Can I flash new firmware through ESP32 S3's "USB" connector?

[ugobyte]

Hello everyone,

The ESP32 S3 Dev kit has two micro USB connectors on it. One is labeled "UART" and the other is labeled "USB".
I can easily flash new firmware through the "UART" connector but not the "USB" connector. My ESP32 S3 is inside an enclosure, which means I can't reach the BOOT nor the RESET buttons.

Is it possible to flash a new firmware to the ESP32 S3 Dev kit through the "USB" connector?

[ESP_Sprite]

Yes. Note that you may want to also build in something to force the ESP32-S3 into download mode, otherwise you can get into a situation (when e.g. firmware reconfigures the USB GPIOs) when you can't use USB to force the device into download mode anymore.

[lbernstone]

https://docs.espressif.com/projects/ard ... t-printing

[ugobyte]

Yes. Note that you may want to also build in something to force the ESP32-S3 into download mode, otherwise you can get into a situation (when e.g. firmware reconfigures the USB GPIOs) when you can't use USB to force the device into download mode anymore.

Thanks. How do I force the ESP32-S3 into download mode?

[ESP_Sprite]

Thanks. How do I force the ESP32-S3 into download mode?

It's in the datasheet (section 'strapping pins'), but the short and skinny is that if you pull GPIO0 low and reset the chip, it'll come up in download mode.

[ugobyte]

Thanks. How do I force the ESP32-S3 into download mode?

It's in the datasheet (section 'strapping pins'), but the short and skinny is that if you pull GPIO0 low and reset the chip, it'll come up in download mode.

ok thanks

[ugobyte]

Thanks. How do I force the ESP32-S3 into download mode?

It's in the datasheet (section 'strapping pins'), but the short and skinny is that if you pull GPIO0 low and reset the chip, it'll come up in download mode.

Mind you, I cannot physically reach the ESP32-S3, so I have to programmatically set GPIO0 to low. Won't resetting the the chip cause GPIO0 to return to its default state after chip reset?

[ESP_Sprite]

Mind you, I cannot physically reach the ESP32-S3, so I have to programmatically set GPIO0 to low. Won't resetting the the chip cause GPIO0 to return to its default state after chip reset?

Well, you have to understand that normally, you would not need GPIO0 as when everything functions normally, you can put the chip into download mode using the USB connection. You would need the button only in extraordinary circumstances, say when you have firmware that accidentally reconfigures the GPIO pins and then hangs. So even if you could set GPIO0 in software (which you can't for the reason you indicated, but there's other ways to get the chip into download mode from software), you can't get around the fact that there still can be situations where USB alone won't work and there is no running software to get you into download mode. Situations like that don't happen very often, I've got enough hardware where I never needed GPIO0 at all, but while unlikely it's not impossible to run into them.