MQ-7 sensor and ESP8266

[espruino-discuss]

Posted at 2018-01-26 by SankySyS

Hi Guys,

i have MQ-7 sensor like this https://www.pricerpro.com/amazon_items/b073n5d6zm-robotdyn-carbon-monoxide-co-gas-sensor-mq-7-for-diy-projects-arduino-stm32-raspberry-pi-analog-and-digital-out

Does anyone know how i can read data from this sensor via Digital pin?

[espruino-discuss]

Posted at 2018-01-26 by @MaBecker

Analog input on ESP8266 a very poor, but you can try.

There is a module for the MQ135 Air Quality Sensor , might be a good starting point.

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Posted at 2018-01-26 by DrAzzy

Does anyone know how i can read data from this sensor via Digital pin?

You cannot. The output is analog, not digital.

The analog input on the ESP8266 is pretty crap - but it does exist. Give that a try.

You could also use an external I2C or SPI ADC.

If you just care about it crossing a specific threshold, you could use a '393 to compare it with a reference voltage and drive a pin low when it's above (or below) that threshold.

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Posted at 2018-01-26 by SankySyS

Thank you! I will try