I have a #Heltec "Vision Master E290" in front of me. It is way cute.
Inside is an #Espressif ESP32-S3 https://www.espressif.com/en/products/socs

I want to remember a number in a way that will survive through poweroff.

Heltec have added a battery management chip and connector. The simplest thing is to buy a teeny tiny battery. I know.

However, the ESP32 seems to have some cryptographic stores that might ?might? have some static RAM inside them? I don't know. Might???

Does anyone out there know? Is there a way to squirrel away some bits in an ESP32-S3?

#arduino #SoC #eInk

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OK, I imagined that the flash memory could only be written while the chip is in programming mode. Wrong.

The answers to my questions are:
1. Yes, not really Static RAM, it is kinda faked. More importantly, they have flash, which is always accessible.
2. ESP know how, see the 'Preferences' library: https://github.com/espressif/arduino-esp32/blob/master/libraries/Preferences
3. The code is in examples/StartCounter/StartCounter.ino

arduino-esp32/libraries/Preferences at master · espressif/arduino-esp32

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