This dependacy is caused by the DC-DC conversion that converts the Lipo voltage first to 5Vdc. (SY7088 chip).
The 5Vdc gets also down converted to 3v3 (SY8089 chip) .

According to the datasheet, the ESP itself should only use 0.8mA in light sleep. So 2mA gets waisted.
What a pitty.

dd.07-04-22:
The above is not completely true. I'm using the M5GFX lib and when I execute the function display.sleep(); before going to deep sleep (esp_deep_sleep_start();) the sleep current drops to a 1.25mA. Still considerable...

hmm, that is strange. I've just tried your code with the two additional lines and my M5CoreInk stays in deep sleep just fine. No fading display and counting up when GPIO36 goes high.

My guess is that maybe the battery charge in your M5CoreInk is (too) low. Have you fully charged the battery before testing?

I don't have the PIR hat so I am only testing with a wire between GPIO36 and GND or 3.3 V. Maybe the PIR hat is using too much power?

Thanks
Felix

gpio_hold_en(GPIO_NUM_12); // POWER_HOLD_PIN
gpio_deep_sleep_hold_en();

Hi Felix

This are the last commands in my setup() now - but w/o success:

  esp_sleep_enable_ext0_wakeup(GPIO_NUM_36,1); //1 = High, 0 = Low

  //Go to sleep now
  if (DEBUG) 
  {
    Serial.println("Going to sleep now");
    Serial.flush();
  }
  delay(2000);
  gpio_hold_en(GPIO_NUM_12); // POWER_HOLD_PIN
  gpio_deep_sleep_hold_en();
  esp_deep_sleep_start();

I want to wake up an M5CoreInk by EXT0 (PIR Hat).
If I connect USB counting works. If I disconnect the USB cable the display loses its contrast
Any hint is welcome.
best regards, Claus

The Display loosing contrast is because you need to set the screen HV to true before writing the frame buffer to the screen. In UIFlow there is a block for this but I have no idea about Arduino.
It sounds like the battery has not charged and so by removing the power you are killing the program.

As you are using the Arduino, you may want to look into using the ULP to handle the PIR instead of leaving it to the main cores.

try adding these two lines before going into deep sleep:

  gpio_hold_en(GPIO_NUM_12); // POWER_HOLD_PIN
  gpio_deep_sleep_hold_en();

This should keep the ESP32 powered even when going into deep sleep.

Thanks
Felix