Simple Gadgeteer Gas Sensor module demo which uploads 3 gas sensor readings, 2 temperature readings, pressure and humidity readings to COSM using a Cerberus and ENC28 network module.
My COSM URL for this project is at https://cosm.com/feeds/83667 but this of course is for only as long as I’m running the demo. Once my other gas sensor components arrive I’ll be using a couple of these setups to test different sensors including:
MQ-2 Flammable Gas & Smoke Sensor
MQ-4 Methane CNG Gas Sensor
MQ-5 LPG, Natural gas, Coal gas Sensor
MQ-6 LPG Propane Gas Sensor
MQ-7 Carbon Monoxide Sensor
MQ-8 Hydrogen Gas Sensor
MQ-9 CO and Combustible Gas Sensor
MQ-131 Ozone Gas Sensor
MQ-135 Air Quality Sensor
MQ-136 H2S Gas Sensor
MQ-137 Ammonia Gas Sensor
MQ-138 Formaldehyde Gas Sensor
MQ-139 Freon Gas Sensor
Calibration of these sensors is rather difficult as it implies either you have a known sample of gas, or your have a calibrated device to compare to, or both. So its best to use these as a relative measurement, so for example the measurements shown would be a baseline of 0 Alcohol as there isn’t any alcohol around (ie clean air). Currently I’m more interested right now in burning in the sensors (I bought 9 sensors so lucky me as I now have 9 MQ-3 sensors but I’m really waiting for some other sensors to be delivered, but they don’t ship as fast as GHI does ), and will do some follow up experiments later with those sensors.
My interest in these sensors is mostly comparative (meaning relative comparisons between different locations), and relative over time to detect leak and operational problems, so knowing exact values isn’t that important, only how much it differs (hence why just running base cases over different temps/humidities is of interest).
Certainly the sensor manufacture could give better specs and test data, but its a < $5 sensor so expecting to build a legal grade breathalyser is somewhat over optimistic (a number of folks built drinking game devices with these but I don’t want to endose any of those of course)
Question, what is the best way to post a ThingSpeak ( https://www.thingspeak.com )version of this project? Should I post it as another CodeShare project?
), and will do some follow up experiments later with those sensors.