ESP32-S2 hibernate mode + Hot Tub project

[mzakharo]

I have documented my steps enabling hibernate mode on UM Feather S2 board here:
https://forum.micropython.org/viewtopic.php?t=12378.

Continuing the discussion. I got an nRF Profiler Kit II, and my hibernate current consumption is: 34uA @ 3.3V, measured through JST connector. Also, on-board Ambient sensor increases power consumption with more light. I had to solder it off to get consistently low measurements.

As for my application: I have built a battery powered hot tub ORP & pH sensor with tflite-micro model for Free Bromine ppm estimates.

• Main Project Page
• Micropython Code

One thing I found was that pre-configuring WiFi channel when connecting to AP optimizes the power consumption further:

 wifi_sta_config.sta.channel = 11;
 esp_exceptions(esp_wifi_set_config(ESP_IF_WIFI_STA, &wifi_sta_config));

I find I can shave off 1000ms off active runtime with this setting.