one resistor. A simple interface could be a 0-3.3V ADC.
This semiconductor gas sensor detects the presence of LPG, isobutane, and propane at concentrations from 300 to 10,000 ppm. The sensor’s simple analog voltage interface requires only one analog input pin from your microcontroller.