Change heating time about arduino-mq131-driver

[ostaquet]

Hi,
The time required to read the value is depending on the sensor. This kind of sensor is working by burning gas with the heather and measuring the concentration of some specific particles after a specific heating time.

The default heating time is 72s with the low concentration version and 80s with the high concentration version.

It is defined in the constructor of the driver:
// Setup default calibration value switch(model) { case LOW_CONCENTRATION : setR0(110470.60); setTimeToRead(72); break; case HIGH_CONCENTRATION : setR0(385.40); setTimeToRead(80); break; }

Those default values have been defined by experiments on the device I own.

The "time to read" should be the delay between the start of the heater and the moment when the value is stable. If you decide to measure the value of the device after 5 seconds, the value will be erroneous. The best way to define the correct value is to use the method calibrate().

After the calibration, you are able to read the value defined by the calibration with the method getTimeToRead() and you can change manually this heating time with the method setTimeToRead(long sec).

Kind regards,
Olivier