TCP/IP communication of several ESP modules memory crashes when calling client.remoteIP

Hello

I think I've been struggling with a problem for about a week now and I can't seem to solve it on my own and it's hard to find similar problems on the internet.... Namely, I want to communicate several ESP32 modules with each other using TCP/IP (one ESP is the server, the rest connect to it). Each ESP wants to differentiate by IP address and, depending on the address, put the incoming data into a specific variable. To read the IP address I use clien.remoteIP() - it returns the IP address, but if I call this function in a loop more than once my ESP gets a memory crash:

(message: Guru Meditation Error: Core 0 panic'ed (InstrFetchProhibited). Exception was unhandled.
Core 0 register dump:
PC : 0x000000 PS : 0x00060e30 A0 : 0x801100ad A1 : 0x3ffb3d30
A2 : 0x3ffccd7c A3 : 0x3ffccfb0 A4 : 0x3ffcb340 A5 : 0x3ffcb320
A6 : 0x0204a8c0 A7 : 0x0c04a8c0 A8 : 0x8010ff50 A9 : 0x3ffb3cf0
A10 : 0x3ffccd8c A11 : 0x3ffccfb0 A12 : 0x3ffb3d3c A13 : 0x00000044
A14 : 0x00000001 A15 : 0x0000006 SAR : 0x00000010 EXCCAUSE: 0x00000014
EXCVADDR : 0x000000 LBEG : 0xx4000c349 LEND : 0xx4000c36b LCOUNT : 0x000000

Backtrace: 0x00000000:0x3ffb3d30 0x401100aa:0x3ffb3d70 0x4011d011:0x3ffb3d90 0x40122019:0x3ffb3dd0 0x401272b6:0x3ffb3df0 0x401109cf:0x3ffb3e10 0x40088b7d:0x3ffb3e40

I should add that the crash occurs just when trying to connect clients to ESP
If I connect the modules without recognition everything is fine - I'm able to send a series of data (admittedly it goes slow, several times slower than via UDP because I've already done the same thing using UDP) but recognition is necessary to properly segregate the data - let's assume each esp sends data from a different sensor - the server has to collect it and process it... When I call client.remoteIP() only once, the program works (although not always, sometimes requiring several client resets)

Would someone be so good as to advise or guide me at least on how to deal with this? Maybe there is an example available somewhere?
I am also attaching the server code:
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and client code:
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Regards

Added after 44 [minutes]:

Plus a screen shot of the ESP Exception Decoder:

First of all, you don't close server-side client connections (client.stop() - rubbish collects in memory) in a loop(). Take a look at maybe an example of server-side client handling in ESP32:
https://github.com/espressif/arduino-esp32/bl...xamples/SimpleWiFiServer/SimpleWiFiServer.ino

Thank you for your reply

I have also tried the client.stop but to no avail

When the main loop looks like this I also get a crash when connecting the client:
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Added after 10 [minutes]: .

Reading the address and port of the client right after checking the presence of the client helps, however in this situation I don't know why but I get every other message:
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Added after 48 [minutes]:

However, when I try to do it as in the above code, I can't connect more than one client - the client sends, but the server doesn't print it to the serial (it only sees one client)

lotnik95 wrote:

However, when I try to do it as in the above code I am not able to connect more than one client - the client sends while the server does not print it to the serial (it only sees one client)

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You only have one instance of the WiFiClient object in the server code. If you had more, you could handle more clients.
https://arduino.stackexchange.com/questions/31256/multiple-client-server-over-wifi

Added after 1 [hour] 2 [minutes]:

Of course client.setNoDelay(1) should return to code .

That's right, inserting setNoDelay(1) helped and communication is fast - thank you very much! (although still several times slower than over UDP which surprises me, but never mind)

I still don't understand some things - the code was working fine, both modules were ok, now I restart it and I get crashes again when connecting a single client....

Knock the following line out of the loop().

Added after 9 [minutes]:

and after server.begin() in the setup() function insert:

the funny thing is that I can reset the client 50 times and nothing happens, I reload another working program, upload the one I uploaded here in the previous post and after 2 client resets it works and then it connects correctly every time, but when I e.g. restart the server module and it's a mess again

delete

it doesn't help and I remember that earlier lack of it also caused crashes, it is hard to understand what is going on there, I have 3 ESP32 modules and on each of them it looks the same

lotnik95 wrote:

the funny thing is that I can reset the client and 50 times and nothing,

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What server-side messages then appear in the serial port monitor?

Added after 4 [minutes]:

lotnik95 wrote:

but when i e.g. restart the modul that is the server and it is kaplan again

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And what in this situation? Just before the crash.

screen: left server, right client
screen: left server, right client

and with ESP Exception Decoder:
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Added after 54 [seconds]: .

The crash is only when the client connects, if it connects it just keeps sending data indefinitely - on the server I read the data and display it on the serial monitor.

Most likely malfunctioning WiFi.softAPConfig() in the server. Insert after WiFi.softAP() a small delay (100 ms), as below:b8 .
In addition, after WiFi.mode() insert WiFi.disconnect() and a small delay, in order to disconnect clients that were connected to the server just before it restarted: .