GPIO0 must be high on reset not to enter the bootloader mode, after booting you can use it as any GPIO. Why is it held low and how is it driving SSR, via transistor or directly? You should put a pull-up resistor on GPIO0 so that it is in high state during reset. Thanks for the reply. I'm not expert...

0,2, and 12 are the critical ones. A workaround is to put a time delay switch between the gpio and the peripheral so the bootloader can read the strapping pin before the switch connects it to the peripheral. Hello, I'd be interested in this solution. How do you put a "time delay switch"? Is it doab...

Hardware: Board: ESP32 Dev Module IDE name: Platform.io Flash Frequency: 40Mhz PSRAM enabled: no Upload Speed: 115200 Computer OS: Windows 10 Description: Hello, I have a custom made PCB developed for esp32-devkit-v4 form factory. This PCB basically has a a solid state relay controlled by the esp32...