ESP8266 Community Forum

- Mon Nov 16, 2015 3:13 am #34167 Hello all,

For a project I'm working on, I'm trying to have an ESP-07 wake up every hour.
So what I have done so far is call ESP.deepSleep and subtract micros() from the sleep interval (1h):

unsigned int sleeptime = SLEEP_INTERVAL - micros();
ESP.deepSleep(sleeptime, WAKE_NO_RFCAL);

I understand I won't get perfect accuracy but what can I expect from that ?
It doesn't seem to be that accurate

Thank you

- Mon Nov 16, 2015 5:17 pm #34230 From what i can tell the few ESPs i've tried the clock runs a little slow, so in 24 hours its slow by about 7 minutes, which i guess is about 18 seconds per hour. I don't know if thats just coincidence on the ones i've tried or that the design really is that they are all running a little slow. It also seems to take take a few hundred milliseconds to go to sleep after the deepSleep command is issued which i guess could start to add up to 7 seconds or so per day if you're doing it every hour.

What sort of accuracy are you seeing and what are you expecting?

- Mon Nov 16, 2015 7:00 pm #34237 I have projects that wake up every 1m or 5m. I run them for a day and then set a multiplier on the sleep time. I get a reasonable accuracy of a second or two per day. It seems to change slightly during the day, may be due to temperature variations.

Code: Select allsleeptime = SLEEP_INTERVAL*factor - micros()

I usually end up with a factor of around 1.02 - 1.04 - so far they are all (about 10 different ones) slow.

- Tue Nov 17, 2015 4:02 am #34283 Hello,

What value does SLEEP_INTERVAL have in your case? 3'600'000'000 ?

Even though it runs as expected, I'm wondering if batteries have an effect on that
I had better accuracy sometimes but since few days it's getting .. weird:

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