Collecting Data from O2, °C, CO, CO2 and humidity sensors

Other Hardware Sensors
21

My sensors are as follows:

O2
CO²
Humidity and Temperature
CO

The ESP32 will be used as follows:

1.ESP - O2 Sensor
2.ESP - O2 Sensor
3.ESP - O2 Sensor, CO, Hum. & Temp.
4.ESP - O2 Sensor, CO, Hum. & Temp.
5.ESP - O2 Sensor, CO², Hum. & Temp.
6.ESP - O2 Sensor, CO², Hum. & Temp.

In theory it would be possible to half the amount of ESP needed, as some of them are not that far from each other.

Do I need anything else than a ESP for the SENSORs to connect with eacht other?

I would go now for this ESP'S or can anyone recommend me something more usefull esp?

As Mainboard I would use this arduino to make sure I will have in any case enought Digital I/O's

Please let me know if there is anything else I need for it.

22

You are buying sensors that cost a fortune, why would you want to half $5 Esp32 count and get into serious troubles with interferences etc. Serial/I2C wiring should be ideally <30cm.

So max current draw is O 14mA, CO2 42ma, TH 2mA, CO 5mA.
<60mA/ Esp. OK.

What is that Mainboard doing?
Esp32-network doesn't need it.

23

We need to controll some other things while the sensors are reading out the environment inside the chamber. For example, we will fill the chamber with Nitrogen to a specific O2-Level until a Valve needs to be closed. So in my opinion we need have Digital I/O. Next to that I would like to measure some Currents of machines connected to the chamber. That I think I need an arduino board also. The Arduino should be like a "PC" that collects all data and makes a .csv file for example on my server.

Let me know if it is clear

24

I completely agree with user kmin, please use the same ESP32 board for the "main" board.

There is a ESP32-C3. It is a small and cheaper board.
LOLIN/Wemos has these boards: https://www.wemos.cc/en/latest/c3/c3_mini.html

Wikipedia has a good list with the variants: https://en.wikipedia.org/wiki/ESP32#ESP32-xx_family

The "main" board should be simple and run software.
If you need many inputs and outputs near the "main" board, then you could make another module (with the same ESP32 board as the others) that has extra hardware for extra inputs and outputs: https://www.adafruit.com/product/5346
That is much more modular and easier.

25

Thank you, @Koepel, for the explanation.

I’m going to get 7 ESP32-C3 boards with MicroUSB connectors—6 for the sensors, with a maximum of 3 sensors connected to each, and 1 for the "main" board.

How does the coding work on the ESP32? Is it comparable to using the Arduino IDE?

Do I need anything else besides the 7 boards and the sensors? For instance, connectors for the sensors or any other components?

Do I need anything else then 7 boards and the sensors for it? Like connectors for the sensors or anything?

26

The ESP32 (and variants) run Arduino code, but there are also extra functions and special libraries. That website I wrote about has many tutorials: https://randomnerdtutorials.com/

It is possible to use OTA (Over The Air) uploading of a sketch.

I don't know about connectors.
Do you know how to solder ?
Please don't use a breadboard for a final project. Those are not reliable because they might have bad contacts.

27

Yes I know how to solder. I got everything here for it.
What you mean with breadboard for final project?

I mean there are three connectors from the sensor, that needs to be wired with the ESP i think?! or are there shields or something available?

28

Breadboards can have bad contacts and jumper wires can be broken.
You can use them for a test (if you have to), but they are not suitable for an actually working project.

You could use prototype board. Solder a connector on it for the sensor and solder wires to the ESP32 board.

The sensors seem to have Molex 2695 connectors. Sometimes a webshop has the pcb connectors or else you can buy everything a Mouser.com.
Mouser is a well-known distributor of genuine parts.

If Mouser sells the DS18B20 for 5 dollars and AliExpress sells the DS18B20 for 1 dollar, then that means that Mouse is asking a normal reasonable price and AliExpress is selling a counterfeit sensor.

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29

Ok. But what exactly is meant by Breadboard? ESP 32?

30

Breadboard: https://learn.sparkfun.com/tutorials/how-to-use-a-breadboard/all

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31

Ok now it is clear what you mean. I will go for the prototype boards then. :+1:

I will wait now for everything to arrive, then I will come back to this thread. :slight_smile:

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32

Esp-board that I pointed before is more "universal", especially for beginner. It also has 3 serial ports for sensors, C3 has only 2.

ps.
Don't worry to die if you already bought them, you can use I2C bus for sensors anyway, you just need to configure them separately for that.

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33

Which one you mean exactly, I checked and only found the one mentioned from me? You have a link again if you mean something different? I was to busy today and didnt ordered the boards yet. So if you can recommend the right one it would be great.

34

Post#18
For a link, where you live?

1 Like
35

Europe/Germany

I thinks thats the one I have linked? :smiley:
Or this one

36

Yep, like I already wrote.
Or if on budget:
https://www.amazon.de/-/en/Diymore-Development-NodeMCU-Module-Bluetooth-3-Items/dp/B09Z6RLS7R/ref=sr_1_5?dib=eyJ2IjoiMSJ9.ZxuRXiQudj-LXN0EXk8CWib9U0HwOohIh5DT3S-JO_nKP7eplyREsJhQ5YSjknTaelIbf4sUckyLBGBDgfd4mAWhNg5d57_VcFafR4Oxlafp5ouTL1jiZLC0cSr5cGMhL8LgzfzKVm8i3lGPt2qRUiNpT8Alq57nY44wDYmrMicTBjFx7qQj9ZSk8cRbJsXQimQYzKo-ABqju9BzXCWQgWDLtTFypFOLermt7mBwPdc.tgHiSa4NPmvZASChxOz8_INCn9D9ehSKv1KyE8cpgBQ&dib_tag=se&keywords=ESP32&qid=1724956008&sr=8-5

1 Like
37

Ok thans. I will go for the Amazon link I mentioned in #35.

If I compare the budget to what it would be if I go for standard sensors, that maybe have some valves on it maybe and dataloggers, then I think this is more than fine. The costs right now are around 1500$ for sensors and stuff. Thats more than fine... :+1:

38

That's what I wrote earlier. Buy 9 of them.
I rarely use something else than Esp32-boards.

39

Nothing is wrong with the classic ESP32 board.
The newer variants have all kind of small improvement and I think that the ESP32-C3 is a "normal" board as well.

When bought from LOLIN/Wemos, then I have a little more confidence in the quality because there is a brand behind it.

I mentioned Mouser.com, but in Germany there is also Reichelt.de.

40

I agree. But Esp Wroom32 is the oldest, most common and supported chip out there. It's like "Arduino Uno" of Esp32 family. And here 3 serial ports can make life easier as well.