Many Thanks! You were right. The repeated initialization makes problems.
I wouldn't have thought of that.

Boarchuz, you are my hero!

For posterity... I solved the problem like this. If there are better solutions, they are very welcome!


#include <Arduino.h>
#include <SPI.h>
#include <stdio.h ...

Hello, everyone

I'm working on a project to read an I2C sensor with an ESP32 in battery mode.
For this, I want to use the I2C bus with the ULP Coprocessor in the deep sleep mode.

This should be possible and is even advertised:
"The Ultra Low Power (ULP) coprocessor is a simple finite state machine ...