I am trying my ESP32-CAM for project but I am having problems with uploading script/code to the ESP. I am using CP2102 to connect ESP and my laptop. I tried connecting it to 3.3V and even 5V but none seem to be working as I always get the same error: "A fatal error occurred: Failed to connect to ESP32: Timed out waiting for packet header"

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  • 3
    Did you connect GPIO0 to Ground when powering up the ESP32Cam, before starting the upload?
    – StarCat
    Sep 16, 2021 at 18:14
  • Yes, I connected it exactly like this : i1.wp.com/randomnerdtutorials.com/wp-content/uploads/2019/12/… Don't know if it helps but when I connected it of the two LEDs on this USB-UART (TXD and RXT) only TXD was blinking.
    – Dionyz
    Sep 17, 2021 at 15:08
  • i bet the 3.3v isn't strong enough to power the ESP32
    – dandavis
    Sep 17, 2021 at 21:02
  • Well as I said, I tried 5V too, meanwhile I tried using Arduino Mega as "programmer" so I could be sure it isn't in UART-USB and it did the same thing. I am wondering if the ESP isn't damaged, any ideas how to test it?
    – Dionyz
    Sep 18, 2021 at 14:38

1 Answer 1


For future references.

So after some time I was finally able to upload my code into ESP32-CAM. I don't know if I had just bad luck with "faulty" ESP but here is what helped me.

  1. Don't use CP2102, it just doesn't work for me, use other programmer or Arduino as I did.

  2. If you have been using scheme like this scheme and wasn't able to fix your problem try to connect all other things that need GND on some breadboard and use just one GND pin from ESP. I noticed that GNDs on ESP has (or atleast mine have ) 0.5V difference between them. Right now I am using the GND pin that was connected to IO0 as "main" GND and its works.

Hope this helps someone and thanks for all replies.

  • Thanks for posting your solution. Please note that whatever your problem was, it might very well come down to power supply issues. In my experience, not all commonly available USB Serial->TTL converters are powerful enough for an ESP32Cam (either at 3.3V or 5V), especially once the ESP32 is starting up, connecting to Wifi and powering up its camera.
    – StarCat
    Sep 26, 2021 at 8:21

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