ESP32 Thermostat
WiFi thermostat developed around an ESP32 circuit + OLED display. Particular attention has been paid to the WEB interface (thanks to my friend Stéphane Calderoni for his help) compatible with all web browsers and smartphones.
If you are interested in buying this project as a kit of parts please go to its Elektor Jumpstarter page. There you'll find a slightly improved & extended version of this project renamed to 'Automator'. If enough people sign up for a kit, Elektor will launch its production.
It was while making the excellent Elektor Wifi Thermostat that I came up with the idea for this achievement..
Roy Aarts & Clemens Valens of Lab Elektor have been able to optimize the use of ESP8266
I tried porting their software to an ESP32, but gave up in the face of the work it took.
So I decided to start from scratch, taking inspiration from what had already been done (Web interface, NTP clock, regulation with programmable hysteresis, etc.), but by significantly improving the Web interface and its shortcomings at the time ( in particular the Java script did not allow a real real-time refresh of the user interface).
I have also decided to add a small OLED screen, which is very practical and which allows this thermostat to be used even if the WiFi connection is interrupted (degraded mode).
It was while making the excellent Elektor Wifi Thermostat that I came up with the idea for this achievement..
Roy Aarts & Clemens Valens of Lab Elektor have been able to optimize the use of ESP8266
I tried porting their software to an ESP32, but gave up in the face of the work it took.
So I decided to start from scratch, taking inspiration from what had already been done (Web interface, NTP clock, regulation with programmable hysteresis, etc.), but by significantly improving the Web interface and its shortcomings at the time ( in particular the Java script did not allow a real real-time refresh of the user interface).
I have also decided to add a small OLED screen, which is very practical and which allows this thermostat to be used even if the WiFi connection is interrupted (degraded mode).
Discussion (9 comments)
Shunth 3 years ago
Could the software be revised so that the temperature range is lower? So my temperature min 45 degrees, temperature max 60 degrees and alarm 38 degrees? If the temperature is in the min max range, everything is OK. but if the temperature is 38 degrees the relay should switch until max (60 degrees) is reached.
Reply
ybourdon 3 years ago
In fact there are 2 modes: cooling or heating.
Please check that the box is correctly selected in parameters: (use of a cooler check box, use of an heater uncheck box).
Cooling mode :
min <T < max : Relay OFF is temperature is decreasing and Relay ON if temperature is increasing
T < min : Relay OFF
T > Max Relay ON until the min temperature is reached
Heating:
T < Min : Relay ON until the max temperature is reached
T > Max : Relay OFF
min < T < max : Relay ON if temperature is increasing and Relay OFF if temperature is decreasing.
Alarm temperature should be higher than max Temperature.
cooling mode : alarme is sent via email (display is blinking red) but Relay stays ON to continue cooling the room.
heating mode : alarm is sent by email (display is blinking red) but Relay OFF to prevent a fire !
I hope it will help you !
Regards.
Yves
Please check that the box is correctly selected in parameters: (use of a cooler check box, use of an heater uncheck box).
Cooling mode :
min <T < max : Relay OFF is temperature is decreasing and Relay ON if temperature is increasing
T < min : Relay OFF
T > Max Relay ON until the min temperature is reached
Heating:
T < Min : Relay ON until the max temperature is reached
T > Max : Relay OFF
min < T < max : Relay ON if temperature is increasing and Relay OFF if temperature is decreasing.
Alarm temperature should be higher than max Temperature.
cooling mode : alarme is sent via email (display is blinking red) but Relay stays ON to continue cooling the room.
heating mode : alarm is sent by email (display is blinking red) but Relay OFF to prevent a fire !
I hope it will help you !
Regards.
Yves
Reply
Shunth 3 years ago
Thank you for your quick and accurate answer. I need a heating mode. With these enabled / disabled I somehow couldn't get along with the web interface ...... I switched it on or off directly in the software. (constexpr int CHECKCLIM = 0; // Mode clim = 1 ou mode thermostat = 0) Maybe that was my mistake ... I don't know ...
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HaSch 3 years ago
Hello Yves,
after testing a while I found out that the ESP32 board is falling back into AP mode after a while even if it is still connected to my local network. I think AP mode isn't permanently switched off after connecting to a local network.
Best regards,
Hans
after testing a while I found out that the ESP32 board is falling back into AP mode after a while even if it is still connected to my local network. I think AP mode isn't permanently switched off after connecting to a local network.
Best regards,
Hans
Reply
ybourdon 3 years ago
Hello Hans,
Sorry for this late answer.
I use the system for more than 1 year and I have never been return to AP mode (except when loosing my WIFI network which is OK).
It seems that your board is rebooting ans doesn't find your WIFI at startup.
Can you please check your Power Supply.
It is very important to have at lest 600mA for the WIFI works fine. A standard USB is not enough to my mind.
Best Regards,
Yves
Sorry for this late answer.
I use the system for more than 1 year and I have never been return to AP mode (except when loosing my WIFI network which is OK).
It seems that your board is rebooting ans doesn't find your WIFI at startup.
Can you please check your Power Supply.
It is very important to have at lest 600mA for the WIFI works fine. A standard USB is not enough to my mind.
Best Regards,
Yves
Reply
HaSch 3 years ago
Hello Yves,
the power supply is OK, it's the one soldered on your PCB. The board does NOT restart. The issue appears if the ESP32 Thermostat is running a while. I noticed that my PC is connected to the ESP32's network and doesn't have an internet connection anymore. In this case the Thermostat continues the connection to my local network but builts a new AP. My workaround is to prevent my PC (and mobile phone) to connect to the AP of ESP32.
Best regards
Hans
the power supply is OK, it's the one soldered on your PCB. The board does NOT restart. The issue appears if the ESP32 Thermostat is running a while. I noticed that my PC is connected to the ESP32's network and doesn't have an internet connection anymore. In this case the Thermostat continues the connection to my local network but builts a new AP. My workaround is to prevent my PC (and mobile phone) to connect to the AP of ESP32.
Best regards
Hans
Reply
ybourdon 3 years ago
Hi Hans.
The software checks and needs to be connected to the internet. NTP needs that to be updated.
I guess Rssi is fine ? (Green Orange or Red ?)
At home I have the fiber and my internet connection is very good.
I have also an AP wifi repeater close to the Thermostat.
Sorry not to be able to better help you.
Thanks if you can send a picture of your system !
Do you use 1.51 firmware update ?
Regards.
Yves
The software checks and needs to be connected to the internet. NTP needs that to be updated.
I guess Rssi is fine ? (Green Orange or Red ?)
At home I have the fiber and my internet connection is very good.
I have also an AP wifi repeater close to the Thermostat.
Sorry not to be able to better help you.
Thanks if you can send a picture of your system !
Do you use 1.51 firmware update ?
Regards.
Yves
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2 Comment(s)
HaSch 3 years ago
Hello,
in article you can read that of R9 and R10 only one should be soldered. But there isn't any explanation of this. Which one should be soldered in which case?
Best regards,
Hans
in article you can read that of R9 and R10 only one should be soldered. But there isn't any explanation of this. Which one should be soldered in which case?
Best regards,
Hans
Reply
ybourdon 3 years ago
Hello Hans,
As you can see in the diagram, both R9 and R10 are connected to capacitor C4. Indeed, an R / C filter protects the relay contacts by "absorbing" the spark produced by the switching of the relay. If your load is connected to the NC contact of the re relay, then R10 must be soldered, but if you use the NO contact, R9 must be soldered. Due to the high voltage that can be connected to the relay, it is essential to use a type X2 capacitor and to respect the power of the resistor. If the switched load is low (<25 W) then you can safely omit soldering R9 / R10 and C4.
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HaSch 3 years ago
Hi,
the settings and timer pages don't fit my phone's screen perfectly. I'm not able to see the lower part of the screens and it's not possible to scroll down. Please allow scrolling to fit this screen.
Also, there seems to be a newer version of the webserver as I can see in Elektor Magazine printed issue 9/10 - 2021. It's translated into English (instead of French as in your download files) and it may allow scrolling already.
Best regards,
Hans
the settings and timer pages don't fit my phone's screen perfectly. I'm not able to see the lower part of the screens and it's not possible to scroll down. Please allow scrolling to fit this screen.
Also, there seems to be a newer version of the webserver as I can see in Elektor Magazine printed issue 9/10 - 2021. It's translated into English (instead of French as in your download files) and it may allow scrolling already.
Best regards,
Hans
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HaSch 3 years ago
Hi,
unfortunately there is no link to download the files to get the PCB produced. I'm very interested in that can you provide the PCB files?
Best regards,
Hans
unfortunately there is no link to download the files to get the PCB produced. I'm very interested in that can you provide the PCB files?
Best regards,
Hans
Reply
Content Director, Elektor 3 years ago
Hi. The project was also published in Elektor mag. You can find a BOM and Gerber files on the article page, https://www.elektormagazine.com/magazine/elektor-183/59826. Thanks!
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Updates from the author
ybourdon 3 years ago
You can find it under the file Other.
Regards.
Yves
ElektorLabs 3 years ago
ybourdon 3 years ago
Heinz2 3 years ago
When I remove the USB connector from ESP32, the wifi connection is interrupted.
If I re-establish the connection between ESP and PC, the connection to wifi is re-established.
I would be glad to get an answer.
Thanks
ybourdon 3 years ago
TIMER OFF is correct. It only means that the relay always stays to OFF. So you don't have any regulation.
Perhaps I have to find another sentence . Instead of "Timer disabled", I could write "Don't care Timer".
My English is not so good, perhaps you have another idea ?
Thank you for your reply.
HaSch 3 years ago
ybourdon 3 years ago
I don't have this strange issue.
Also try to clear the cache of your browser to be sure to use the last js update.
Sorry if you have a bug I have never seen !
Regards.
Yves
HaSch 3 years ago
Regards,
Hans
HaSch 3 years ago
ElektorLabs 3 years ago
webserver.ino
String answer = ... + (mesureT == -127 ? String("Err.") : String(mesureT)) + ...String(mesureT) converts float to string with 2 decimals (default) (provided by ESP32 boards package)thermostat.js
temperature = document.getElementById('temperature'); ... temp = val.substring(11,15); ... let t = Number.parseFloat(temp).toFixed(1); ... temperature.innerText = t; )The last line replaces the string in the webpage "%TEMP%" by t (converted to string with one decimal).As we see, there are many places where things can go wrong. Furthermore, the value displayed on the OLED is obtained in another way, which explains why the two values may be different.
screen.ino
I don't know where things go wrong, but a good fix would be to convert mesureT to a string that is used by both screen.ino and webserver.ino:
Thermostat.ino
mesureT = floor( 10 * mesureT + 0.5) /10; // Only one decimal remains. sprintf(mesureT_str,"%.1f",mesureT); // Convert mesureT to string with 1 decimal.webserver.inoString answer = ... + (mesureT == -127 ? String("Err.") : String(mesureT_str)) + ...thermostat.jstemp = val.substring(11,15); // Verify boundaries! temperature.innerText = temp; // i.e. "%TEMP%" is replaced by tempscreen.inoUntested!
HaSch 3 years ago
Of course mesureT_str needs to be defined:After that it compiles without an error but the result is the same: OLED showing 1 decimal and in web interface the decimal is always 0.
Of course I uploaded changes in web interface to the board.
ElektorLabs 3 years ago
The substring boundaries 11 & 15 are wrong, they should be 12 & 16. The same is probably true for the relay className indexes, they should be moved to the right too.
Actually, this whole function is unsafe and should use string splitting instead of substring extraction. Also it would be much easier if the separators used by webserver.ino were not double spaces but just a single special character like '|'. Then the javascript parser could be something like this:
function setData(val) { var valParts = val.split('|'); time.value = valParts[0]; time.className = valParts[1]==1? "red":"green"; temp = valParts[2]; temperature.innerText = temp; relais.className = valParts[3]==1? "red":"green"; setTemperature(temp); }Untested!ybourdon 3 years ago
I will check tomorrow.
ybourdon 3 years ago
I have added an OTA facility.
I will published the whole code tomorrow (version 1.50).
I have checked and rechecked without any issue.
Can you check again your hardware Hans ? Did you put pull up as explained ?
HaSch 3 years ago
If you would like I can return my (working) version of the software with all comments completely translated into English language and the changes Clemens (ElektorLabs) suggested. But I did not yet build in splitting with '|'.
HaSch 3 years ago
ybourdon 3 years ago
I have also corrected minor bugs and included Clemens "splitting" suggestion !
If everything is correct I will include Hans translation in a next revision. Thank you so much !
HaSch 3 years ago
Edit: Maybe this idea is not so good. I will think about it.
ybourdon 3 years ago
It seems to me that you forgot to solder R14 witch is a pull up for IO22.
The OLED screen indicates TIMER OFF when no Timer condition is reached (either always ON or no selection on a particular day).
That seems correct to me !
Relay is OFF because TIMER is OFF.
tressieres 3 years ago
Thanks,
Laurent
tressieres 3 years ago
Thanks,
Laurent
ybourdon 3 years ago
https://www.elektormagazine.com/magazine/elektor-183/59826.
Please forget any previous software as many issues (including this solved by HaSch : thank you !) have been solved.
Enjoy !
HaSch 3 years ago
in web interface temperature is only shown as integer, it should be shown with 1 decimal place. I didn't find yet where to correct.
If "Timer Disabled" has NOT a check mark and NO weekday has a check mark the OLED is showing "Timer OFF". Is that correct? Any other combinations showing "Manual".
Best regards,
Hans
ybourdon 3 years ago
Is it possible you forgot to update SPIFF files ?
They must be in data folder.
Regards.
Yves
HaSch 3 years ago
img-2268.jpg (758kb)