Troubleshooting

Common Issues

Here are some of the most common issues around the ESP32 development using Arduino.

Note

Please consider contributing if you have found any issues with the solution here.

Here are some of the tips if The board is not flashing..

In some instances, you must keep GPIO0 LOW during the uploading process via serial interface.
Hold-down the “BOOT” button in your ESP32 board while uploading/flashing.
In some ESP32 development boards when trying to upload a new sketch, the Arduino IDE gives you a fatal error (i.e A fatal error occurred: Failed to connect to ESP32: Timed out waiting for packet header). This means your ESP32 board is not automatically in the flashing/uploading mode.

Solution:

To automatically get into the flashing mode, you have to connect a 10 uF capacitor between the EN and GND pins. This capacitor value could be lower (> 2.2 uF) if you don't have this part available. EN <----||---- GND. (The capacitor can be electrolytic, ceramic, or tantalum. Using lower values like 2.2uF and 4.7 uF is also possible in most cases.)
The hardware guide recommends adding the RC delay circuit. For more details, see the ESP32 Hardware Design Guidelines

https://www.espressif.com/sites/default/files/documentation/esp32_hardware_design_guidelines_en.pdf

in the '2.2.1 Power-on Sequence' section.