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Is it possible to disable esp32-s2's download mode?

Posted: Mon Apr 03, 2023 9:29 pm
by frotaitalos
Hi, I have a custom board with an Esp32-S2 MCU soldered right onto my pcb. In this project there is a capacitor connected to the boot pin, I got this idea from some schematics I saw on the internet and in datasheets. But what happens is that when starting the esp32 for the first time it goes directly into download mode, I need to turn off the power and power up again, I found out today that removing the capacitor on the boot pin this behavior ends, but I already have some units of this product circulating around , so I would like to know if it is possible to eliminate this behavior via modification in the bootloader.

I hope I was clear in the description above, I'm using google translate, if it wasn't clear, let me know so I can rephrase my problem

Re: Is it possible to disable esp32-s2's download mode?

Posted: Tue Apr 04, 2023 1:59 am
by ESP_Sprite
No, that is not possible. The low level on IO0 invokes the download mode in the ROM bootloader, and since that is in ROM (not flash or EEPROM), you aren't able to change that.

Re: Is it possible to disable esp32-s2's download mode?

Posted: Tue Apr 04, 2023 1:59 pm
by frotaitalos
ESP_Sprite wrote:
Tue Apr 04, 2023 1:59 am
No, that is not possible. The low level on IO0 invokes the download mode in the ROM bootloader, and since that is in ROM (not flash or EEPROM), you aren't able to change that.
Is there any way to try and fix this via custom bootloader? I already have some units of this product and a recall to remove only one capacitor would be very costly, could you confirm if this problem can be circumvented via a custom bootloader, or do I really need to do a recall?

Re: Is it possible to disable esp32-s2's download mode?

Posted: Wed Apr 05, 2023 12:20 am
by ESP_Sprite
No it is not, as I said before, the low level on IO0 makes the chip go into the (non-replacable) ROM bootloader; any custom 2nd stage bootloader will never be called. I'm afraid you'll indeed have to do a recall.