ESP32-32UE stuck in download mode on reset - urgent help needed

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MrTheRich
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Joined: Sat Sep 23, 2023 11:19 pm

ESP32-32UE stuck in download mode on reset - urgent help needed

Postby MrTheRich » Sat Sep 23, 2023 11:35 pm

I accidentally made the ESP32 be stuck in download mode everytime I press reset.

I think it happened when i wanted to use the GPIO0 button as a way to toggle network mode. I put GPIO0 as an input pin with a Pull-down. After I pressed reset, the device always starts in download mode. No matter if i reset, or disconnect and reconnect the power. I cleared and reflashed the chip multiple times now. But this change the behaviour. The chip is always automatically in download mode and i cannot reupload new code.

I am using the latest version of micropython btw. Which worked totally fine before i made this change to my code.

I'm using a cp2101 to program the chip. Which worked fine. But now I can't move on. The matter is rather urgent as this was my last spare esp32 chip, and I have a deadline Monday morning. So i need this to work..

Thanks in advance!

ESP_Sprite
Posts: 9583
Joined: Thu Nov 26, 2015 4:08 am

Re: ESP32-32UE stuck in download mode on reset - urgent help needed

Postby ESP_Sprite » Sun Sep 24, 2023 1:47 am

From what I remember, that can only happen when GPIO0 is forced low; there's nothing in firmware or anything that can make it do this. Suggest you check your hardware on that pin - possibly there's something (solder blob?) that keeps that IO pin grounded.

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MrTheRich
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Joined: Sat Sep 23, 2023 11:19 pm

Re: ESP32-32UE stuck in download mode on reset - urgent help needed

Postby MrTheRich » Sun Sep 24, 2023 8:44 am

Thank you for the reply. I did not change anything about the hardware before and after.

I remeasured the hardware just in case. The pin is not grounded so that is not the problem. But, I don't know how, the 10k pull_up smd resistor that I soldered on now only has a little 1k of resistance. I did not have any overheating of the board while testing, so I don't know how this happened. I also don't know if that is the issue, since a lower pull_up resistor should only mean a stronger pull_up signal right? Not a worse one..

EDIT: i've done some more investigating, this is what i know now:
Here is my setup
image.png
image.png (1.56 MiB) Viewed 1370 times
The problem happened after i uploaded code that put Pin 0 into internal Pull_down
I've taken off the components and tested, i've reflashed multiple times, but the behaviour stays
I've tested for shorts and there are none
and all the connections make good contact
I can overpower the 'permanent' pull_down temporarily with a 100Ohm pull_up jumper resistor. But this is not a sustainable solution.

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