ESP8266 Community Forum

- Wed Dec 02, 2015 11:37 am #35517 I'm wondering how to handle 5V sensors at the NodeMCU ESP-12E modules
For example the MQ3 alcohol sensor needs 5v for heating up the sensor before use:
http://nl.aliexpress.com/item/For-1PC-MQ3-MQ-3-Alcohol-Ethanol-Sensor-Breath-Gas-Detector-Detection-For-Arduino/32524841317.html?ws_ab_test=searchweb201556_7_79_78_77_80_61,searchweb201644_5,searchweb201560_10
I did read that using the 5V on the NodeMCU will cause resets of the Node (Is it true?)
I can imagine that you use an external 5V power supply special for this sensor. But I'm wondering how to connect the Anologe output to the NodeMCU in combination with this 5V power supply?. Because the reference of the signal is based on the 5V from the sensor?
Is there somewhere a wiring example to show how this will work?
I do appreciate all answers

- Wed Dec 02, 2015 12:48 pm #35522 Here you go - http://www.b4x.com/android/forum/thread ... nsor.58266
Thanks to ESP8266 forum member freedom2000
Krzysztof

- Wed Dec 02, 2015 1:28 pm #35525

Here you go - http://www.b4x.com/android/forum/thread ... nsor.58266
Thanks to ESP8266 forum member freedom2000
Krzysztof

Thanks. Quite more complex as I expected

- Wed Dec 02, 2015 1:43 pm #35526

But I'm wondering how to connect the Anologe output to the NodeMCU in combination with this 5V power supply?. Because the reference of the signal is based on the 5V from the sensor?

Try this nice tutorial by Afrotechmods (my another favourite - master of brevity ) - https://www.youtube.com/watch?v=XxLKfAZrhbM

Hope this clarifies your concern's how to connect the Anologe output to the NodeMCU's ADC input.

Krzysztof