[MQ2] Gas sensor & tweak DHT config to avoid editing source when PIN is different (#1576)

Add MQ2 Gas sensor & tweak DHT config to avoid editing source when PIN is different

docs/prerequisites/board.md

@@ -4,7 +4,7 @@ OpenMQTTGateway is not closed to one board or type of board, by using the power
 
 You can take a look to the [OpenMQTTGateway compatible website](https://compatible.openmqttgateway.com) to have a view of the [supported boards](https://compatible.openmqttgateway.com/index.php/boards/).
 
-Moreover the gateways capacities can be extended with sensors; DHT, HC SR501, ADC, I2C bus, INA226, TEMT6000, TSL2561, BME280/BMP280, HTU21D, AHTx0, DS1820
+Moreover the gateways capacities can be extended with sensors; DHT, HC SR501, ADC, I2C bus, INA226, MQ2, TEMT6000, TSL2561, BME280/BMP280, HTU21D, AHTx0, DS1820
 or actuators; LED, relays, PWM.
 
 ::: tip Running on a computer

docs/setitup/sensors.md

@@ -12,6 +12,7 @@
 |GPIO Input|Inputs|-|
 |GPIO KeyCode|Keycode|[parts list](https://compatible.openmqttgateway.com/index.php/parts)|
 |INA226|Current, Voltage|[parts list](https://compatible.openmqttgateway.com/index.php/parts)|
+|MQ2|Gas (flammable)|[parts list](https://compatible.openmqttgateway.com/index.php/parts)|
 |TEMT6000|Luminosity|[parts list](https://compatible.openmqttgateway.com/index.php/parts)|
 |TSL2561|Luminosity|[parts list](https://compatible.openmqttgateway.com/index.php/parts)|
 
@@ -29,6 +30,7 @@
 |HTU21 SCL|A5|D1|22|
 |INA226 SDA|A4|D2|21|
 |INA226 SCL|A5|D1|22|
+|MQ02 |A0 + D4|A0 + D4|A0 + D4|
 |TEMT6000 |A0|A0|A0|
 |TSL2561 SDA|A4|D2|21|
 |TSL2561 SCL|A5|D1|22|

environments.ini

@@ -99,6 +99,7 @@ build_flags =
   '-DZsensorHTU21="HTU21"'
   '-DZsensorAHTx0="AHTx0"'
   '-DZsensorTEMT6000="TEMT6000"'
+  '-DZsensorMQ2="MQ2"'
   '-DZsensorTSL2561="TSL2561"'
   '-DZsensorDHT="DHT"'
   '-DZsensorDS1820="DS1820"'
@@ -1106,6 +1107,7 @@ build_flags =
   ;'-DZsensorHTU21="HTU21"'
   '-DZsensorAHTx0="AHTx0"'
   '-DZsensorTEMT6000="TEMT6000"'
+  '-DZsensorMQ2="MQ2"'
   '-DZsensorTSL2561="TSL2561"'
   '-DZsensorDHT="DHT"'
   '-DZsensorDS1820="DS1820"'

main/User_config.h

@@ -326,6 +326,7 @@ int lowpowermode = DEFAULT_LOW_POWER_MODE;
 //#define ZsensorHCSR501 "HCSR501"  //ESP8266, Arduino, ESP32,  Sonoff RF Bridge
 //#define ZsensorADC     "ADC"      //ESP8266, Arduino, ESP32
 //#define ZsensorBH1750  "BH1750"   //ESP8266, Arduino, ESP32
+//#define ZsensorMQ2 "MQ2"  //ESP8266, Arduino, ESP32
 //#define ZsensorTEMT6000 "TEMT6000"  //ESP8266
 //#define ZsensorTSL2561 "TSL2561"  //ESP8266, Arduino, ESP32
 //#define ZsensorBME280  "BME280"   //ESP8266, Arduino, ESP32

main/ZmqttDiscovery.ino

@@ -768,6 +768,27 @@ void pubMqttDiscovery() {
   }
 #  endif
 
+#  ifdef ZsensorMQ2
+#    define MQ2parametersCount 2
+  Log.trace(F("MQ2Discovery" CR));
+  char* MQ2sensor[MQ2parametersCount][8] = {
+      {"sensor", "gas", "MQ2", "", jsonVal, "", "", "ppm"},
+      {"binary_sensor", "MQ2", "", "", jsonPresence, "true", "false", ""}
+      //component type,name,availability topic,device class,value template,payload on, payload off, unit of measurement
+  };
+
+  for (int i = 0; i < MQ2parametersCount; i++) {
+    createDiscovery(MQ2sensor[i][0],
+                    subjectMQ2toMQTT, MQ2sensor[i][1], (char*)getUniqueId(MQ2sensor[i][1], MQ2sensor[i][2]).c_str(),
+                    will_Topic, MQ2sensor[i][3], MQ2sensor[i][4],
+                    MQ2sensor[i][5], MQ2sensor[i][6], MQ2sensor[i][7],
+                    0, Gateway_AnnouncementMsg, will_Message, true, "",
+                    "", "", "", "", false, // device name, device manufacturer, device model, device ID, retain
+                    stateClassNone //State Class
+    );
+  }
+#  endif
+
 #  ifdef ZsensorTEMT6000
 #    define TEMT6000parametersCount 3
   Log.trace(F("TEMT6000Discovery" CR));

main/ZsensorMQ2.ino

@@ -0,0 +1,73 @@
+/*  
+  OpenMQTTGateway Addon  - ESP8266 or Arduino program for home automation 
+
+   Act as a wifi or ethernet gateway between your 433mhz/infrared IR signal  and a MQTT broker 
+   Send and receiving command by MQTT
+ 
+   This is the MQ2 GAS Sensor Addon based on modules with a MQ:
+   - Measures flammable gas
+   - Required Hardware Module: MQ2
+
+   Connection Scheme:
+   --------------------
+
+   MQ-2 -------> Arduino Uno ----------> ESP8266
+   ==============================================
+   Vcc ---------> 3.3V or 5V------------> 3.3V or 5V
+   GND ---------> GND ------------------> GND
+   A0 ----------> Pin A0 ---------------> A0
+   D0 ----------> Pin D4 ---------------> D4
+  
+    This file is part of OpenMQTTGateway.
+    
+    OpenMQTTGateway is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenMQTTGateway is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+#include "User_config.h"
+
+#ifdef ZsensorMQ2
+
+#  include "Wire.h"
+#  include "math.h"
+
+void setupZsensorMQ2() {
+  Log.notice(F("Setup MQ2 detection on pin: %d" CR), MQ2SENSORDETECTPIN);
+  pinMode(MQ2SENSORDETECTPIN, INPUT); // declare GPIOInput pin as input_pullup to prevent floating. Pin will be high when not connected to ground
+
+  Log.notice(F("Starting MQ2 calibration on pin: %d" CR), MQ2SENSORADCPIN);
+
+  //Simple calibrate
+  float sensorValue;
+  for (int x = 0; x < 1000; x++) {
+    analogRead(MQ2SENSORADCPIN);
+  }
+  delay(1000);
+
+  Log.trace(F("MQ2 Initialized." CR));
+}
+
+void MeasureGasMQ2() {
+  if (millis() > (timemq2 + TimeBetweenReadingmq2)) {
+    timemq2 = millis();
+
+    Log.trace(F("Creating MQ2 buffer" CR));
+    StaticJsonDocument<JSON_MSG_BUFFER> jsonBuffer;
+    JsonObject MQ2data = jsonBuffer.to<JsonObject>();
+
+    MQ2data["gas"] = analogRead(MQ2SENSORADCPIN);
+    MQ2data["detected"] = digitalRead(MQ2SENSORDETECTPIN) == HIGH ? "false" : "true";
+
+    pub(subjectMQ2toMQTT, MQ2data);
+  }
+}
+#endif

main/config_DHT.h

@@ -36,7 +36,9 @@ extern void DHTtoMQTT();
 /*-------------DHT SENSOR TYPE-------------*/
 //#define DHT_SENSOR_TYPE DHT11 //uncomment for DHT11 Sensor
 //#define DHT_SENSOR_TYPE DHT21 //uncomment for DHT21 Sensor
-#define DHT_SENSOR_TYPE DHT22 //uncomment for DHT22 Sensor (default for backwards compatibility)
+#ifndef DHT_SENSOR_TYPE
+#  define DHT_SENSOR_TYPE DHT22 //uncomment for DHT22 Sensor (default for backwards compatibility)
+#endif
 /*-------------------PIN DEFINITIONS----------------------*/
 #ifndef DHT_RECEIVER_GPIO
 #  if defined(ESP8266)

main/config_MQ2.h

@@ -0,0 +1,66 @@
+/*  
+  OpenMQTTGateway Addon  - ESP8266 or Arduino program for home automation 
+
+   Act as a wifi or ethernet gateway between your 433mhz/infrared IR signal  and a MQTT broker 
+   Send and receiving command by MQTT
+ 
+   This is the MQ2 GAS Sensor Addon based on modules with a MQ:
+   - Measures flammable gas
+   - Required Hardware Module: MQ2
+
+   Connection Scheme:
+   --------------------
+
+   MQ-2 -------> Arduino Uno ----------> ESP8266
+   ==============================================
+   Vcc ---------> 3.3V or 5V------------> 3.3V or 5V
+   GND ---------> GND ------------------> GND
+   A0 ----------> Pin A0 ---------------> A0
+   D0 ----------> Pin D4 ---------------> D4
+  
+    This file is part of OpenMQTTGateway.
+    
+    OpenMQTTGateway is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenMQTTGateway is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+#ifndef config_MQ2_h
+#define config_MQ2_h
+
+extern void setupZsensorMQ2();
+extern void MQ2toMQTT();
+
+#ifndef MQ2SENSORADCPIN
+#  ifdef ESP32
+#    define MQ2SENSORADCPIN 5 //MQ2 Gas sensor reading = ADC0
+#  else
+#    define MQ2SENSORADCPIN A0 //MQ2 Gas sensor reading = ADC0
+#  endif
+#endif
+
+#ifndef MQ2SENSORDETECTPIN
+#  ifdef ESP32
+#    define MQ2SENSORDETECTPIN 24 //MQ2 Gas sensor detected flag
+#  else
+#    define MQ2SENSORDETECTPIN D4 //MQ2 Gas sensor detected flag
+#  endif
+#endif
+
+#define TimeBetweenReadingmq2 10000
+/*----------------------------USER PARAMETERS-----------------------------*/
+/*-------------DEFINE YOUR MQTT PARAMETERS BELOW----------------*/
+#define subjectMQ2toMQTT "/GAStoMQTT/mq2"
+
+//Time used to wait for an interval before resending measured values
+unsigned long timemq2 = 0;
+
+#endif

main/main.ino

@@ -109,6 +109,9 @@ struct GfSun2000Data {};
 #ifdef ZsensorBH1750
 #  include "config_BH1750.h"
 #endif
+#ifdef ZsensorMQ2
+#  include "config_MQ2.h"
+#endif
 #ifdef ZsensorTEMT6000
 #  include "config_TEMT6000.h"
 #endif
@@ -879,6 +882,10 @@ void setup() {
   setupZsensorBH1750();
   modules.add(ZsensorBH1750);
 #endif
+#ifdef ZsensorMQ2
+  setupZsensorMQ2();
+  modules.add(ZsensorMQ2);
+#endif
 #ifdef ZsensorTEMT6000
   setupZsensorTEMT6000();
   modules.add(ZsensorTEMT6000);
@@ -1655,6 +1662,9 @@ void loop() {
 #ifdef ZsensorBH1750
       MeasureLightIntensity(); //Addon to measure Light Intensity with a BH1750
 #endif
+#ifdef ZsensorMQ2
+      MeasureGasMQ2();
+#endif
 #ifdef ZsensorTEMT6000
       MeasureLightIntensityTEMT6000();
 #endif