Disable wifi power saving

[genehand]

I have a decent (-67dBm) connection from the meter out in the garage, but packet loss was >90%. Once the initial setup was done it could report to MQTT, but the UI was almost unusable. Disabling the wifi power save mode completely resolves this for me. Not sure how widespread the issue is or if it's an interaction with particular AP's, I'm using a Unifi U6 Lite.

As suggested in #3122, this could be added as a configurable parameter. Understood if you'd prefer not to merge as is, in which case hopefully this is still useful to others.

• esp_wifi_get_ps
• https://github.com/espressif/esp-idf/blob/master/components/esp_wifi/include/esp_wifi_types_generic.h#L288

[genehand]

Update: Closing this out. I disabled the RSSIThreshold parameter and no longer need this fix. My ping times are somewhat slower (40-150ms vs <10ms) but the UI is nice and responsive with the default wifi power saving back on.

I didn't have this on when I first encountered the problem in 15.7.0, and must've included it when migrating to the new config options from the rolling branch.

[caco3]

It would be interesting to see the debug log when RSSIThreshold is active.
I don't really see a link between, unless your device tried to swap the AP all the time.