MQ-4 Gas Methane Sensor

Specifications:
Electrical properties:
The input voltage: DC5V power consumption (current) : 150 ma
The DO output: TTL digital quantity 1 s and 0 s (0.1 and 5 v)
AO output: 0.1-0.3 V (pollution-free), the highest concentration of voltage is 4 V or so

Connection mode:
1. VCC: Positive (5 v)
2. GND: Connect power negative
3. DO: TTL switch signal output
4. AO: Analog signal output