ESP32: Running Webserver alongside OpenPLC - Control variables via Web-GUI? OpenPLC - General Discussion > OpenPLC on Arduino
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Junior Member 3 posts tefod Junior Member 3 posts
tefod
Hi everyone,

I'm using OpenPLC on an ESP32 board and would like to add a small web server alongside it. The idea is to create a simple web interface (e.g., accessible from a smartphone) to change parameters like pulse time and pause time - basically using a webpage as a mini HMI or SCADA.

There are many ESP32 projects where a web server is included by default (like Tasmota, WLED etc).

Is it possible to run OpenPLC and a custom web server at the same time on an ESP32? And how can I pass values from the web interface (like sliders or input fields) into OpenPLC variables, such as %MW0 or %MW1, so I can use them in my ladder logic?
Has anyone done this before, or are there any examples or tips on how to integrate OpenPLC with a web front end on ESP32?
Thanks a lot!
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Draxcat Junior Member 26 posts
Draxcat
I'd like to know that as well ta
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thiagoralves Admin  9,699 posts
thiagoralves
You might be able to do that using an Arduino Extension on your program. OpenPLC does not provide any native support for a webserver. You will have to write the webserver code yourself in the Arduino Extension. There are several Arduino Extension examples at the file->example menu for you to check
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tefod Junior Member 3 posts
tefod
Thx hanks for ur reply 😊
Actually I know how to run a webserver with Arduino Extension or PlatformIO. My issue is coexistence: once I flash OpenPLC, it overwrites the whole ESP32, so the webserver is gone.  What I’m looking for is a way to run both at the same time - the compiled OpenPLC logic plus a small web frontend to interact per Web with this logic.

I guess it might also be enough if I can just take the C code that OpenPLC generates from IEC61131 and somehow integrate that into a PlatformIO project.
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thiagoralves Admin  9,699 posts
thiagoralves
That’s exactly what an Arduino Extension does. It allows you to run Arduino code alongside your PLC code on the same board at the same time.
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tefod Junior Member 3 posts
tefod
Ah, now I get what you meant - the Arduino Extension inside OpenPLC itself. I hadn’t noticed that before (and I think it’s not really documented, or at least I totally missed it). I just searched a bit and found this blog post respectively this video about it, and it looks exactly like what I was trying to do.
That’s a really good hint, thanks a lot - and also for the hint with the examples!

I’ll go throughgive it a try and will post here how far I get with it. Appreciated!
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