ESP32, writing and reading from NVS

ESPHome
1

I can’t find any info about writing / reading from ESP32 NVS in ESPhome, can someone help on this?

2

Well you can’t write straight to it with ESPHome but when you create some permanent variables they’ll be written in it :wink:
Why do you want to get access at NVS as such ?

3

Have a read about Global Variables.

  • restore_value (Optional, boolean): Whether to try to restore the state on boot up. Be careful: on the ESP8266, you only have a total of 96 bytes available for this! Defaults to no. This will use storage in “RTC memory”, so it won’t survive a power-cycle unless you use the esp8266_restore_from_flash option to save to flash. See esp8266_restore_from_flash for details.

On the ESP32 they just work.

4

Check out the Preferences library, which is part of the arduino-esp32 framework (part of standard esphome install). I don’t think it has a yaml interface, but its c++ API is easy to use. It stores key-value pairs to NVS.

There is also the esp32/preferences library, which I think is what esphome uses under the hood to store data across reboots. I have not worked directly with this yet.