“I am going to show you how to quickly build a plug & play CO2 sensor where all elements of the project will be connected with DuPont wires.
There will only be 5 points that need to soldered, because I did not solder before this project at all.
The sensor will have a display where the measured values will be shown every 5 seconds in a big enough Helvetica font.
The housing will be made with a laser cutter out of 4mm simple plywood. All elements will be glued together. A premade container can be an alternative. The display and the sensor will be held in place with duck tape.
The code of this project is put together from 2-3 sample codes I had. It is not sophisticated or pretty but as I did not know anyhting about coding since 2 weeks ago I think it is pretty solid.
The perfect thing about this set up is that once the code is loaded on the NodeMCU/ESP8266 it automatically starts when the power is connected to power and runs as long as the board has power.
In case you do not have a power socket the NodeMCU/ESP8266 can run on a battery pack for good amount of time.
The sensor is already sitting in an elementary classroom and has been working flawlessly for a couple of days so far. It provides the basis for when windows need to be opened to let in fresh air.
You will need the following supplies:
- Good soldering iron with adjustable temperature and a very small tip
- Solder (lead free)
- Cleaning wire for soldering iron
- Duck tape
- Third Hand Soldering Station with Magnifying glass
- Micro USB cable (from smartphone)
- Smartphone charger (5V, 1A)
- Dupont Jumper Wires 20cm - 2,54mm female to male 6,99 Euro
- Dupont Jumper Wires 20cm - 2,54mm female to female - 4,99 Euro
- SGP30 TVOC /eCO2 sensor - 25 Euro
- 0,96 OLED Display I2C Display (SSD1306) 128x64 Pixel - 6,29 Euro (3 Pack 12,49 Euro)
- NodeMCU LUA Amica Module V2 ESP8266 board - 5,99 Euro (3 Pack 13,79 Euro)
- NodeMCU I/O Breakout Board - 4,50 Euro
- 4mm Plywood sheet - 2 small zip ties (not displayed in my picture)”