My ESP8266 connects to wifi without specifiying any SSID and password!

[jumpjack]

I modified BasicHttpClient example sketch to suite my needs, but I get strange results: ESP connects to "something" but I don't know to WHAT!
In a first time I left the default SSID and pwd of the source, so I expected no connection to happen... but ESP connected to my wifi network and properly downloaded a file from internet!
Then I completely deleted SSID and pwd:
WiFiMulti.addAP("", "");
Well... it's still working fine!
It connects to my network and downloads file from internet!

I guess the ESP is using ssid and pwd I previously specified in other experimental sketches... but I think it is not an acceptable way to work!

How can I get a list of previously accessed APs?
How can I get the name of currently connected network?
How can I get a list of WifiMulti() available methods ans properties?

But, above all: how can I trigger an error if I specify wrong password or non-existing SSID?

[retsifp]

Well, I think the WifiMulti-Library stores the APs inside flash and once you added an AP, it'll connect to it.
This behaviour is not documented here, but the function void APlistClean(void) (here) could be worth a try.

Please read also here, you can read your current SSID and PSK by calling

Serial.printf("SSID: %s\n", WiFi.SSID().c_str());
Serial.printf("PSK: %s\n", WiFi.psk().c_str());

[jumpjack]

By the way, in the .h file you linked, which I already had checked, I noticed just now the WifiAPlist structure, but I don't know how to access it, I only know basics of C/C++...

Thanks for the tip about current SSID/pwd

[retsifp]

APlist a vector of WifiAPlist_t. So I think it'll contail all the APs, but it's private and without some knowledge of C++-Programming, it won't be that easy to access it.

Edit: You'll need to add some serial output to that line inside ESP8266WiFiMulti.cpp in order to get all APs from the APlist.

[liquidfalcon]

Additionally, Espressif's internal SDK will remember the last network it connected to (Only one, though - Never more) and automatically connect to it upon boot. You can access that stored network via WiFi.SSID() and WiFi.psk(). To disable this auto-connect, call WiFi.persistent(false)

[jumpjack]

About C++ un-knowledge.... How do I enable the DEBUG messages in WifiMulti? I see some #define but I don't know how to use them.

[liquidfalcon]

Almost all of the debugging information on the Arduino core is enabled via the "Debug Level" and "Debug Port" menus on the Arduino IDE, under tools. Choose a Debug Port, then set the Debug Level to "WiFi", and recompile.

I do believe you need to set your module to "Core Development Module" to enable the menu, however.

[jumpjack]

Do I have to set the debug port to same number of serial monitor?

[liquidfalcon]

Most likely, yes - It just spits out the debug data to whichever port you so choose. Serial is the standard RX/TX pins, and Serial1 is the secondary TX only UART

[devyte]

@jumpjack the SDK stores some info, including the wifi credentials, in a sector of the flash. That sector is kept between flashings to allow for a quick startup after update. On boot, before your sketch is executed, the SDK will retrieve the wifi credentials and attempt a quick connection.
If you change the purpose of your ESP by changing to a completely different sketch, you should wipe the flash with the esptool, and only then flash the new sketch.
Alternatively, there is an ESP.eraseConfig() call that I understand can manually wipe the relevant flash area.
Closing due to non-issue.