Refactor MQ7 sensor implementation: remove old files and introduce MQ7v2 with updated reading logic

hardware/include/MQ7.hpp

@@ -1,8 +0,0 @@
-#include <Arduino.h>
- 
-#define HEATER_PIN 16
-#define SENSOR_PIN 34
-
-void MQ7_Init();
-void MQ7_Read(float &sensorValue);
-void pwmBitBang(int totalMs, int highPct, int cycleMs);

hardware/include/MQ7v2.hpp

@@ -0,0 +1,10 @@
+#include <Arduino.h>
+
+#define MQ7_PIN 34
+#define VCC 5.0
+#define ADC_RES 1023.0
+#define RL 10000.0     // 10kΩ
+#define RO 10000.0     // Resistencia del aire limpio
+
+void MQ7_Init();
+void MQ7_Read(float &sensorValue);

hardware/include/main.hpp

@@ -11,7 +11,7 @@
 #include "BME280.hpp"
 #include "GPS.hpp"
 #include "MAX7219.hpp"
-#include "MQ7.hpp"
+#include "MQ7v2.hpp"
 
 uint32_t getChipID();
 void prettyReadMQ7();

hardware/src/lib/sensor/MQ7.cpp

@@ -1,45 +0,0 @@
-#include "MQ7.hpp"
-
-void MQ7_Init()
-{
-  pinMode(HEATER_PIN, OUTPUT);
-  pinMode(SENSOR_PIN, INPUT);
-}
-
-void MQ7_Read(float &sensorValue)
-{
-  Serial.println("\t - Calentando MQ7");
-  digitalWrite(HEATER_PIN, HIGH);
-  delay(60000);
-
-  Serial.println("\t - Enfriando MQ7");
-  pwmBitBang(90000, 28, 100);
-
-  const int N = 1;
-  long sum = 0;
-  for (int i = 0; i < N; i++)
-  {
-    sum += analogRead(SENSOR_PIN);
-    delay(5);
-  }
-
-  sensorValue = sum / float(N);
-  //sensorVolt = sensorValue * (3.3 / 4095.0); // ADC 12 bits, 3.3V
-}
-
-// generamos PWM por software usando bit banging
-void pwmBitBang(int totalMs, int highPct, int cycleMs)
-{
-  int onTime = cycleMs * highPct / 100;
-  int offTime = cycleMs - onTime;
-  int elapsed = 0;
-  
-  while (elapsed < totalMs)
-  {
-    digitalWrite(HEATER_PIN, HIGH);
-    delay(onTime);
-    digitalWrite(HEATER_PIN, LOW);
-    delay(offTime);
-    elapsed += cycleMs;
-  }
-}

hardware/src/lib/sensor/MQ7v2.cpp

@@ -0,0 +1,23 @@
+#include "MQ7v2.hpp"
+
+void MQ7_Init()
+{
+    pinMode(MQ7_PIN, INPUT);
+}
+
+void MQ7_Read(float &sensorValue)
+{
+    int adcValue = analogRead(MQ7_PIN);
+    float voltage = (adcValue / ADC_RES) * VCC;
+
+    if (voltage <= 0.1) {
+        sensorValue = 0;
+        return;
+    }
+
+    float rs = (VCC - voltage) * RL / voltage;
+    float ratio = rs / RO;
+    float ppm = pow(10, (-1.5 * log10(ratio) + 0.8));
+
+    sensorValue = ppm;
+}

hardware/src/main.cpp

@@ -11,8 +11,6 @@ extern MD_Parola display; // Display object
 
 void setup()
 {
-    /*GPS_Init();
-    Serial.println("GPS inicializado"); */
     Serial.begin(9600);
 
     Serial.println("Iniciando...");
@@ -23,9 +21,18 @@ void setup()
     MQ7_Init();
     Serial.println("Sensor MQ7 inicializado"); 
 
+    /*
+    GPS_Init();
+    Serial.println("GPS inicializado");
+    */
+
     prettyReadBME280();
     testMatrix();
     prettyReadMQ7();
+
+    /* 
+    
+    */
 }
 
 void loop()
@@ -40,7 +47,6 @@ void prettyReadMQ7()
 {
     Serial.println("Leyendo sensor MQ7...");
     MQ7_Read(sensorValue);
-    //Serial.print("\t - Voltaje: "); Serial.print(sensorVolt); Serial.print("V\r\n");
     Serial.print("\t - Valor sensor: "); Serial.print(sensorValue); Serial.print("\r\n");
 }