Last modified April 16, 2021
No doubt, things enter through the eyes and a color touch screen for our homemade CO2 meter take the project to another level. Who can resist a nice, full-color touchscreen that's more than fair size?
We already have a quality CO₂ meter, with lots of functionality and expandability, at a low price. Now it's time to give a touch of luxury. Something we can do without, but, What milk!, let's give ourselves a whim to be proud and have something that, by showing it to our friends and family and saying that "I did it," causes the Wow!
Here we have the creature in question, in one of its first versions (don't worry, it will improve over time and become more beautiful):
Its installation could not be easier ... just connect four cables, load the file that I am going to provide below on the screen's MicroSD card, and update and configure the meter.
The secret is in the choice of the screen: A Nextion smart display.
This screen is very special (and I recommend it to use it in any other project you have where you need a screen).
What makes this screen different from the others is that it is not a simple screen, but has integrated all the user interface, such as graphics, buttons, etc. and has its own microprocessor to manage all that, and we only have to tell it what data we want it to «paint» in a certain place or wait for the screen to tell us «I have been clicked in that place».
The big advantage is that you can design your own user interface with simple tools (I have done it with PowerPoint) without needing to have great technical knowledge.
I will have a "presentable" version shortly that you can download from here with all the instructions, so you can incorporate it into your EMariete Homemade CO2 Meter.
While I finish it If you want to buy it, I recommend doing it in this AliExpress link, which is exactly the same screen that I am using (so you will make sure you don't have problems):
If you buy it elsewhere beware because there is an identical version, but in Chinese What next You can only use it with the Chinese editor (If you know Chinese you can ignore this comment 😉).
You already know that this article is an extension of the "eMariete Home CO2 Meter". If you haven't read it, start here:
Add a touch screen to your CO2 meter
To add the touch screen to your meter, you will need the following:
- The right Nextion display
- The file that you have to load on the screen
- A version of ESPEasy that supports the screen
- Configure the plugin
- Add the rules you need
I guess you already have the screen correct. It is important that it be exactly the same model so that the file that I have prepared works for you. Be careful because there is many models Nextion screens with minor differences and it may not work for you. I recommend that you buy it in the link that I have put before.
TOhere you can download the file HMI for Nextion display. You just have to load it with the Nextion editor on your screen and adjust the rules.
Have an account that the Nextion plugin it is not included in the normal build by ESPEasy. You will need the build that includes "TEST" in the name (it is in the full package that you download from the ESPEasy releases page on GitHub).
For example: "ESP_Easy_mega_20201227_test_ESP8266_4M1M_VCC.bin"
Save it to your ESP8266 and add it as a device in the drop-down of the "Devices" tab:
Now you have to configure Nextion device so that it is as follows (click on the image to see it complete):
Logically, you will have to change device names to yours. For example, in line 1, if your sensor is called CO2 and the value is called PPM, you will have to put [CO2#PPM].
With this, your screen would be working and every 15 seconds (the value indicated in the configuration in «Interval») the values will be updated.
It is still pending to implement the tactile part and its rules, since, although you can click with your finger and switch between the different screens, it is still not finished implementing and ESPEasy doesn't get those clicks. I encourage you to move through here and share your progress in the Telegram group so that other users can benefit.