WiFi IP issues, need WiFi::reset()

[giorgiogallina]

Dear developers,

I am having troubles in switching between WiFi's STA and AP mode on my Arduino GIGA R1 board. In my scenario, I do the following:

1. I try to connect to some network (STA)
2. If connection fails, I open AP (with random IP address) to ask credentials from user
3. Once credentials are retrieved (or on timeout, or on error), repeat from point 1.

So far I found that:

• WiFiUDP::endPacket() often fails with error -3003 (NSAPI_ERROR_PARAMETER).
• For some unknown reasons, if I call IPAddress nullip = IPAddress(); WiFi.config(nullip, nullip, nullip, nullip); before WiFi.end() before STA connection, the latter is incredibly more likely to succeed.
• However, if I do so, WiFiUDP:endPacket() always fails as above.
• I found that if I do WiFi = WiFiClass(WiFiInterface::get_default_instance()) after WiFi.end(); every time I switch between STA and AP, I have less troubles.

Before AP creation, a random IP address is set as follows:

_wifi_ap_ip = IPAddress((char)random(11, 172), (char)random(0, 255), (char)random(0, 255), 0x01);
WiFi.config(_wifi_ap_ip, _wifi_ap_ip, _wifi_ap_ip, IPAddress(255, 255, 255, 0));

I used to test my code on a protected network and I experienced fewer problems. Then I had to switch to an open network and a mess arose.

I guess a function like a total reset of the WiFi interface with sockets and everything, so to come back to a status as if the Arduino board was just switched on and no connection was attempted, would be advantageous in switching between STA and AP mode.

Thank you