1.5V and 5V cycle for sensors like MQ7

[amirsalman93]

If you look at the datasheet of MQ7, It requires a periodic cycle of 5V (Release State for 60 seconds) and 1.5V (Absorb state for 90 seconds) to operate correctly.

Source: https://www.sparkfun.com/datasheets/Sensors/Biometric/MQ-7.pdf

Can you please add it to the library?
Thanks

[miguel5612]

According to:
[https://forum.arduino.cc/index.php?topic=204036.0](Calculating PWM Duty Cycles)

A TRMS instrument would show you sqrt(12^2*0.25) = 6V

This means, using a sqrt(5^2*0.08) = sqrt(2) = 1.4142135 -> DutyCycle 8% is equal to 1.41 Volts aprox
And according to:
https://forum.arduino.cc/index.php?topic=567771.0
Heater could be conected using a mosfet (IRLZ34N)

Note: if you are going to do this practice with a nodeMCU, ESP8266 or ESP32, you must place the voltage divider at the output so that your output range reaching pin A0 of your arduino is between 0 and 3V3
Code: We will update MQ7 - MQ-309 examples.