- 1 Features
- 2 Print
- 3 Print file
- 4 Connections
- 5 ESPEasy configuration
- 6 Step-by-step video tutorial
- 7 Front cover
- 8 Forthcoming improvements
- 9 User boxes
Many of the blog's readers have asked for a 3D printed box for the CO2 meter.
OK, challenge accepted!
I have designed a customised box for 3D printingsimple and easy to print, no need for brackets or bridges.
The main ones in features and benefits of the box, are as follows:
- Easy to print (without brackets and bridges).
- Design with thermal dynamics to conduct heat away from the CO2 sensor
- System of solderless NodeMCU installation (optional)
- Ready to install a 0.96″ OLED display
- Prepared for the installation of LEDS for colour-coded displays
- Prepared for buzzer installation
- Design of custom vinyl front cover
The box is very easy to print, although, as it has a certain surface area, it can give problems with warping (lifting of the corners) depending on the printer and its settings. when printing with ABS.
I I have printed the prototype with PETGalthough could be done perfectly well with PLA.
In a way, the PLA would be better because it is more stable and the measurements are more accurate.. This is especially important for the NodeMCU pins (I had to rework the holes with a small drill bit).
The box does not bear any stress and is structurally robustThe 10% can be printed with a 10% infill without any problem or risk of it being too flimsy.
The printing time, in my case, has been of approximately two hours. Depending on the printer, speed and desired quality, the printing time can vary considerably.
I have left the STL file for printing on Thingiverse. You can access it here.
The back cover, which I have not yet designed, is missing.. This is a first version and I will probably make another version with some improvements I want to introduce, so I will take the opportunity to design the back cover already for the new version.
If I didn't make the new version, I would design the back cover for this one.
The video covers the basic details needed to connect the OLED display. For more information, I recommend viewing the article Connecting an SSD1306 OLED display to ESPEasy.
Diagram showing the connections from the NodeMCU to the SSD1306 display.
Diagram with connections from NodeMCU to WS2812 LEDs (Neopixel)
For more information, see the article Connecting and controlling WS2812B LEDs to ESP8266 with ESPEasy.
Diagram showing the connections of the NodeMCU to the MH-Z19 or Senseair S8 module.
Both modules, MH-Z19 or Senseair S8, are compatible in terms of connections, so the connection will be identical.
Once we have made the connections, we have to configure ESPEasy to recognise the devices and include a few simple rules to behave the way we want them to behave.
Basically, we will have to do the following:
- Add the MH-Z19B sensor to ESPEasy
- Adding the SSD1316 display to ESPEasy
- Add WS2812 LEDS to ESPEasy
- Activating the ESPEasy rules engine
- Add a rule so that when it is switched on, the LEDs are switched off.
- Add a rule to change the colour of the LEDS depending on the CO2 level.
Add the MH-Z19B sensor to ESPEasy
This article, which you are reading, is about the 3D printed box. It is assumed that you already have a working home CO2 Meter. If this is not the case, I recommend you to see the article of the homemade CO2 meter and its video. Here you will find all the necessary details and a lot of useful information.
Adding the SSD1316 display to ESPEasy
The connection of this display is very simple and is explained in detail in the video.
I will not repeat their configuration here, as in the article Connecting an SSD1306 OLED display to ESPEasy you have very detailed instructions on how to connect the display and how to set it up with a very detailed video.
Add WS2812 LEDS to ESPEasy
Connecting WS2812B LEDs to our board and using them with ESP Easy is child's play. Only three connections are required.
Its connection and use are explained in detail in the video below, so you should not encounter any problems.
I recommend you to see the article Connecting and controlling WS2812B LEDs to ESP8266 with ESPEasy where you can find all the connection details, the rules you have to create, etc.
Want to add a buzzer?
The box is prepared for the installation of a buzzer, In article Using a buzzer with ESPEasy you have everything you need for connection and use.
Step-by-step video tutorial
Although the assembly is very simple, and is largely covered in the video of the assembly of the Homemade CO2 meterI have created a video with all the details of how to assemble the meter in a box, with specific instructions for connecting and configuring the OLED display and LEDs.
In it you will find explanations, details and tips of all kinds.
Along with the STL file of the box, on Thingiverse, I leave you also the front cover in SVG vector format.
I I have cut the front in adhesive vinyl with a cutting plotter.but you can print it out with a normal printer, cut it out by hand and glue it in. or do it laser in another type of material.
I leave you also the front cover the format of Silhouette Studiowhich is the cutting plotter I use.
In the next version of the box, which I intend to make, I intend to introduce the following improvements:
- Widen the LED gap to 10mm to be able to install the LEDs. LED strips standard flat shape.
- Provision of holes for the installation of 5mm round LEDs for those who prefer it (e.g. for normal RGB LEDs).
- Change the position of the buzzer to leave the front panel clean and allow the installation of the buzzer modules most common.
If you want to suggest any additional improvements, you can leave them in comments.
The idea is not create several versions for different parts (e.g. one for NodeMCU and one for Wemos D1 Mini, whoever wants to put in a Wemos D1 Mini can leave it air-wired) but also make improvements extending functionalities or improving usability.
Some users have designed their own boxes and some of them have actually improved my design by a lot!
If you have designed a box, don't be shy, let me know so I can include it.
Here are the boxes designed by users with the links to download them.
Danimod User Box
One box very elegantin my opinion. In the following video you can see it in detail.
You can download it here.
The screws for the cover are M2x7.
Danimod has also designed an optional bracket for your box which, to me in particular, looks phenomenal. You can download it from the same site. Also, as you can see, he has fitted his meter with LEDs that change colour with the CO2 level.
Nacho User Box
Nacho (nacho at pearquitectos.com), en architect expert in healthy and efficient housesand has designed a box with a very interesting design, inspired by Netamo.
You can download the STL from the box from hereso you can print it out.
Contracovid User Box
The user box Contracovidbased on that of Danimod (in fact, you can use the same cover), it is an adaptation to fit the Dupont connectors (so as not to have to weld) and dispensing with the OLED display.
In the following picture you can see the internal distribution of the components.
You can download the STL from the Contracovid box. from hereif you want to print it (you know, use the same cover as the Danimod box).