Chemical warfare detection was never supposed to be a hobbyist project. Yet here we are: Air Quality Guardian by [debdoot], the self-proclaimed world’s first open source chemical threat detection system, packs lab-grade sensing into an ESP32-based build for less than $100. Compare that with $10,000+ black-box hardware and you see why this is worth trying at home.
It’s nothing like your air monitor from IKEA. Unlike those, or the usual indoor monitors, this device goes full counter-surveillance. It sniffs for organophosphates, carbamates, even stealth low-VOC agents designed to trick consumer sensors. It flags when incense or frying oil is used to mask something nastier. It does so by analysing raw gas sensor resistance – ohm-level data most devices throw away – combined with temporal spikes, humidity correlations, and a database of 35+ signatures.
This technology – once only available in expensive military labs – can be useful in many situations: journalists or whistleblowers can record signs of chemical harassment, safehouses can notice when their air changes in suspicious ways, and researchers can test strange environmental events. Of course, you must take care with calibration, and sometimes the system may give a false alarm. Still, just having such a detector visible already makes attacks less likely.
Featured Image by Arjun Lama on Unsplash
I truly admire the self-confidence of the person who wrote the readme, boldly explaining how this arduino + 8€ COTS sensor combined with ~900 lines of C++ is better than professional chemical warfare detection systems.
I’d also be interested to hear how they think they developed a system for detecting nerve gas/Sarin, and how they think they tested it to ensure the code is working, bearing in mind that the manual for the BME688/AI-studio says it has to be taught what signal a chemical will generate.
Even worse, they likely made an LLM like ChatGPT write it! The emojis are a dead giveaway
The real information is here is:
PMS7003 particulate sensor ( plantower.com/en/products_33/76.html )
BME688 gas sensor ( http://www.bosch-sensortec.com/products/environmental-sensors/gas-sensors/bme688/ )
How does this compare to the SEN54 ( sensirion.com/products/catalog/SEN54 ) used in the IKEA product? dunno.
The SEN54 is a very simple sensor and can only give a simple VOC score. The Bosch sensor can also do VSC’s that the SEN54 doesn’t appear to be able to do. It seems to me that the Bosch BME688 is a much better sensor. For example, the Bosch BME688 is capable of detecting H2S that the SEN54 is not capable of doing that. H2S would be the primary thing I would test.
Sorry, but this whole thing stinks. (Hah. See what I did there?). My understand of these sensors is limited, so please correct me if I’m wrong.
The sensitivity of the detector seems to be controlled by the temperature of the sensing element. Higher temperature = higher sensitivity. However, from what I can gather from the datasheet, it simply detects ANY VOCs which are reactive enough to do stuff to the sensor. I fail to see how on earth you can get a “signature” which allows you to identify a particular compound. Compare that with proper detectors which have a detection method that is closely matched to the compound in question – e.g. an enzyme or bacteria which will only react with an organophosphate and nothing else.
Unless you have access to the compounds in question to actually test the sensor, I fail to see how you could determine the “signatures” for each or have any faith in what the sensor is saying.
Next, how the project is presented. Reading the github page, it sounds like the sort of sensationalised guff that an AI would generate. Sure enough, pasting it into 4 different AI text checkers, they ALL said it was 100% AI-generated.
The user is “dirtysalsa” based in Kolkata and they have a twitter account at https://x.com/dirtysalsa and a website at https://www.dirtysalsa.com/ (seems to be how-to videos on Salsa dancing). Their twitter feed has a whole conspiracy theory feel to it – numerous sensational posts about “heavy metal attacks” or “neurotoxin” attacks, tagging the UN, Kolkata police. Believes someone upstairs is spreading poisonous gas etc. etc. and that’s why they built this sensor.
Generally, Hackaday, please have a good look at who’s behind this.
Yeah, I’d never head of “chemical harassment” before but it made my BS detector ping. Googled a bit, and found only people who believe that the smell of fabric softener in a laundromat is an attack targeted at them personally, and that other people’s presence in public is specifically designed to inconvenience them.
Well yes – BME688 can’t detect CO2 – it is just estimate based on the amount of VOCs and an assumption that they are produced by humans breathing. This is just BS. So the only thing they can measure is VOC concentration (badly, the sensor is good for rough estimate and thats that) and dust. The rest is just AI generated slop and conspiracy theories.
Please stop this – it is like publishing articles about new devices to measure flatness of earth to prove that the earth is flat or something.
Red flags:
1) Github description is likely AI-generated (I pasted it into 4 different checkers and they all said 100% likelyhood)
2) User’s twitter account (https://x.com/dirtysalsa) has a total conspiracy theory flavor to it. Believes someone upstairs is poisoning them with gas so they built this detector to check it. I kid you not. For example: https://x.com/dirtysalsa/status/1964072290540216633
Why do paranoid people have the most entertaining and humorous Twitter accounts
Another red flag: the “Project structure” part of the README lists a very impressive tree of files…most of which don’t exist.
anyone who actually worke din the field with RMOX sensors will tell you: this will onyl work with oen sensor, as the sensor to sensor variation is very very wide. Also age will quickly alter resistance response.
Mountains of AI generated fluff in the readme, no prototype, no demonstration. Why would you post this?
From a superficial “sniff test”: Heidi Ulrich last posted an “article” 20 days ago….
Okay, maybe just on holiday but I wanted to throw a sniff test in here. ;-)