reconnect from Deep Sleep to AP

[behrthom]

Hi,

I have a question about the ESP32 IDF. I would like to use the ESP32 battery powerd as client at WiFi AP.
To reduce the maximum of energie i would like to switch the ESP32 in deep sleep mode. What is the fastet way to reconect the ESP32 to the AP? Is it possiple to store conections information from the last Connection to the RTC-RAM and use them after an reinit of the wifi? I have no time feeling for that, have some one infomations about the needed time from power up to send the udp or tcp/ip massage?

When will a WiFi AP diconected the Client from his AP?

kind regards
Thomas

[WiFive]

https://github.com/espressif/esp-idf/pull/3304

There is no way to restore cached wifi connection state AFAIK but you can restore dhcp state or use a static IP.

[boarchuz]

It hasn't been mentioned much for some reason but the recent IDF update has significantly improved connection speeds. It was consistently taking 1100-1300ms to connect to my home WPA2 network a couple weeks ago, but in testing this week I'm consistently getting about 500ms now (often ~400ms). I haven't tried WEP or open yet, but presumably they'd be even faster.

That is to say, give it a try first. Last week I would've been encouraging you to explore bizarre tweaks but right now I suggest you might be satisfied (or even impressed) with connection times out of the box.