ESP32 Forum

Hello Expressif members,

I am starting a new project and am in the process of choosing the devices that best meet my needs.

I want to create a system that takes pictures and stores them on an SD card autonomously when an input signal is detected (switch or presence sensor for example).

The user can download the recorded images on his smartphone using a wifi or bluetooth protocol.

The device will be powered by a battery recharged by a solar panel.

ESP32-CAM seems to be the most suitable device for my project, but a Raspberry Pi Zero can also do the job.
Indeed, the ESP32 use less power than Raspberry.
But, one of the problematic points that I noticed on the ESP32-CAM is that we have to press a button to do a reset. My system will be in a box and not accessible. Is there a way to dispense with pressing this button or doing it remotely?

In view of this small description can you tell me if the choice of ESP32-CAM is a good choice and if not what advise me

Thank you in advance,
--
GDLMDRX

....why would you have a need to manually reset the ESP32 any more than you would have a need to reset a Raspberry Pi?

Is there a way to dispense with pressing this button or doing it remotely?

Sure, tie a gpio pin to reset. From your app, you can trigger the GPIO to reset the unit.

ESP_Sprite wrote: ↑

Wed May 12, 2021 12:16 am

....why would you have a need to manually reset the ESP32 any more than you would have a need to reset a Raspberry Pi?

Thanks for this response. My system will be supply by a battery and solar panel. I tell myself that if there is not enough power in cloudy weather, a reset will be necessary. But the system will be out of range and the user will not be able to do it.

You need a voltage supervisor

Do you have a voltage supplier?

WiFive wrote: ↑

Wed Jun 02, 2021 10:49 am

You need a voltage supervisor

Thank,

I red some information on voltage supervisor and it seems to be a good idea.
If I understand well, the idea is to use les voltage supervisor to protect the esp32 against overvoltages and undervoltages and use a logical signal to reset the esp32 when the voltage is correctly stabilized ?

A voltage supervisor is typically a 3 pin device. Power, output & gnd. They come in many, many flavors. Reset voltages, and output high or output low. So lets say you picked a 2.9v threshold one like this:
https://www.digikey.com/en/products/det ... E1/4515308

When the voltage goes below 2.9v the output will go low and stay low until it gets above a certain voltage again (see data sheet).
You would tie the output to the EN pin which will hold it in a reset state if the voltage goes below 2.9v.

Are you aware that the ESP32 has a Brownout voltage detection already built in, and you can configure it for several voltage levels in menuconfig ?

https://docs.espressif.com/projects/esp ... ownout-det