Matadormac:
Good day all.
I am a first time Arduino user/builder (or will be). I wish to monitor the level (up to 100%) of CO2 along with RH and temp inside a fumigation bubble tent for use within museums. We have been using such a tent for many years but the monitoring within the tent has been for O2 only and requires a wall piercing for the probe connection. I wish to upgrade and change that.
I have found the sensor for the CO2, one of the COZIR sensors, likely the wide range one. It may or may not be able to also provide RH and Temp data. In the event that it does not, then I will have to add an RH/Temp sensor.
There needs to be data-logging capability lasting at the minimum for 3 weeks duration. An SD card would be fine.
But, I need to be able to connect wirelessly in some manner to monitor real time current data and to retrieve data from the SD card (without deleting that data).
Also, this would need to be a self contained apparatus for the duration of the fumigation run (normally 2 to 3 weeks).
Ideally I would be able to have three sets of sensors. One placed high in the bubble tent, one at mid-level and one near the bottom of the tent. This would be to track stratification due to density sorting by the gas environment.
I think these are my requirements.
I would like your thoughts on the feasibility of this project. But also I would very much like some help in getting started with choosing what Arduino, shields, etc. that I should begin pulling together. A good start at a basic shopping list would be ideal.
I look forward to your thoughts and advice.
Regards
Matadormac
Indeed, this sounds QUITE feasible. I don't know about the CO2 sensor. I'll leave that to you.
There are off-the-shelf serial interface temp/humidity sensors you can buy. SparkFun sells a couple: Check out this link: https://www.sparkfun.com/products/10167
There is another one that has .5 degree (F) precision.
You need to map out the parameters of your problem. Is there AC power inside the space that will be enclosed by the tent(s)? If so, you won't need to worry about batteries.
Bluetooth Low Energy is very low power, and has a range of about 60 meters in ideal conditions, but inside a building is not ideal conditions.
How far is the distance between the location where you need the different sensors, and is there line of site between them? Will they all be in the same tent? You could lower the cost and power requirements if you could run all 3 sets of sensors from the same Ardudino, but then you would need to run long wires, and might need to adjust for the additional resistance from the longer wires.
You might need to run some tests to see if you can get BLE signals between your Arduino module(s) and your PC.
I would suggest researching a Bluetooth shield and which Arduinos it works with. Then buy an Arduino and the BLE shield, write a test program that sends data over BLE, put it in the target locations in the museum, put the PC in the target receiving location, and make sure you can receive the BLE signals.
You can estimate the amount of power needed by adding up the current requirements of the different devices (Arduino, BLE shield, sensor modules, etc.) Batteries are rated in amp-hours. Add up your current requirements, multiply by the number of hours you need the device to run, and get a battery that provides 20% to 50% more than that so you have a margin of safety. Measuring the actual current used would be more accurate, but probably isn't required.
All the devices you are talking about are very low power devices, so you should be able to run them for your 3 week duration using a battery. At the worst you could probably use a car battery, which provides gobs of power and is designed for long shelf-life, but that will probably be overkill. I expect a smaller 6 volt sealed lead-acid battery like those used for alarm systems would provide plenty of power
