Max packet size in protocol is 256MB.

The broker can limit that what is your broker's limit? Probably a lot less. Check the mqtt broker first.

Tom

I think the idea that investigating and defining the problem isn't necessary is an interesting approach to problem solving. The wrong approach I also think. It is incumbent of the poster to bound the problem. The methods of bounding are simple but necessary. Before I choose a solution I assure I kno...

I am not sure where the bottleneck is from your description.
Connecting to an mqtt server involves the server.
Have you used verbose on the sever or used Wireshark or investigated where the roadblock is? I recommend you identify the problem first.

Tom Meyers

I recommend you start here:

https://www.programiz.com/c-programming/c-strings

Tom

The replies all address increasing stack size. I suggest a different approach: define the problem the code as a whole is to solve then consider the various solutions and their data structures.

And answer: what data structures besides a stack can be used.

Tom Meyers

on the esp32 datasheet pg 28, it says "each digital gpio can be configd with pullups or pulldowns" There are several kinds of GPIOs: digital only GPIOs, analog enabled GPIOs, capacitive touch enabled GPIOs, etc. Analog enabled GPIOs can be configured as digital GPIOs. Capacitive touch enabled GPIOs ...

https://www.digikey.com/en/articles/how ... and-relays

Good write up.

Tom

Oh yes.

Bounce.

The signal is bouncing as it opens and closes.

If you have a scope take a look.

Solution:. Denounce sw logic or denounce in hardware. I usually denounce in s/w.

Tom

I have built a configurator in java. It is to build variants of sensors configured from a library of modules. Each module has a companion xml of prompts, rules, resource items used. I had an information block interface between modules. You picked one OS root / dispatcher and any sensor combination. ...

If you can then run mqtt broker in verbose mode while you observe the problem.