This is a breakout board for MQ8, a simple-to-use hydrogen gas sensor, suitable for sensing hydrogen concentrations in the air. The MQ-8 can detect hydrogen gas concentrations anywhere from 100-10000ppm. It is designed to have two outputs: digital one and analog one.
The digital TTL is active low, and when it outputs low level signal, the LED will turn on.
The analog output will output a voltage that is proportional to the concentration of the hydrogen gas.
Input voltage: DC 5V and rated current is 150mA.
Digital output (D0): TTL 0 (0.1V) and 1 (5V). The threshold can be tuned.
Analog output (A0): 0.1-0.3V when there is no hydrogen, and 4V when the contration is really high.
After power it on, it needs to be pre-heated for 20S before the measurement can be stable.