ESP8266 Community Forum

- Wed May 09, 2018 4:44 am #75842

i need RTC to be running

In deep-sleep mode the RTC is running. Actually it's the only running part. https://www.espressif.com/sites/default ... s_en_0.pdf

- Wed May 09, 2018 6:59 am #75844 I know my earlier reply wasn't very useful and that's partly because in the time since I started using esp8266 (since 2015) I have seen very little information on light sleep. If you are serious about having very low power use, I would highly recommend moving over to esp32; it appears to have much better (flexible, lower power) sleep modes (it has a low power co-processor [ULP] too with an RTC) and I seem to recall good documents (when I looked a while back). Given that an esp32 is now less than £4 ($5 ish) I think you will save a lot of time and have a better product at the end. When I finally move onto portable low power projects I will not be using esp8266 that is for sure.

- Wed May 09, 2018 8:16 am #75845 While the ESP32 offers lots of advantages, I think there is still a place for the 8266 in low power applications. Where processing power and GPIO is adequate then the lower cost and easier connections still offer some plus points.

For example, one can use the ENABLE as the start signal from things like magnetic door switches to let the device run, signal and then shutdown waiting for the next trigger. Same goes for other sensors which can generate a suitable trigger like a PIR.

The timed mechanism using GPIO16 also works OK.

- Wed May 09, 2018 10:34 am #75847

While the ESP32 offers lots of advantages, I think there is still a place for the 8266 in low power applications. Where processing power and GPIO is adequate then the lower cost and easier connections still offer some plus points.

For example, one can use the ENABLE as the start signal from things like magnetic door switches to let the device run, signal and then shutdown waiting for the next trigger. Same goes for other sensors which can generate a suitable trigger like a PIR.

The timed mechanism using GPIO16 also works OK.

I'm disappointed with myself that I haven't had the time to look into the whole thing to offer any proper advice on this. I guess I'm just 'impressed' with the obvious effort Espressif has gone into with the low-power ULP/RTC/RAM (not that I've actually used it!).
I wonder; are there any comparisons written-up on low-power usage with the two different chips (pros/cons etc)? Not that I want to derail this thread, sorry!