Merge pull request #33 from Yoimer/fix-esp32-measuring-issue-when-connected-to-wifi

added esp32-wroom-32d board, fixed the measuring issue when connected…

README.md

@@ -81,13 +81,15 @@ float ppmCH4 = MQ4.readSensor();
 ### ESP8266-ESP32
 ![ESP8266_Wiring_MQSensor](https://raw.githubusercontent.com/miguel5612/MQSensorsLib_Docs/master/static/img/MQ_ESP8266.PNG)
 
+### ESP32 WROOM 32D
+The ESP32 WROOM 32D does not need an external power supply. A0 goes to PIN36, Vcc to 3v3 and GND to any GND port on the board. Check the **ESP2/ESP32_WROOM_32** folder to fixing the measuring issue when connecting to wifi.
+
 ### Manuals
 #### User Manual (v1.0) 12.2019
 [Manual](https://drive.google.com/open?id=1BAFInlvqKR7h81zETtjz4_RC2EssvFWX)
 #### User Manual (v2.0) 04.2020
 [Manual](https://github.com/miguel5612/MQSensorsLib_Docs/blob/master/Docs/MQSensorLib_2.0.pdf)
 
-
 ### Serial debug (optional)
 If your sensor is an **MQ2** (Same for others sensors):
 * To enable on setup wrote

examples/ESP32/ESP32_WROOM_32D/ESP32_WROOM_32D.ino

@@ -0,0 +1,136 @@
+/*
+ *  This sketch fixes the MQ2 measuring issue when using Wifi.h
+ *  Wifi.h deactivates pin 25 analogical input on esp32.ino default sketch.
+ *  This is because Wifi.h works only with ADC1 for analogical measurement
+ *  Please check the esp32-wroom-32d.jpg image on ESP32 folder
+ * 
+
+ * ADC1 GPIO
+ * ADC1_CH0 (GPIO 36) // only tested on this and it works as expected :)
+ * ADC1_CH1 (GPIO 37)
+ * ADC1_CH2 (GPIO 38)
+ * ADC1_CH3 (GPIO 39)
+ * ADC1_CH4 (GPIO 32)
+ * ADC1_CH5 (GPIO 33)
+ * ADC1_CH6 (GPIO 34)
+ * ADC1_CH7 (GPIO 35)
+ *
+ * ADC2 GPIO
+ * ADC2_CH0 (GPIO 4)
+ * ADC2_CH1 (GPIO 0)
+ * ADC2_CH2 (GPIO 2)
+ * ADC2_CH3 (GPIO 15)
+ * ADC2_CH4 (GPIO 13)
+ * ADC2_CH5 (GPIO 12)
+ * ADC2_CH6 (GPIO 14)
+ * ADC2_CH7 (GPIO 27)
+ * ADC2_CH8 (GPIO 25)
+ * ADC2_CH9 (GPIO 26)
+ *
+ */
+
+
+#include <WiFi.h>
+
+//Include the library
+#include <MQUnifiedsensor.h>
+/************************Hardware Related Macros************************************/
+#define         Board                   ("ESP-32") // Wemos ESP-32 or other board, whatever have ESP32 core.
+
+//https://www.amazon.com/HiLetgo-ESP-WROOM-32-Development-Microcontroller-Integrated/dp/B0718T232Z (Although Amazon shows ESP-WROOM-32 ESP32 ESP-32S, the board is the ESP-WROOM-32D)
+#define         Pin                     (36) //check the esp32-wroom-32d.jpg image on ESP32 folder 
+
+/***********************Software Related Macros************************************/
+#define         Type                    ("MQ-2") //MQ2 or other MQ Sensor, if change this verify your a and b values.
+#define         Voltage_Resolution      (3.3) // 3V3 <- IMPORTANT. Source: https://randomnerdtutorials.com/esp32-adc-analog-read-arduino-ide/
+#define         ADC_Bit_Resolution      (12) // ESP-32 bit resolution. Source: https://randomnerdtutorials.com/esp32-adc-analog-read-arduino-ide/
+#define         RatioMQ2CleanAir        (9.83) //RS / R0 = 9.83 ppm
+/*****************************Globals***********************************************/
+MQUnifiedsensor MQ2(Board, Voltage_Resolution, ADC_Bit_Resolution, Pin, Type);
+/*****************************Globals***********************************************/
+
+const char* ssid     = "your-ssid";
+const char* password = "your-password";
+
+void setup()
+{
+
+  //Init the serial port communication - to debug the library
+  Serial.begin(115200); //Init serial port
+  delay(10);
+
+  //Set math model to calculate the PPM concentration and the value of constants
+  MQ2.setRegressionMethod(1); //_PPM =  a*ratio^b
+  MQ2.setA(987.99); MQ2.setB(-2.162); // Configurate the ecuation values to get H2 concentration
+  
+/*
+    Exponential regression:
+    Gas    | a      | b
+    H2     | 987.99 | -2.162
+    LPG    | 574.25 | -2.222
+    CO     | 36974  | -3.109
+    Alcohol| 3616.1 | -2.675
+    Propane| 658.71 | -2.168
+  */
+
+  /*****************************  MQ Init ********************************************/ 
+  //Remarks: Configure the pin of arduino as input.
+  /************************************************************************************/ 
+  MQ2.init(); 
+ 
+  /* 
+    //If the RL value is different from 10K please assign your RL value with the following method:
+    MQ2.setRL(10);
+  */
+  /*****************************  MQ CAlibration ********************************************/ 
+  // Explanation: 
+  // In this routine the sensor will measure the resistance of the sensor supposing before was pre-heated
+  // and now is on clean air (Calibration conditions), and it will setup R0 value.
+  // We recomend execute this routine only on setup or on the laboratory and save on the eeprom of your arduino
+  // This routine not need to execute to every restart, you can load your R0 if you know the value
+  // Acknowledgements: https://jayconsystems.com/blog/understanding-a-gas-sensor
+  Serial.print("Calibrating please wait.");
+  float calcR0 = 0;
+  for(int i = 1; i<=10; i ++)
+  {
+    MQ2.update(); // Update data, the arduino will be read the voltage on the analog pin
+    calcR0 += MQ2.calibrate(RatioMQ2CleanAir);
+    Serial.print(".");
+  }
+  MQ2.setR0(calcR0/10);
+  Serial.println("  done!.");
+  
+  if(isinf(calcR0)) {Serial.println("Warning: Conection issue founded, R0 is infite (Open circuit detected) please check your wiring and supply"); while(1);}
+  if(calcR0 == 0){Serial.println("Warning: Conection issue founded, R0 is zero (Analog pin with short circuit to ground) please check your wiring and supply"); while(1);}
+  /*****************************  MQ CAlibration ********************************************/ 
+  //MQ2.serialDebug(true); uncomment if you want to print the table on the serial port
+
+    // We start by connecting to a WiFi network
+
+    Serial.println();
+    Serial.println();
+    Serial.print("Connecting to ");
+    Serial.println(ssid);
+
+    WiFi.begin(ssid, password);
+
+    while (WiFi.status() != WL_CONNECTED) {
+        delay(500);
+        Serial.print(".");
+    }
+
+    Serial.println("");
+    Serial.println("WiFi connected");
+    Serial.println("IP address: ");
+    Serial.println(WiFi.localIP());
+}
+
+void loop()
+{
+  MQ2.update(); // Update data, the arduino will be read the voltage on the analog pin
+  //MQ2.serialDebug(); // Will print the table on the serial port
+  Serial.print(MQ2.readSensor()); // Sensor will read PPM concentration using the model and a and b values setted before or in the setup
+  Serial.println(" PPM");
+  delay(500); //Sampling frequency
+}
+

library.properties

@@ -6,5 +6,5 @@ sentence= This library allows you to read the MQ sensors very easily.
 paragraph= This library allows an Arduino/Genuino/ESP8266 board to read MQ Sensors (AIr quality meter) references: MQ2, MQ3, MQ4, MQ5, MQ6, MQ7, MQ8, MQ9, MQ131, MQ135, MQ303A, MQ309A.
 category= Sensors
 url=https://github.com/miguel5612/MQSensorsLib
-architectures=avr
+architectures=avr,esp8266,esp32
 license=MIT