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  3. Air Quality Sensor

Air Quality Sensor

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calibrationaqigas sensorhchoair quality
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  • epierreE epierre

    @alexsh1 well any I would think for they are similar technology

    alexsh1A Offline
    alexsh1A Offline
    alexsh1
    wrote on last edited by
    #227

    @epierre What about MICS-4514 or MICS-5524?

    I am thinking ordering this board:
    https://sgx.cdistore.com/ProductDetail/MICSVZ86F-SGX-Sensortech-Limited-formerly-e2v/556306/#.V2Bw7jVUmec

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    • Tore André RosanderT Offline
      Tore André RosanderT Offline
      Tore André Rosander
      wrote on last edited by Tore André Rosander
      #228

      How do i get the Airquality sensor to show in domoticz? I use the AirQuality example from the library and MQ2.
      I can see that it works in the serial, and it shows as a node under the mysensors hardware, but nothing in log or the device list when i expose it for gas.

      0_1466081228162_upload-0f9ebe47-10d5-446c-a3bd-24c1649c94c1

      epierreE 1 Reply Last reply
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      • Tore André RosanderT Tore André Rosander

        How do i get the Airquality sensor to show in domoticz? I use the AirQuality example from the library and MQ2.
        I can see that it works in the serial, and it shows as a node under the mysensors hardware, but nothing in log or the device list when i expose it for gas.

        0_1466081228162_upload-0f9ebe47-10d5-446c-a3bd-24c1649c94c1

        epierreE Offline
        epierreE Offline
        epierre
        Hero Member
        wrote on last edited by
        #229

        @Tore-André-Rosander said:

        ut nothing in log or the device list when i expose it for gas.

        huh you're on which version of mysensors ? have you tried the console (in arduino programmer) to see if there are some readings or a good wiring ?

        z-wave - Vera -> Domoticz
        rfx - Domoticz <- MyDomoAtHome <- Imperihome
        mysensors -> mysensors-gw -> Domoticz

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        • Tore André RosanderT Offline
          Tore André RosanderT Offline
          Tore André Rosander
          wrote on last edited by Tore André Rosander
          #230

          @epierre Hi! The dev branch (v 2) and the raspberry pi gateway (nrf24 directly connected to RPi GPIO). This is what i get in the serial console when i test with gas from a lighter:

          Starting sensor (RNNNA-, 2.0.0-beta)
          Radio init successful.
          find parent
          send: 255-255-255-255 s=255,c=3,t=7,pt=0,l=0,sg=0,st=bc:
          find parent
          send: 255-255-255-255 s=255,c=3,t=7,pt=0,l=0,sg=0,st=bc:
          read: 0-0-255 s=255,c=3,t=8,pt=1,l=1,sg=0:0
          parent=0, d=1
          req id
          send: 255-255-0-0 s=255,c=3,t=3,pt=0,l=0,sg=0,st=ok:
          req id
          send: 255-255-0-0 s=255,c=3,t=3,pt=0,l=0,sg=0,st=ok:
          read: 0-0-255 s=255,c=3,t=4,pt=0,l=2,sg=0:5
          
          send: 5-5-0-0 s=255,c=3,t=15,pt=0,l=2,sg=0,st=ok:
          send: 5-5-0-0 s=255,c=0,t=17,pt=0,l=10,sg=0,st=ok:2.0.0-beta
          send: 5-5-0-0 s=255,c=3,t=6,pt=1,l=1,sg=0,st=fail:0
          id=5
          Init complete, id=5, parent=0, distance=1
          0
          LPG:0ppm    CO:0ppm    SMOKE:0ppm
          0
          LPG:8ppm    CO:47ppm    SMOKE:18ppm
          send: 5-5-0-0 s=0,c=1,t=37,pt=2,l=2,sg=0,st=ok:95
          0
          LPG:0ppm    CO:0ppm    SMOKE:0ppm
          send: 5-5-0-0 s=0,c=1,t=37,pt=2,l=2,sg=0,st=ok:0```
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          • epierreE Offline
            epierreE Offline
            epierre
            Hero Member
            wrote on last edited by
            #231

            @Tore-André-Rosander said:

            t=37

            I don't know, would it be possible to have someone knowing the difference of the gateway with domoticz for 2.0 ? here it seems correct to me, some value are well seend from the sensor, so it is between the gateway and domoticz for me.

            z-wave - Vera -> Domoticz
            rfx - Domoticz <- MyDomoAtHome <- Imperihome
            mysensors -> mysensors-gw -> Domoticz

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            • tuimansoT Offline
              tuimansoT Offline
              tuimanso
              wrote on last edited by
              #232

              @epierre I am attempting to apply this code to work with the MQ-8. I am trying to get rid of all of the radio and gw stuff that is in the code. Do you have anything that just calibrates the sensor and reads out the value without of all these other libraries?

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              • tuimansoT Offline
                tuimansoT Offline
                tuimanso
                wrote on last edited by
                #233

                @epierre Also, what is the purpose of #define MQ135_MAXRSRO 2.428 //for CO2
                #define MQ135_MINRSRO? I don't see them being referenced after they're defined?

                epierreE 1 Reply Last reply
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                • tuimansoT tuimanso

                  @epierre Also, what is the purpose of #define MQ135_MAXRSRO 2.428 //for CO2
                  #define MQ135_MINRSRO? I don't see them being referenced after they're defined?

                  epierreE Offline
                  epierreE Offline
                  epierre
                  Hero Member
                  wrote on last edited by
                  #234

                  @tuimanso said:

                  @epierre Also, what is the purpose of #define MQ135_MAXRSRO 2.428 //for CO2
                  #define MQ135_MINRSRO? I don't see them being referenced after they're defined?

                  Datasheet defines min and max values they should guarantee, this is an application of it.

                  if(validinterval<MQ135_MAXRSRO && validinterval>MQ135_MINRSRO) {
                  

                  z-wave - Vera -&gt; Domoticz
                  rfx - Domoticz &lt;- MyDomoAtHome &lt;- Imperihome
                  mysensors -&gt; mysensors-gw -&gt; Domoticz

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                  • tuimansoT Offline
                    tuimansoT Offline
                    tuimanso
                    wrote on last edited by
                    #235

                    Your previous message

                    Hello,

                    I have a question about the MQ-8 sensor module . The potentiometer that is soldered onto the board, is it to control the sensitivity of the LED light or for the sensor itself? According to the datasheet for the sensor, the RL (load resistance) for the sensor should be at minimum 10k Ohm, yet I only see an SMD 102 resistor on the board, which is a 1K Ohm resistor. I have used a multimeter to connect the 5V pin and the AOUT pin, and I get precisely a measurement of about 1K Ohm... Does that mean that I should connect a load resistor to this?

                    This value seems very important since it is referenced in the code, the RL is part of the calculations, yet it is already pre-written 10K ohms...

                    Please Clarify
                    Thanks

                    ysinhY 1 Reply Last reply
                    0
                    • AtmosChemeA Offline
                      AtmosChemeA Offline
                      AtmosCheme
                      wrote on last edited by
                      #236

                      Hello everyone,

                      I have a few of these sensors, but lately I have been concentrating on a MQ131 ozone sensor module from SainSmart. I am building an array utilizing MQ gas sensors and an Arduino that can be attached to a drone to measure vertical concnentration profiles of ground level ozone.

                      I am using an ozone generator and a 2B Technologies Ozone Monitor for the calibration of the sensor.

                      I have done the 24 hour burn in period on my sensors.
                      I have warmed them up to get steady values on my serial monitor.

                      The problem that I am having is that I am creating nearly 20,000 ppb O3 and the analog output is only around 25 to 30 units. It works out to around 922 ppb per unit.

                      Example before ozone is added the sensor reading is steady at 41. After raising the concentration of O3 to 18,727.5 ppb the reading drops to around 17-18.

                      Recently I have added a 22,000 ohm resistor in series with the analog output so that my readings start out at 971. But I am still only dropping around 20 units to 951 when ozone levels rise to nearly 20,000 ppb.

                      My question is how do I use a larger range of the units. There are 1023 possible values and I would like to see my reading drop from 971 to maybe the 200 area so that I am using more of the range. I would like each unit to be worth about 0.5 ppb. Ambient outdoor concentrations very rarely go higher than maybe 150 ppb so with the setup I have that would not even register on the serial output.

                      Thank you in advance for any help.

                      epierreE 1 Reply Last reply
                      1
                      • AtmosChemeA AtmosCheme

                        Hello everyone,

                        I have a few of these sensors, but lately I have been concentrating on a MQ131 ozone sensor module from SainSmart. I am building an array utilizing MQ gas sensors and an Arduino that can be attached to a drone to measure vertical concnentration profiles of ground level ozone.

                        I am using an ozone generator and a 2B Technologies Ozone Monitor for the calibration of the sensor.

                        I have done the 24 hour burn in period on my sensors.
                        I have warmed them up to get steady values on my serial monitor.

                        The problem that I am having is that I am creating nearly 20,000 ppb O3 and the analog output is only around 25 to 30 units. It works out to around 922 ppb per unit.

                        Example before ozone is added the sensor reading is steady at 41. After raising the concentration of O3 to 18,727.5 ppb the reading drops to around 17-18.

                        Recently I have added a 22,000 ohm resistor in series with the analog output so that my readings start out at 971. But I am still only dropping around 20 units to 951 when ozone levels rise to nearly 20,000 ppb.

                        My question is how do I use a larger range of the units. There are 1023 possible values and I would like to see my reading drop from 971 to maybe the 200 area so that I am using more of the range. I would like each unit to be worth about 0.5 ppb. Ambient outdoor concentrations very rarely go higher than maybe 150 ppb so with the setup I have that would not even register on the serial output.

                        Thank you in advance for any help.

                        epierreE Offline
                        epierreE Offline
                        epierre
                        Hero Member
                        wrote on last edited by
                        #237

                        @AtmosCheme the datasheet gives the MQ131from 1 to 1000 ppb, so you reach the limit obviously

                        http://eph.ccs.miami.edu/precise/GasSensorSpecs/Ozone.pdf

                        z-wave - Vera -&gt; Domoticz
                        rfx - Domoticz &lt;- MyDomoAtHome &lt;- Imperihome
                        mysensors -&gt; mysensors-gw -&gt; Domoticz

                        AtmosChemeA 1 Reply Last reply
                        0
                        • epierreE epierre

                          @AtmosCheme the datasheet gives the MQ131from 1 to 1000 ppb, so you reach the limit obviously

                          http://eph.ccs.miami.edu/precise/GasSensorSpecs/Ozone.pdf

                          AtmosChemeA Offline
                          AtmosChemeA Offline
                          AtmosCheme
                          wrote on last edited by
                          #238

                          @epierre

                          Thank you for the reply epierre.

                          I was going off of the SainSmart website that says the range for their module is 10 ppb to 200 ppm. That would cover 10 ppb to 200,000 ppb.

                          http://www.sainsmart.com/sensors/eco/sainsmart-mq131-gas-sensor-ozone-module-for-arduino-uno-mega2560-r3-raspberry-pi.html

                          The values keep dropping down as more and more ozone is added, I'm not thinking it is a problem with range as much as a problem with resolution. I have gone as high as around 50,000 ppb and continue to get response from the sensor.

                          Ive thought of using mapping functions in my code as well as resolution functions. But I just wasn't sure if there was a component I could add to the circuit to improve resolution.

                          In my latest sketch I have used a calibration code that analog reads the sensor for 6 minutes, and then remaps the min and max values observed during that time. I though this would get a broader range of values. The problem is that the longer the sensor is on it becomes stable so the min and max values become the same and there is nothing to map. So the longer it runs the smaller the range of values in the serial monitor.

                          epierreE 1 Reply Last reply
                          0
                          • AtmosChemeA AtmosCheme

                            @epierre

                            Thank you for the reply epierre.

                            I was going off of the SainSmart website that says the range for their module is 10 ppb to 200 ppm. That would cover 10 ppb to 200,000 ppb.

                            http://www.sainsmart.com/sensors/eco/sainsmart-mq131-gas-sensor-ozone-module-for-arduino-uno-mega2560-r3-raspberry-pi.html

                            The values keep dropping down as more and more ozone is added, I'm not thinking it is a problem with range as much as a problem with resolution. I have gone as high as around 50,000 ppb and continue to get response from the sensor.

                            Ive thought of using mapping functions in my code as well as resolution functions. But I just wasn't sure if there was a component I could add to the circuit to improve resolution.

                            In my latest sketch I have used a calibration code that analog reads the sensor for 6 minutes, and then remaps the min and max values observed during that time. I though this would get a broader range of values. The problem is that the longer the sensor is on it becomes stable so the min and max values become the same and there is nothing to map. So the longer it runs the smaller the range of values in the serial monitor.

                            epierreE Offline
                            epierreE Offline
                            epierre
                            Hero Member
                            wrote on last edited by
                            #239

                            @AtmosCheme said:

                            I was going off of the SainSmart website that says the range for their module is 10 ppb to 200 ppm. That would cover 10 ppb to 200,000 ppb.

                            check their datasheet (or ask for it !)

                            The values keep dropping down as more and more ozone is added, I'm not thinking it is a problem with range as much as a problem with resolution. I have gone as high as around 50,000 ppb and continue to get response from the sensor.

                            yes it should be possible but you don't know from the datasheet the value. On a power regression you make an estimation with error, but that may change outside of know datapoints.

                            Ive thought of using mapping functions in my code as well as resolution functions. But I just wasn't sure if there was a component I could add to the circuit to improve resolution.

                            some as the Particle Photon has a better ADC that goes up to 4096

                            z-wave - Vera -&gt; Domoticz
                            rfx - Domoticz &lt;- MyDomoAtHome &lt;- Imperihome
                            mysensors -&gt; mysensors-gw -&gt; Domoticz

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                            • jnewton957J Offline
                              jnewton957J Offline
                              jnewton957
                              wrote on last edited by
                              #240

                              Hi,

                              I just try to connect 7 sensors to an nano.
                              MQ-2, MQ-3, MQ-4,MQ-6, MQ-7,MQ-9, MQ-135

                              With sketch form robosensor https://forum.mysensors.org/topic/1595/mq2-sensor-w-airquality-sketch/2

                              I get data like MQ-7:1020 ,MQ135: 294, MQ-2:191

                              So it looks really good.
                              As i would like to have also the correct names an value names of the sensor and a correct calibration I think I should use a sketch like AirQuality-Multiple_Gas_Sensor1_4.ino
                              But I only see 3 of my 7 sensors in this sketch.

                              What would be a good sketch for my 7 sensors ??

                              Thanks
                              Jorg

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                              • walk_portoW Offline
                                walk_portoW Offline
                                walk_porto
                                wrote on last edited by
                                #241

                                Hello everybody,

                                I am working with an Arduino Uno and a MQ135 module arduino : http://www.sainsmart.com/sainsmart-mq135-sensor-air-quality-sensor-hazardous-gas-detection-module-arduino.html

                                I can get back data from this sensor, I got 100 ppm when I launched serial terminal after compiling and uploading this code below.

                                int sensorValue;
                                
                                void setup()
                                {
                                  Serial.begin(9600);      // sets the serial port to 9600
                                }
                                
                                void loop()
                                {
                                  sensorValue = analogRead(0);       // read analog input pin 0
                                  Serial.println(sensorValue, DEC);  // prints the value read
                                  delay(100);                        // wait 100ms for next reading
                                }
                                

                                But, I would like to get back data from gases like NH3, NOx, alcohol, benzene, smoke and CO2 . I read a lot of topics and the datasheets of the sensor but I don't see how to do.

                                If someone could help me, it will be great.

                                Thanks.

                                AtmosChemeA 1 Reply Last reply
                                0
                                • walk_portoW walk_porto

                                  Hello everybody,

                                  I am working with an Arduino Uno and a MQ135 module arduino : http://www.sainsmart.com/sainsmart-mq135-sensor-air-quality-sensor-hazardous-gas-detection-module-arduino.html

                                  I can get back data from this sensor, I got 100 ppm when I launched serial terminal after compiling and uploading this code below.

                                  int sensorValue;
                                  
                                  void setup()
                                  {
                                    Serial.begin(9600);      // sets the serial port to 9600
                                  }
                                  
                                  void loop()
                                  {
                                    sensorValue = analogRead(0);       // read analog input pin 0
                                    Serial.println(sensorValue, DEC);  // prints the value read
                                    delay(100);                        // wait 100ms for next reading
                                  }
                                  

                                  But, I would like to get back data from gases like NH3, NOx, alcohol, benzene, smoke and CO2 . I read a lot of topics and the datasheets of the sensor but I don't see how to do.

                                  If someone could help me, it will be great.

                                  Thanks.

                                  AtmosChemeA Offline
                                  AtmosChemeA Offline
                                  AtmosCheme
                                  wrote on last edited by
                                  #242

                                  @walk_porto

                                  I think that the only way you are going to be able to distinguish between different gases is to have a known concentration of that gas and adjust load resistance. This sensor will detect all of these gase because of cross sensitivity to the gases mentioned in the filament. You can not use just one MQ135 sensor and get readings for all of the gases.

                                  1 Reply Last reply
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                                  • Thanh-VietT Offline
                                    Thanh-VietT Offline
                                    Thanh-Viet
                                    wrote on last edited by
                                    #243

                                    Hi Guys,

                                    Nice work. I'm based in Hong Kong, and what matters to us is PM2.5, NO2 and Ozone (and indoor CO2/VOC).

                                    Have you guys checked the laser based particle sensors like the Plantower G1-G3-G5, Innovafitness SDS011/021 ?
                                    http://aqicn.org/sensor

                                    alexsh1A 1 Reply Last reply
                                    0
                                    • Thanh-VietT Thanh-Viet

                                      Hi Guys,

                                      Nice work. I'm based in Hong Kong, and what matters to us is PM2.5, NO2 and Ozone (and indoor CO2/VOC).

                                      Have you guys checked the laser based particle sensors like the Plantower G1-G3-G5, Innovafitness SDS011/021 ?
                                      http://aqicn.org/sensor

                                      alexsh1A Offline
                                      alexsh1A Offline
                                      alexsh1
                                      wrote on last edited by
                                      #244

                                      @Thanh-Viet Hello. Yes, I have Plantower G3 on order from Aliexpress and won't be able to test it before September. I think adopting it for MySensors is going to be easy

                                      1 Reply Last reply
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                                      • paqorP Offline
                                        paqorP Offline
                                        paqor
                                        wrote on last edited by
                                        #245

                                        Hello, there are statements if the values increase the MQ135 when a room ventilated, without people and is furnished? I I have several rooms here an increase over time. Perhaps this is also by the increase in temperature, sunlight or gases from the furniture. I have not found any literature on this. Is this behavior with other users as well?

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                                        • paqorP Offline
                                          paqorP Offline
                                          paqor
                                          wrote on last edited by
                                          #246

                                          Has the type of installation (horizontal or vertical) have an impact on the values of MQ135? I have found no photos of built-in sensors already exist in the data sheet a statement.

                                          alexsh1A 1 Reply Last reply
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