custom mq135 api

lib/MQ135New/MQ135New.cpp

@@ -0,0 +1,59 @@
+#include "MQ135New.h"
+
+MQ135::MQ135(uint8_t pin) {
+  _pin = pin;
+}
+
+double MQ135::getRS() {
+    double voltage = getVoltage();
+    double RS = (double)((double)(VIn * RL) / voltage) - RL;
+    return RS;
+}
+
+double MQ135::getVoltage() {
+    int value = analogRead(_pin);
+    double voltage = (double)(value * VIn) / (double)(Resolution);
+    return voltage;
+}
+
+double MQ135::getPPM(float a, float b) {
+    double ratio = getRS() / R0;
+    // double ppm_log = (log10(ratio) - b) / a;
+    // double ppm = pow(10, ppm_log);
+    double ppm = a * pow(ratio, b);
+    return ppm;
+}
+
+double MQ135::getAcetona() {
+    return getPPM(34.668, -3.369);
+}
+
+double MQ135::getAlcohol() {
+    return getPPM(77.255, -3.18);
+}
+
+double MQ135::getCO2() {
+    // return getPPM(-0.3525, 0.7142) + ATMOCO2;
+    return getPPM(110.47, -2.862) + ATMOCO2;
+}
+
+double MQ135::getCO() {
+    return getPPM(605.18, -3.937);
+}
+
+double MQ135::getNH4() {
+    return getPPM(102.2, -2.473);
+}
+
+double MQ135::getTolueno() {
+    return getPPM(44.947, -3.445);
+}
+
+float MQ135::getR0() {
+    double r0 = getRS() / 3.6;
+    return r0;
+}
+
+void MQ135::setR0(float r0) {
+    R0 = r0;
+}

lib/MQ135New/MQ135New.h

@@ -0,0 +1,31 @@
+#ifndef MQ135New_H
+#define MQ135New_H
+
+#include "Arduino.h"
+
+#define RL 10
+#define VIn 5
+#define Resolution 1024
+
+#define ATMOCO2 397.13
+
+class MQ135 {
+ private:
+  uint8_t _pin;
+  float R0;
+  double getPPM(float a, float b);
+
+ public:
+  MQ135(uint8_t pin);
+  double getAcetona();
+  double getAlcohol();
+  double getCO();
+  double getCO2();
+  double getNH4();
+  double getTolueno();
+  float getR0();
+  void setR0(float r0);
+  double getRS();
+  double getVoltage();
+};
+#endif

platformio.ini

@@ -12,5 +12,6 @@
 platform = atmelavr
 board = megaatmega2560
 framework = arduino
-lib_deps =
-     adafruit/Adafruit BME280 Library @ ^2.1.2
+; lib_deps =
+;      adafruit/Adafruit BME280 Library @ ^2.1.2
+;      miguel5612/MQUnifiedsensor @ ^2.0.1

src/main.cpp

@@ -1,7 +1,5 @@
 #include <Arduino.h>
-#include <MQ135.h>
-#include <Adafruit_Sensor.h>
-#include <Adafruit_BME280.h>
+#include <MQ135New.h>
 
 #define PIN_MQ135 A0
 #define PIN_LED_GREEN DD2
@@ -12,83 +10,57 @@
 #define MEASURE_DELAY 1000
 #define NOISE_DELAY 100
 
-#define SEALEVELPRESSURE_HPA (1013.25)
-
-MQ135 co2_sensor = MQ135(PIN_MQ135);
-Adafruit_BME280 bme(10, 11, 12, 13);
-const int maxCount = MEASURE_DELAY / NOISE_DELAY;
-int count = -1;
-float ppm = 0;
-bool noise = false;
+MQ135 co2_sensor(PIN_MQ135);
 
 void setup() {
-  pinMode(PIN_MQ135, INPUT);
-  pinMode(PIN_LED_GREEN, OUTPUT);
-  pinMode(PIN_LED_YELLOW, OUTPUT);
-  pinMode(PIN_LED_RED, OUTPUT);
-  pinMode(PIN_NOISE, OUTPUT);
-
   Serial.begin(9600);
-
-  if (!bme.begin()) {
-    Serial.println(F("Could not find a valid BME280 sensor, check wiring!"));
-  }
+  pinMode(PIN_MQ135, INPUT);
+  co2_sensor.setR0(66.0);
 }
 
 void printValues(float ppm, float temp, float humidity);
 
 void loop() {
-  if (count >= maxCount || count < 0) {
-    float temp = bme.readTemperature();
-    float humidity = bme.readHumidity();
-    ppm = co2_sensor.getCorrectedPPM(temp, humidity);
+  float value = co2_sensor.getCO2();
+  Serial.println(value);
+  Serial.print("rs: ");
+  Serial.println(co2_sensor.getRS());
+  Serial.print("voltage: ");
+  Serial.println(co2_sensor.getVoltage());
+  delay(500);
+  // if (count >= maxCount || count < 0) {
+  //   float temp = bme.readTemperature();
+  //   float humidity = bme.readHumidity();
+  //   ppm = co2_sensor.getCorrectedPPM(temp, humidity);
     
-    count = 0;
-    if (ppm < 1000) {
-      digitalWrite(PIN_LED_GREEN, 1);
-      digitalWrite(PIN_LED_YELLOW, 0);
-      digitalWrite(PIN_LED_RED, 0);
-    }
-    else if (ppm <= 2000) {
-      digitalWrite(PIN_LED_GREEN, 0);
-      digitalWrite(PIN_LED_YELLOW, 1);
-      digitalWrite(PIN_LED_RED, 0);
-    }
-    else {
-      digitalWrite(PIN_LED_GREEN, 0);
-      digitalWrite(PIN_LED_YELLOW, 0);
-      digitalWrite(PIN_LED_RED, 1);
-    }
+  //   count = 0;
+  //   if (ppm < 1000) {
+  //     digitalWrite(PIN_LED_GREEN, 1);
+  //     digitalWrite(PIN_LED_YELLOW, 0);
+  //     digitalWrite(PIN_LED_RED, 0);
+  //   }
+  //   else if (ppm <= 2000) {
+  //     digitalWrite(PIN_LED_GREEN, 0);
+  //     digitalWrite(PIN_LED_YELLOW, 1);
+  //     digitalWrite(PIN_LED_RED, 0);
+  //   }
+  //   else {
+  //     digitalWrite(PIN_LED_GREEN, 0);
+  //     digitalWrite(PIN_LED_YELLOW, 0);
+  //     digitalWrite(PIN_LED_RED, 1);
+  //   }
 
-    printValues(ppm, temp, humidity);
-  }
+  //   printValues(ppm, temp, humidity);
+  // }
 
-  if (ppm > 2000) {
-    noise = !noise;
-    digitalWrite(PIN_NOISE, noise);
-  }
-  else {
-    digitalWrite(PIN_NOISE, 0);
-  }
+  // if (ppm > 2000) {
+  //   noise = !noise;
+  //   digitalWrite(PIN_NOISE, noise);
+  // }
+  // else {
+  //   digitalWrite(PIN_NOISE, 0);
+  // }
 
-  delay(NOISE_DELAY);
-  count++;
-}
-
-void printValues(float ppm, float temp, float humidity) {
-  Serial.print("Temperature = ");
-  Serial.print(temp);
-  Serial.println(" *C");
-
-  Serial.print("Humidity = ");
-  Serial.print(humidity);
-  Serial.println(" %");
-
-  Serial.print ("ppm = ");
-  Serial.println (ppm);
-
-  Serial.print ("rzero = ");
-  Serial.println (co2_sensor.getCorrectedRZero(temp, humidity));
-
-  Serial.println();
+  // delay(NOISE_DELAY);
+  // count++;
 }