I know there are already plenty of T/H logger projects available but I want to make it a little more advanced.
I want the ESP to store temp/humid values while it has no WIFI and upload it to a MQTT when connection is available.
The thing should also be powered by battery so Deep-Sleep will play a role. Am I right that the value (timestamp;temp;humidity) can only be stored in RTC memory? Or are there other solutions also? (no ext. storage)
If only RTC mem is possible can the whole 512 bytes of user storage can be used?
thanks for your help