Failed to connect ESP32: Timed out waiting for packet header

1st March 2019 Harshvardhan Mishra

In the post i am telling to you “Failed to connect ESP32: Timed out waiting for packet header” error when trying to upload new code to your ESP32 board once for all.

Why you’re getting this error?T

Many ESP32 development boards don’t go into flashing/uploading mode automatically when uploading a new code. When you try to upload a new sketch to your ESP32, the Arduino IDE fails to connect to your board, and you get the following error message:

Simplest ways to solve this is holding-down the “BOOT” button in your ESP32 board while uploading a new sketch at the same time. But having to worry about this every time you want to upload new code can be tedious, specially when you’re testing and debugging your code. There is a way to fix this once for all – no need to hold down the “BOOT” button anymore.

Failed to connect ESP32: Timed out waiting for packet header [SOLVED]

How to fix the Error?

If you want To make your ESP32 board go into flashing/uploading mode automatically. You can connect a 10 uF electrolytic capacitor between the EN pin and GND. I have ESP WROOM 32.

Please check first this setup with breadboard to make sure it works for your ESP32 development board.

Note: electrolytic capacitors have polarity. The white/grey stripe indicates the negative lead.

If it works, then you can solder the 10 uF electrolytic capacitor to the your board. Since the EN and GND pins are far apart from each other, you can simply connect the capacitor between the EN and the GND of the ESP32 chip as shown in the schematic diagram below:

Given below figure shows how my ESP32 looks like after soldering the capacitor.

Before trying to upload a new code, you should check the connections with a multimeter in continuity mode – check that you haven’t inadvertently solder anything to the next pin.

If everything is soldered properly, you won’t need to press the BOOT button when uploading new code. You also won’t get the “Failed to connect to ESP32: Timed out waiting for packet header” error.