MQ-2 Sensor. about esphome-core HOT 5 CLOSED

These are just analog sensors - they give the gas value as an analog voltage reading. So the adc sensor supports MQ-2s already. All you need will be to come up with a formula that converts the analog voltage reading to a gas reading (for example from datasheet)

Please see TEMT6000 example for how to do this.

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Thanks for the quick response and information. And one little questin.
In my sensors sketch:
`float BaseMQ::calculateResistance(int rawAdc) const {
// float vrl = rawAdc*(5.0 / 1023); // Так по класcике
float vrl = rawAdc * (5.0 / 1551); // Так у нас
float rsAir = (5.0 - vrl) / vrl * getRL();
if (_corr_factor_set) {
rsAir = rsAir / _corr_factor;
}
Help me write the formula for - lambda correctly
Thx.

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It's not too hard to convert it. You can pretty much copy paste it:

float vrl = x * 5.0;
// you didn't post getRL method, so no way I know what that does
float rsAir = (5.0 - vrl) / vrl * getRL();
return rsAir;

Also I can tell you your formula is probably wrong. The * 5.0 looks a lot like you're using 5V voltage level, but the ESP operates at 3.3V which would require you to use some external circuitry to scale the voltage.

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This sensor works from 5 volts (as far as I know), but the terminal gives 5.0 volts
getRL - This probably means
protected:
unsigned long readScaled(float a, float b) const;
virtual float getRoInCleanAir() const = 0;
virtual int getRL() const = 0;
And
private:
// Резистор установленный на плату (кОм)
virtual int getRL() const { return 1; }
// коэффициент чистого воздуха
virtual float getRoInCleanAir() const { return 9.83; }

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Based on my experience, the analgo reader of the ESP8266 doesn't sit along well with the MQ2. I had better luck using an arduino as an I2C slave, reading the sensors with that and then the i2C to the ESP8266

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