MQ2 Smoke sensor - Deep Sleep? Analog or Digital

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MQ2 Smoke sensor - Deep Sleep? Analog or Digital

#1 Post by Dynalon » 26 Jun 2020, 19:00

Hello everybody,

first I want to thank everybody for this great project. I am quite new in FHEM, have no abilities in programming and I read about ESP8266 and ESPEasy less than 3 weeks ago.

Now I have a great (or greately? Sorry, I am not a native Speaker, but therefore I accept German answers, too) working Temperature sensor node which is together with my Raspberry controlling whole solarthermic heating system of our small pool by measuring several critical points in the system and switching on and off several key units by temperature. I also have a - nicely working but still not perfect - smoke sensor.

Right now I am using an ESP D1 Mini, which is connectec with a MQ2 Smoke sensor, like below:

MQ2 Connectors: D1 Mini Connectors:

VCC ----------------------------------------------------5V

3,3 kOhm
Analog out ----1,8kOhm-----------------------------AO

The D1 Mini is right now flashed with ESP_Easy_mega-20191208_normal_ESP8266_4M1M.bin, which is right now running quite nicely for me.

Now my problem: I do not need a continous measurement, and in fact a number is nice, but actually the values "Smoke" and "No Smoke", would be enough, too. Additionally it would be nice to get the D1 Mini in Deep Sleep and measure once per minute. This also would reduce the temperature.

So here are my questions, I hope you can help me:

- Why is my D1 Mini not going to Deep sleep? At least the LED on MQ2 is never switching off and it is >36 Degrees (Mq2 and D1 Mini are this!) all the time.

- Could I solve this problem by using only the MQ2 digital out? What device should I choose then? I see nothing like "MQ1, MQ2, MQ135, Gas sensor, smoke sensor,..." in the dropdown menu.

Thanks a lot!

Best regards Dynalon

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Re: MQ2 Smoke sensor - Deep Sleep? Analog or Digital

#2 Post by TD-er » 26 Jun 2020, 22:46

Please try the sleep mode without any sensor connected.
To wake up you need to connect GPIO-16 to RST.
You can try to trigger a GPIO-pin at boot (in the rules) and connect a LED to it to see if it reboots.

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