Handling WiFi power-save after WiFi on/off

[danalvarez]

In my application, I have turned off the WiFi power-save feature because it was causing erroneous readings in my GPIO 36 (see #4903). This worked fine before when I had the WiFi module always on, but now I am going to turn the WiFi on and off programatically.

How should I handle the power-save in this case? I had initially thought of calling WiFi.setSleep(false) after each call to WiFi.begin(), but looking at the implementation of the setSleep function, I see that it first checks if the sleepType has changed. Since in my case it never changes, setSleep only does something the very first time it is called. Each subsequent call does nothing.

Is this OK? Can I assume that the power-save configuration is mantained even after I have turned the WiFi off and back on again?

Note I am turning off the WiFi by calling WiFi.disconnect(true) and then WiFi.mode(WIFI_OFF).