ESP8684 RTC memory

[timmbo]

Hi all,

just a quick questions regarding the ESP8684H2: Does the chip have any onboard RTC memory (i.e., can memory be retained after deep sleeps)?

Thanks & Best

[ESP_Sprite]

It doesn't have dedicated memory for this. Closest you could get to this is to store data in main memory and only use light sleep. Alternatively, the ESP8685 (from the ESP32-C3 family) has 8KiB of RTC memory; you could switch to that.

[timmbo]

Thanks a lot for your answer. This is quite a surprise, making the chip basically not usable for battery operation. Are you sure on that? On

https://products.espressif.com/#/product-comparison

it says the ESP8684 has RTC SRAM of 8 KB?

Best

[ESP_Sprite]

Thanks for noticing that, that's a bug in the product comparison thing. I'll file an issue to have that looked after. The 8684 still is usable for battery operations; you'd have to save any state you'd want to save elsewhere (e.g. in NVS), though. As I mentioned before, if that is not sufficient for your use case, you can always upgrade to the 8685.