ESP32 Forum

Hi everybody, I am interested in creating a project with the esp32 wroom 32 that I want to run on battery. The end product will likely not do anything for 99% of the time but simply wait for the user to use their phone to control a door lock by communicating with the esp32 via WiFi. To my understanding, I cannot put the esp32 into any sort of sleep mode for this because any of the sleep modes turn off wifi? (I may be wrong about that). My target for battery life is 1 month, but at this point seems a little too ambitious.

So aside from reducing the clock frequency and reducing the core usage to only 1 core, is there any way that I can reduce the power consumption of the esp32 when it is just sitting and doing nothing but waiting for an action? Are there any recommendations for a certain type of battery (high capacity but low size) to use for a project like this that could also help with increasing to my target battery life? My first thought was something simple like AA Alkaline batteries but I am sure that there are better choices out there.

You might be surprised.

Try this:
https://github.com/espressif/esp-idf/tr ... power_save

With a combination of automatic light sleep, dynamic frequency scaling, and modem power saving, the ESP32 can maintain a WiFi connection while drawing as little as 3mA (with some spikes in there of course when the radio intermittently checks in with the AP). I've been very impressed in my testing.

I'd still be trying to deep sleep as much as possible, but only you know how feasible that is. If you need instant response 24/7 from anyone anywhere then it won't be possible at all. But could you deep sleep outside business hours? Deep sleep and wake on a motion sensor interrupt / capacitive touch?

boarchuz wrote: ↑

Wed Aug 28, 2019 8:02 pm

You might be surprised.

Try this:
https://github.com/espressif/esp-idf/tr ... power_save

With a combination of automatic light sleep, dynamic frequency scaling, and modem power saving, the ESP32 can maintain a WiFi connection while drawing as little as 3mA (with some spikes in there of course when the radio intermittently checks in with the AP). I've been very impressed in my testing.

I'd still be trying to deep sleep as much as possible, but only you know how feasible that is. If you need instant response 24/7 from anyone anywhere then it won't be possible at all. But could you deep sleep outside business hours? Deep sleep and wake on a motion sensor interrupt / capacitive touch?

Thank you, I will take a look! Ideally I would want it so that it could actuate a door lock whenever a user needs that to happen, so I am not sure if I could use deep sleep at all.

I have been using Arduino IDE. Do you think that learning and using IDF instead would have any power savings benefits? I have neglected using IDF because I am not using any complex "bare metal" functions and I simply already understand the Arduino IDE.

Are there any examples for the power_save code in Arduino?