There are many people who are looking for a CO2 meter with large display that can be seen from a distance for installation on catering, schools, gymnasiums and the like.
The truth is that the system is so flexible which, as you will see below, not only allows for the creation of huge display panels (from 5″ mobiles to 7″ tablets, 12.9″ iPads up to 100″ Smart TVs), but it is possible to create extremely small screens, like the floating teacher window I show below.
During this time I have carried out various prototypes and experiments with different types of displays. I have used large seven-segment LED displays, matrix panels, addressable panels, etc.
The problem I was facing was, on the one hand, the rigidity (each person has different tastes and needs and it would have been necessary to adapt the system to many different types of hardware) on the other hand the construction difficulty and the cost.
Finally, I said to myselfwhy not take advantage of the fact that the CO2 meter has a complete integrated web server and use it for display on all types of screens??
Said and done, I rolled up my sleeves, I got to work and today I bring you the result...
It's not finished yet, but I want to give you a taste of what's to come.
My knowledge of CSS (I know my way around it, but I haven't mastered it) makes it go slower than I would like, and gives me a lot more work than necessary.
If you have CSS knowledge and want to collaborate, please write me through the Telegram group. With a little help we can achieve something very, very attractive and interesting and many people in need will be able to benefit from it.
Benefits of CO₂ on the big screen
Being based on HTML, CSS, and JavaScript (the web technologies)There are many benefits to be gained from this large screen display system.
Apart from the obvious benefit, which is possible viewing information remotelywe would have the following:
- Great flexibility content and design
- No investment. There is no need to no more than the homemade CO₂ meter on this blog (and the device where you want to display it, of course).
- Adaptable to all types of devices (Phones, tablets, computers, Smart TV, etc.).
- Possibility of design responsive (self-adaptation to the display device).
- Multiple simultaneous clients.
- Possibility of integrating other sources of information.
- Complete freedom of choice colours, sizes, fontsetc.
- System fully autonomous (no internet connection required)
- No library dependencies such as jQuery or others.
- Customisable logo (I take everything) easily.
- Possibility to define several pages with different layouts.
Possibilities of the CO₂ meter on large display
Although, for the time being, it is only a prototype (I will soon publish instructions and the necessary filesOn this page, so that you can do the same), the visualisation system already has the following functionalities:
- Display of any parameter emissions from the CO₂ meter (such as temperature and humidity, in these examples).
- Real-time visualisation without reloading the page.
- Display of historical graphs (from Thingspeak or others).
- Colour changeaccording to the level of CO₂ (traffic light effect) with user adjustable levels.
- Possibility of displaying external data.
Of all of them, which will be useful to one person or another, I think that the most interesting and useful for everyone is that the display always shows the current CO₂ value. You don't need to reload the page or press any buttons to get the current data.
Display devices
There are many devices on which CO2 visualisation is possible. Whether you need a small stand-alone system, with a tablet, for example, for medium-sized spaces such as a Large format TV, for large venuesyou always have a choice.
Tablets
The tablet is the display device par excellence.
There are really cheap Android tablets, even older tablets, that you may not use anymore, that you can use for this, giving them a new youth.
They are ideal to put them on fixed to the wall with some kind of bracketlike this one:
- DAMAGE-FREE INSTALLATION AND REMOVAL: Installs in less than 2 minutes using damage-free 3M Command Adhesive Strips (included) that are rated to hold up to 2.25 kg each; no screws or holes required; designed for use on flat, smooth surfaces (screw-on versions, Koala Mount with screws and Koala Mount 2.0, sold separately).
- UNIVERSAL: Uses 2 separate mounts that can be configured to any distance required by your device, allowing full width compatibility. This includes iPads 1, 2, 3, 4 and the new iPad 9.7, Pro, Air, Air 2, most Samsung tablets and many more. The mounts will fit any device 11mm thick or less. Can be used with protective cases as long as they are less than 11mm thick.
- SIMPLE: Super easy to attach and remove, can be set to portrait or landscape mode. No extra accessories needed; no special cases or additions to your tablet. Full access to ports/buttons on devices larger than 7-8'' can work best with our Koala Mount 2.0. Pre-installed cable clips to help keep your cable tidy.
- MOUNTING: They come with 3M Regular Command strips that are not designed to work in areas exposed to high temperatures or humidity (such as the bathroom). For this, 3M manufactures special strips that are water and heat resistant. In addition, Command strips do not tend to work well on textured surfaces and some papers. We highly recommend our Resistance Test. Command strips are not reusable after they have been removed.
- COMPATIBILITY NOTE: While it fits most popular tablets, the mounts can lock ports/buttons on both sides between 3.8cm and 9.5cm from the bottom (7-8'' tablets such as the iPad Mini can have ports locked in landscape mode - if this is the case see our Koala Mount 2.0).
Smart TV
Most Smart TVs in recent years support HTML, CSS and JavaScript (internet technologies) so it will be very easy to use them as a CO₂ display device.
This is a perfect solution for really big rooms where we need information to be seen from all points.
We can put a SmartTV from 4K and 58″for relatively little money than will be seen from far away.
No products found.
regular TVs (with the help of, for example, an Amazon Fire TV Stick)
If you have a slightly older television, or any monitor with HDMI inputYou can use it to display CO₂ levels using, for example, a Fire TV Stick:
- Our most affordable Fire TV Stick: fast streaming playback in Full HD quality. Comes with Alexa Voice Remote Lite.
- Press the button and ask Alexa: use your voice to search for content and start playback in multiple apps.
- Thousands of apps, Alexa Skills and channels, including Netflix, YouTube, Prime Video, Disney+, DAZN, Atresplayer, Mitele and more. Subscription charges may apply.
- Amazon Prime members have unlimited access to thousands of movies and series episodes.
- Live TV: watch live TV shows, news and sports with subscriptions to DAZN, Atresplayer, Movistar+ and more.
Teams of teacher, monitor, supervisor, etc.
It's not all giant screens. Sometimes the essence comes in a small bottle.
Sometimes it is important that the teacher, monitor, supervisor, etc. have the possibility to see permanently the level of CO₂ in the environment.
In this image (bottom right) you can see how a small window "floats" on the teacher's computer over and above what he or she is doingallowing you to view the CO₂ level at all times. The teacher can drag the window to relocate it, resize it and, of course, hide it.
Limitations
As with everything else, this system also has its limitations.
These are the ones I know of so far (if you discover another one let me know so I can include it).
- Low security: Not valid if you want to show "sensitive" data. It is intended for public data, so you don't care if someone, in whatever way, connects and gets it.
- Concurrent users: The microcontroller used in the CO₂ meter (ESP8266) is not a real web server, so it won't support many connections at once. I have tested it with four simultaneous connections and it works, but I don't know how many it would support. This is intended for connecting a few display devices, not for a bunch of people connecting to the CO₂ meter directly.
Examples of visualisation
I will leave you here some examples of what I am doingto give you an idea:
Recommended Tablets
Almost any tablet should do as a display device. Of course, there are so many models that it is difficult to know a priori whether any of them will not work for some reason.
Most importantly, when used as a display device is the tablet is capable of being on and charging simultaneously. Almost all of them do, but not all, I, for example, have one that, even if it is plugged inThe battery consumes more than it charges, so after a few hours it shuts down.
I recommend that you buy your tablet from Amazon, where you will be able to return it and exchange it for another one if it does not work, without any problem.
Here are some of Amazon's best-selling tablets:
- Immersive cinematic experiences: thanks to a superb HD display and Dolby Atmos-equipped enhanced dual stereo speakers, you're sure to get a truly immersive experience.
- Powerful gaming: Take a break and play your favourite games with the Lenovo Tab M9 tablet. Games and browsing run smoothly and fun, as it is equipped with the powerful MediaTek Helio G80 eight-core processor and a large storage capacity.
- Google Lens: Google Lens lets you search what you see, do things faster and interact with the world around you. Translate text, get help with your homework or quickly identify products, plants and places.
- Long battery life: Enjoy your favourite shows or movies uninterrupted and relax for longer with the Lenovo Tab M9 tablet's long-lasting battery. And with expandable microSD card storage*, you can carry a library of your favourite movies and shows in your pocket (microSD card sold separately).
- Surround reading mode: Let the Lenovo Tab M9 tablet create the ideal ambience with its Surround Reading Mode that adds ambient sounds to your reading time. Plus, with TÜV certification for screen eye protection, your eyes can relax too.
- 🔥【Android 14.0 & Octa-Core 2.0GHz】🔥The PIXPEAK tablet features the latest Android 14.0, which runs smoother, faster and with better privacy. It also features a powerful Octa-Core processor running at up to 2.0GHz for exceptional performance that enhances program execution speed and smooth web browsing.
- 🚀【36GB RAM+128GB ROM & 8000 mAh Battery】🚀The storage of PIXPEAK tablet can be expanded up to 36GB (12+24) RAM, of which 24GB need to be activated in the settings. Thanks to the 128GB ROM and 8000mAh battery, you can switch between applications quickly and without delay, allowing you to watch video in a long life.
- 🌐【Better Internet connection-Dual band 2.4GHz/5GHz】🌐The PIXPEAK tablet can be used via a 2.4GHz/5G WiFi connection or a mobile hotspot; the new WiFi receiving and transmitting channel improves the speed and stability of the network connection. No matter where you are, you can always use the Internet.
- 💖【5MP+8MP camera and 10-inch tablet】💖The PIXPEAK tablet features a 5MP+8MP camera and a large 10-inch screen, giving you and your friends a clearer and smoother view during video calls.
- 🎁【2-in-1 Tablet and Professional Customer Service】🎁The PIXPEAK tablet includes a mouse, Bluetooth keyboard, OTG adapter, protective case, charger, headphones and much more. You can use the tablet as a small laptop. If there is any problem with the use, our professional staff will help you solve the problem within 24 hours.
- 🔥【Latest Android 14 and high-performance 8-core processor】. The 10-inch tablet tablet is upgraded to the Android 14 operating system, ensuring that every swipe is smoother and more responsive than ever. The excellent 8-core processor, using advanced A55 architecture and cutting-edge 22nm process technology, ensures the processor achieves a balance between high performance and low power consumption, while maintaining a solid 2.0GHz performance, bringing an unprecedented smooth experience to your tablet.
- 🚀【10-inch FHD display and Widevine L1】】. The Android 14 tablet is equipped with a 10-inch FHD Full HD display with a resolution of 1280 x 800 pixels, and also incorporates T-Color 2.0 colour optimisation technology, allowing visual enjoyment to leap onto the screen. The Android tablets support Widevine L1 standard, ensuring that it can provide a stable and smooth system environment for both daily operations and intensive applications. You can also install your favourite third-party apps, such as LINE, Netflix, YouTube, Facebook, Twitter, etc.
- 🔥【10 (4 + 6) GB RAM + 128 GB ROM + 1 TB expansion】. The 10-inch Android tablets feature a powerful storage combination of 10GB RAM (4GB + 6GB achieved through expansion technology) and 128GB ROM, which is enough to hold your rich digital life content, including HD videos, lossless music, massive eBooks and a variety of online course materials. It can also be expanded with a microSD card/TF card to add up to 1TB of additional storage (note that additional storage capacity is provided by purchasing your own microSD card/TF card.
- 🔋【5000 mAh battery + 5MP / 8MP camera】. The tablet is equipped with a large 5000 mAh battery. Whether you're immersed in watching videos, surfing the web or listening to the melody of music, you'll have access to a steady stream of power to keep every moment of entertainment and learning flowing. The back of the tablet features an 8MP HD camera with flash that makes it easy to capture every moment of life even in low-light environments, while the 5MP front camera is designed for selfies and video calls, ensuring a clear and natural image of every selfie and video call.
- 🚀【WiFi 6 + Bluetooth 5.0】. This 10-inch tablet is equipped with cutting-edge 6th generation WiFi technology, built-in high-performance dual-band WIFI chip and can support wireless network connection in 5GHz and 2.4GHz frequency bands. This design not only ensures the stability of network connection, but also greatly improves the speed and efficiency of data transmission. Whether you are at home or on the go, you will enjoy a smoother network experience.
- 👍【Big 8000mAh battery】OUKITEL OT6 tablet 10 inch is equipped with a powerful 8000mAh battery, providing long battery life and excellent battery performance. With a standby time of up to 1250 hours, it provides a stable power supply whether you are on the go or on a busy working day.
- 👍【WiFi 6 and WIFI 5G】OUKITEL OT6 cheap and good tablet is loaded with 5G wifi and WIFI 6 technology. WiFi 6 uses some new technologies and protocols to reduce network delays and provide fast and instant response. 5G WiFi offers higher bandwidth in the 5 GHz band and is generally less susceptible to interference than WiFi networks in the 2.4 GHz band.
- 👍【Widevine L1】OUKITEL OT6 best-selling cheap tablets supports Widevine L1, providing excellent HD content protection. It ensures smooth playback of your content while providing the highest level of digital copyright protection.
- 👍【16 GB RAM + 64 GB ROM】. OUKITEL OT6 WiFi 6 tablet has 16GB (4 + 12) of RAM and 64GB of ROM, which can also be expanded to 1TB. The powerful working memory helps you multitask smoothly and the large storage space can meet your daily needs.
- 🎁【Official Service + 1280*800】 Resolution. The OUKITEL OT6 10-inch tablet is equipped with 1280*800 resolution and offers a 30-day no-questions-asked return policy, two-year warranty, long-term technical support and 24 hours. online customer service. Choosing OUKITEL smart tablet means choosing a safe shopping experience and dedicated customer service, this is definitely the best gift!
- Enjoy its 11" WUXGA touchscreen with 1920x1200 px resolution and 90Hz refresh rate, allowing intuitive operation and smooth navigation through your multimedia content, games or documents.
- Take your productivity and entertainment to the next level with the 8-core MediaTek Helio G88 processor, 4GB of RAM and 128GB of storage expandable up to 1TB via Micro SD card slot.
- Its long battery life of 7040mAh allows you to use the tablet all day long and fully enjoy its multimedia with its 4 1W speakers optimised with Dolby Atmos, without having to constantly rely on a power supply.
- Work, learn or entertain anywhere: the Lenovo Tablet Tab M11 is easy to carry from place to place and thanks to its weight of only 465 g it offers you flexible usage possibilities in different environments.
- Trace, draw and get inspired with the included pen and turn your Tab M11 into a canvas to bring your imagination to life.
If you use any tablet sold on Amazon (whether it is included in this list or not) let me know, with the results obtained, so that I can advise users.
Hello,
Lately I follow your blog day by day. I am a teacher and I am about to start the CO2 meter project, with students. From what I can see in an image, it seems that you use Thingspeak to publish the sensor readings, I have tried but I have not been able to do it, I have just discovered ESPeasy and I still do not understand the platform well, nor MQTT. However, with Arduinoblocks I haven't had any problems. Could you point me to a tutorial to connect to Thingspeak? I don't think I'll have problems if it's in English.
I also noticed in the MH-Z19B video that there doesn't seem to be much difference between the results of the original MH-Z19B and the reference Senseair, right?
Greetings, and thank you very much for all the work you do and show us.
Thank you
Edit:: Checking the blog, I saw some instructions on the entry https://emariete.com/medidor-casero-co2/#Creacion_de_grafico_de_evolucion_de_CO so I will try to see what I can do.
Thank you very much.
Hello Alberto.
I'm glad you found the instructions on how to send the data to Thingspeak.
The differences between the measurements of the MH-Z19B and the Senseair S8 LP are not big, both sensors measure quite well. The Senseair S8 LP is faster at detecting changes.
If you have any questions, I'll be happy to help you. The best way is through the Telegram group: https://t.me/emariete_chat
Best regards.
Hi, can you please post at least the basics to be able to view the data on a tablet? Even if it's just the real time value! Thank you very much for the work! Best regards
Hello Jordi.
We are just taking it up again, with the help of our colleague Sey. Let's see if we can give it a good push and publish it soon.
Best regards.
Hi, how is this project going. I would like to try it out for my premises.
It seems to me that they are going to make it compulsory.
I've ordered the parts to start assembling it. I'll keep you posted with my problems 🙂
Best regards.