Good morning everyone,
I know that waking up an ESP32 or ESP8266 can be done either by setting the RTC timer or by an external event which can be generally pushing a button. My question is can an ESP32 for example wakes up another ESP32 or ESP8266 by sending a message or a wake up signal ? of course I mean using source code. I'm working on a battery management system using duty cycling approach for my PhD and I thought I can use one ESP as controller and it will have the responsibility to wake one of the ESP slaves I should call and every slave is connected to the controller by the mean of ESP-NOW protocol or Bluetooth. Thanks in advance
I didn't find a solution from the beginning and any hint will be useful
You basically just answered your own question. The wakeup signal from one ESP device to another can just be the changing state of a GPIO pin (one device's GPIO pin connected to the other device's GPIO pin).
The sleep power when using the internal wakeup RTC is much lower (4-10uA) versus setting up a pin change to wake up (100-200uA). You will have to decide which uses less total power: