Hector Martin

I tried to use an Arduino implementation. Hours of digging through the source code later because half this stuff is undocumented I'm giving up, because the design choices are fundamentally stupid and broken. Why did I even try? Seriously. Sigh.

If you're wondering: ESP8266 variant. Can't make the main thread go to sleep and wake it up on wifi events. You get to poll. Which doesn't work when you want power saving. Which I kind of do because I'm building a temperature sensor and 70mA constantly will warm it up.

It's really sad, because I implemented my entire application in 200 lines of code using all these wonderful pre-existing libraries, and now I have to rewrite it (which will probably be 2000 lines) because I hit a fundamental showstopper with power management.

I HIGHLY recommend you talk to the ESP WIZARD @cnlohr, the man works MAGIC

https://github.com/esp8266/Arduino/issues/1381 … ? any issues with this thread? Keep in mind it is only possible to enter sleep modes if you are connected to an infrastructure. APs need to _always_ be listening :(

There are two problems. One, it doesn't work properly, possibly because of bugs in the underlying esp-open-sdk. Two, even if it worked, the TCP server class is not callback-driven and requires polling from the loop thread.

I'm trying a trivial test with esp-open-sdk where I just enable light sleep and do nothing. After 10 seconds it goes into sleep briefly, I see ping latencies increase to < DTIM interval (up to 300ms), but only for a split second, then it wakes up and stays awake forever.

Keep in mind that I do *not* want to force sleep. I just want to automatically sleep when everything is idle. This is how it's supposed to work according to that power management PDF from Espressif.