Soft-AP documentation update

[aerlon]

In several places of the documentation one can read "the maximum number of stations that may be connected to ESP8266 soft-AP is five." or something along those lines. However, the softAP method has a int max_connection = 4 argument which represents "Max simultaneous connected clients". It would thus seem that the maximum number of stations that may be connected to ESP8266 soft-AP is four by default. This PR brings the documentation in line with the source code.

While looking into this issue I noticed that the topic may not be quite as simple as it first seems. Although the softAP method claims the max number of clients is 4, I've read other claims that the max is actually 8. @d-a-v even seems to have been able to get 12 simultaneous connections working (though I'm not sure if that test is applicable here), and there are some claims that the main limiting factor is actually only available memory.

Sadly I do not have enough ESPs to try where the max limit is for myself, so it would be good if @d-a-v or someone else with knowledge on this topic could confirm whether the max actually is 4, 8, 12 or something else.

[d-a-v]

I was telling that I could run 12 tcp connections simultaneously (layer3, in STA mode, with a PC), not having 12 wlan clients simultaneously connected to the Soft-AP (layer2layer1).
I currently have not that much esp to test with. If there is a limitation, it should come from the internal firmware.
If there are no other mention in the nonos-sdk documentation, then you at least found an official statement from espressif.
IMHO, that information should also be stated in the sources (with reference).

[aerlon]

OK. Thanks for the clarification.

I agree, providing a reference is a good practice. The question is which reference…

Looking at the latest NonOS API reference one can find the following at page 143/166: uint8 max_connection; // default 4, max 4. Which would seem to go against a lot of the other sources I've found indicating a max of 8, including the previous one from Espressif . It is all very confusing.

[devyte]

I think max wifi clients is 8, limited by the sdk. Espressif document 2C api reference should explain it. I can't look up the specific section right now, though, still limited to my broken phone.

[devyte]

To clarify, the sdk max used to be 4, and it was increased to 8, but the max default of 4 was kept. Now, if you want more than 4, you have to set a higher max explicitly. At least that's how I remember it.

[aerlon]

OK. If Espressif document 2C api reference is the following: https://www.espressif.com/sites/default/files/documentation/2C-ESP8266_Non_OS_SDK_API_Reference__EN.pdf
I was unable to find any other information than the one at page 143 I mentioned above.

However, I've since discovered an Espressif forum thread where an employee states "ESP8266 soft-AP can connected to 8 stations at most." . I'm guessing page 143 in the NonOS API reference has not been updated since they increased the max.

The PR has been updated to reflect that valid values for max_connection is 1 to 8, and a reference has been added.

[d-a-v]

Thanks !

While you are at it, please check this recent #5082 PR
(not really wanting to be picky :)

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[devyte]

Ok so espressif's doc needs to be updated :P
There is mention in the sdk releases changelog that the max allowed is 8 stations.