Smoke sensor MQ2 (Digital/Analog)

From the shop's description

This smoke sensor module with MQ2 Smoke sensor have both digital and analog outputs , you also can adjust the sensitivity with the potentioneter. PIN Connection 4 pins as follows: VCC (5 V) GND (ground) Aout (Analog output) Dout (Digital output) When connect to arduino, use digital pins in digital mode (high or low) and use analog pins for analog mode (diffrenet value for different smoke intensity).