ESP32 Forum

Hello everybody,

i have a problem with my ESP32 that annoys me for a long time and i can´t figure out what the problem is. My Esp32 takes messurements, which works fine. When there is not enough voltage or current, the ESP32 shuts down (which is good) and only reboots when there is enough Power (that´s the plan). And there is the problem. Sometimes it reboots perfectly and sometimes it get´s stuck and nothing happens. The code seems to be fine, I don´t think that´s the problem, because when it boots i never had probems. Did anybody have the same issue in the past or knows what could be wrong with my ESP32? My idea is to implement a watchdog that reboots the ESP32 when it get´s stuck while rebooting. But I don´t know how to implement something that can do this job:/

I´m pretty much knew to codeing so pls don´t be angry if my question isn´t clear enough, i just don´t know what information could be helpful.

Many thanks

I don't understand fully your problem.
Get it a little bit creally:
"not enough voltage or current, the ESP32 shuts down" do you use the brownout detection?

If not how do you switch off the device?

If you use the brownout detection, and you get again enough power to switch on,is the power supply can supply enough power to boot up device? You can measure with oscilloscope the power supply.

Do you have any debug message from the device?

There is a setting in menuconfig that allows you to adjust the Brownout voltage level. Have you tried playing with this?

thank you verry much everyone, i appreciate it.

chegewara that voltage supervisor looks promising and could be the reason for my problem. Especially because i use solar energy as a power supply. I will try that out, thank you verry much!

with only solar power, you can get a lot of trouble.

The solar voltage getting easily high without any load (some intensive light, or some of the cell getting some sun), and if you switch a load on it than the voltage broke down.

You need to really test the stability of the supply voltage.

It would be good to know how the hardware is designed to start with. You mentioned it's solar power only. Starting from the solar cell, where does it connect? I assume you have a power supply circuit which, among other things, provides proper regulation of voltage for the 3.3v required by the ESP32.

Hello,
i don´t think i can provide a detailed hardware picture, because it´s part of the concern i´m working in.
Basically: I got my Solar modul. On my board theres a buck converter which bring´s the voltage to 3.3 V (the solar cell brings around 35V normally). The solar modul is my only power supply, there is no extern supply. I know that solar cells often deiver high voltage while the current is close to zero. I thought in this case the ESP32 trys to start, but end´s up in brownout, because the solar modul can´t deliver enough current (=> loop of try and fail). However when there is enough current (which is the case when there is a little bit of sunlight) the ESP32 should start. But there is the Problem. Sometimes even when there is more then enough Power, the ESP32 doesn´t reboot (until i manually restart it). In some cases it works for a couple of days.

When i use a extern power supply, my application does it´s job perfectly. So i assume there is no problem with my software.

I´m open for any ideas.

What I´m trying now:
I ordered a voltage supervisor, because the ESP32 doesn´t like slowly increasing power. My buck converter should basically do the job, but maybe the voltage supervisor helps.

Basically it would be good if i have a tool which only starts my ESP when there is enough power. Something like for example 50mA and
20V at least. I don´t know if i can implement something like that and how?

Thank you verry much, let me know if there is important information missing.

I have battery powered project. What i do is detecting brownout and go to deep sleep when it occurred. Before i implemented it i had problems where esp32 eventually was in "limbo" state explained in that video. There was no way to exit it except hard reset with button (which is missing on device).
So, it is important you wont let esp32 run with low voltage and one option is voltage supervisor.

thank you, I will try that out. I´m currently waiting for my voltage supervisor.