PS2: The TCP connection eventually timed out, but that was after about 30min. Is there a way to detect the client is gone faster (seconds)?

There's a clue in the message when the client eventually disconnects:

W (321422) wifi: inactive timer: now=12fede98 last_rx_time=10bab94 diff=4985e, a
id[1]10 ...

I have setup a ESP32 in softAP mode to allow just 1 client connection.

1 client connects and then establishes a tcp connection (esp32 AP is the tcp server).

Then I cut power to the wifi client (doesn't matter if the client is a computer or another esp32).

The SoftAP ESP32 will never realize the ...

There's rom_phy_get_vdd33()

I'm going to test that.

I second this, if there's a way to do this I would like to know it!