Probably not relevant to grandparent if it's not battery powered, but I found the sleep modes pretty limiting on ESP8266. You can't wake from deep sleep from a

Probably not relevant to grandparent if it's not battery powered, but I found the sleep modes pretty limiting on ESP8266. You can't wake from deep sleep from a pin-change, only a timer, and you can only remember a tiny amount of data in the RTC (512 bytes), so it's essentially like a full startup from reset every time including wifi startup, which uses a lot of battery. Disclaimer: I'm pretty new to embedded stuff so I might have misunderstood.