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--- amc2021:mq-135:start [2021/09/03 01:19] – created kshama001
+++ amc2021:mq-135:start [2021/09/03 18:47] (current) – removed kshama001
@@ Line 1: / Line 1: @@
-====== Important libraries used in the code ======
-<code>
-/**************************************************************************/
-/*!
-@file     MQ135.h
-@author   G.Krocker (Mad Frog Labs)
-@license  GNU GPLv3
-@section  HISTORY
-v1.0 - First release
-*/
-/**************************************************************************/
-#ifndef MQ135_H
-#define MQ135_H
-#if ARDUINO >= 100
- #include "Arduino.h"
-#else
- #include "WProgram.h"
-#endif
-/// The load resistance on the board
-#define RLOAD 10.0
-/// Calibration resistance at atmospheric CO2 level
-#define RZERO 65
-/// Parameters for calculating ppm of CO2 from sensor resistance
-#define PARA 116.6020682
-#define PARB 2.769034857
-</code>
-  *Rzero is the value of the resistor in the MQ-135 sensor in the presence of clean air. Where the CO <sub>2</sub> value is around 397.13 ppm as given below. The Rzero value varies for each individual sensor and can be found using another Arduino code
-  *RLOAD meanwhile is the external resistor value that is connected to the MQ-135 sensor, which in this case is 10kΩ.
-  *Important parameters are for calculating CO<sub>2</sub> of 116.6 and 2.79 are taken from a calibration graph. This is already predefined for each gas that MQ-135 detects. amc2021:extras:screenshot_2021-09-03_at_01.11.54.png
-<code>
-/// Parameters to model temperature and humidity dependence
-#define CORA 0.00035
-#define CORB 0.02718
-#define CORC 1.39538
-#define CORD 0.0018
-/// Atmospheric CO2 level for calibration purposes
-#define ATMOCO2 397.13
-class MQ135 {
- private:
-  uint8_t _pin;
- public:
-  MQ135(uint8_t pin);
-  float getCorrectionFactor(float t, float h);
-  float getResistance();
-  float getCorrectedResistance(float t, float h);
-  float getPPM();
-  float getCorrectedPPM(float t, float h);
-  float getRZero();
-  float getCorrectedRZero(float t, float h);
-};
-#endif
-</code>