boot.py not executed

[ttmetro]

boot.py and main.py are not executed on power up (or reset) after connecting an external part to the I2C bus of a HighLetgo ESP32 development board. Connecting through USB works, and I can then run boot.py manually without errors. Other than this boot issue, I2C communication works.

Does someone have insights into the powerup/boot process of the ESP32?

[b]Update 1:
[/b]Further tests reveal that it's not a power issue.
If I have anything connected to the I2C bus (e.g. INA219), boot.py and main.py will not be executed upon reset.

[b]Update 2:
[/b]Solved. See my own reply.

[ttmetro]

Solved: SDA inadvertently shared with safe boot mode --> I2C pull-ups put firmware into safe boot mode that bypasses boot.py. Changed safe boot mode to different pin.

[honestcomrade]

how did you change the safe boot mode pin?

[ttmetro]

It's set in mpconfigboard.h.

[eddo888]

for the ludites out there, how do i make it boot on external power ?

[marcidy]

microcontrollers boot when they have power, and all power is external to the microcontroller. Do you mean not using a USB cable? As long as you are properly providing power to any of the power pins, the microcontroller will start and begin execution.

There are special cases when certain pins, called strapping pins, are held in certain states during power on which changes the boot process.

It's not really clear if you are having a specific issue or just asking a general question.