Smart phones have many sensor but not enough for me. So I attached a bunch of sensors to an arduino mega. Specifically the MQ2 through 9 set plus BME680, DHT22 and CCS811. Those are all gas and weather sensors. Specifically temperature, humidity, pressure, several combinations of TVOC, eCO2.
MQ-2 Methane, Butane, LPG, smoke 5V
MQ-3 Alcohol, Ethanol, smoke 5V
MQ-4 Methane, CNG Gas 5V
MQ-5 Natural gas, LPG 5V
MQ-6 LPG, butane gas 5V
MQ-7 Carbon Monoxide Alternating 5V and 1.4V
MQ-8 Hydrogen Gas 5V
MQ-9 Carbon Monoxide, flammable gasses. Alternating 5V and 1.4V
MQ135 Air Quality (Benzene, Alcohol, smoke) 5V.
The MQ set is just 15 usd. That is why I bought it. The MEGA easily handles computation and the SD card takes days to fill but the entire system is a big energy hog. Some of these sensors are redundant and unnecessary. Which sensors should I remove and which should I add? For example how about a Geiger counter? I am asking now for design and month long shipping from china.
The electric nose uses 5v * .8A = 4 Watt /hour and the bigger KMASHI only has 55Wh. So 13 hours. Charging takes longer. The weather sensors are much nicer and a 37Wh battery lasts days. Bit of a problem this.
TI sensortag can do weather stuff for cheaper. But in the mean time burning paper, gas lighter fluid, burning smoking paper, then the big spike is acetone and the later few bumps are WD-40.
Thank you for your interest but I a m afraid I did not understand much of what you said. Also the project is frozen now and I do not expect to get back to it for years.