ESP8266 Community Forum

hello, i built a small weather station with esp, bmp 180 and dht11. I used a Samsung 18650 battery to supply the circuit. As voltage regulator I used a HT7333 to step down from 4.1v to 3.3v. I'm actually use ThingSpeak to store my data. To improve battery life i use the ESP.deepSleep(240000000); function to let the esp go to sleep for 4 minutes. While i was analysing the graphics of thingspeak i noticed that often the esp doesn't wake up every 4 minutes, but keeps sleeping for a longer time than programmed(please see attached images). Why I have this problem? maybe something wrong in the sketch or a possbile hardware problem?
thanks.

Hi, the only sure thing is that the rtc of esp8266 is not a real time clock, but just a counter; so it can have several problems. In my example i was using deep sleep for 1 hour but everytime it wakes before the hour. After several checks i use a time of 1 hour and 3 minutes instead of 1 hour. Now i've bought an external rtc (PCF8523) but i don't know how to use to wake up my esp, so i can't help you more

hi,
without the sketch we can only give educated guess ...
one would be that esp does wake up but can't connect to the internet (dsl restart, wifi blockage, router reboot,...).
I have something similar and only get dropouts when my internet is down or the battery is flat.

Please notice the date of the original post. I doubt the poster is still waiting for a reply.