futurlec MQ131 (ozone sensor) MQ135 (air quality) CO2SENSOR

Hi, Does anyone have sample code on how to interface the Futurlec MQ131 (ozone sensor), MQ135 (air quality) and CO2SENSOR with arduino? Is there any specific library file required? Sorry, newbie and can't seem to find any demo code on how to use these sensors - or how to connect them.. Thanks!

Hi Janey,

Do you have a link to a datasheet?


thanks rob!

datasheets are here -




Seen the CO2 sensor before, can't find the code sorry. I recall you must neat up the sensor for some time and then measure how long it takes before some line got below a certain threshold.

something like this one, - http://entreprene.us/2010/12/14/arduino-co2-sensor-processing-panel-display/

Hi, This is my first time in the forum. I'm working with the same IC (mq-135). And I found in Wiring webpage a pin-conection example. I hope this link help to you. Now I'm trying to understand the info that I get in my Serial Monitor. Some body know how understand the data?,


This is the link with the pin conection

Some body know how understand the data?,

Sorry I cannot see : 1) your code 2) the output 3) the conditions of the measurement 4) the wiring

so the answer is Yes, there is somebody who understands the data, but unless you provide the above they are hard to find ;)


I am also fighting with those sensors. For the moment, i can send you the code that i use, and a windows program that i am writing in order to calibrate and use this senor. It is a very very first draft, but it works (tested on windows xp). As soon as i will have a better version i will post them here.

The arduino code is very very simple:

void setup()

void loop()
  Serial.println(analogRead(0),DEC);  // prints the value read

The attached software work with a serial of 115200 bauds rate. So, do not change this on the arduino code.

Upps!, i can´t upload the file because is no heavy. I will upload to my server and edit this post to show the download link in few minutes...

In order to undertand the results, here you have a previos discussion in this forum: http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1251383821/all


Ok, here is the link to download the exe file for windows (tested on windowsxp) to read and plot the data from arduino following the code above. The software is still not the first verion, but it runs, and could help to you and others to see and plot data from one sensor wired to arduino. http://dl.dropbox.com/u/5093076/Arduino_Forum/ArduinoDataViewer.exe Enjoy!

The wiring of the MQ135 that i use is this: http://wiring.org.co/learning/basics/airqualitymq135.html

Edited II:

And here you have an instructable that use MQ131 sensor with arduino. It includes an arduino sketch. http://www.instructables.com/id/Environmental-Mushroom-Control-Arduino-Powered

I hope it could helps you