ESP32 Forum

Okay, good that you posted that schematic because if you built this, poor Q1 would have died almost immediately.
- Q1 is a BJT, and those need their base current limited. You want a series resistor of 10K or something between Vbus and the base of the transistor.
- Q1 as you have it in circuit right now will short BAT+ directly to ground. Did you intend to have a pull-up from BAT+ to EN instead of a short? If so, you forgot that again an 10K resistor will do.

poor Q1 would have died almost immediately

Yeah ahhaha poor Q1 .

Okay, good that you posted that schematic because if you built this, poor Q1 would have died almost immediately.
- Q1 is a BJT, and those need their base current limited. You want a series resistor of 10K or something between Vbus and the base of the transistor.
- Q1 as you have it in circuit right now will short BAT+ directly to ground. Did you intend to have a pull-up from BAT+ to EN instead of a short? If so, you forgot that again an 10K resistor will do.

I'm really sorry, I wanted to add the resistor but was quite late here and I forgot . I think 1k should be fine to reduce current from the battery, and 10k for the VBUS.
Updatated schematic:

That should work fine

That should work fine

So final schamatic will be this. No problems, right?
Thank you for your time.

I don't see anything obviously wrong there. I'd advise you to also check against the design guidelines one last time before you let the board fabbed as a last sanity check, but otherwise this seems good to go to me.

By the way, I was reading about the GPIO9 from:
https://docs.espressif.com/projects/esp ... ction.html
and
https://www.espressif.com/sites/default ... eet_en.pdf

And from what I understand, GPIO9 is not really really needed to upload code. It is needed only for the esptool configuration, and for a reset of the board (but without deleting the program).

In which cases is really needed? I see a lot of board the has the button to short the GPIO9 to GND, but I never used it.

It's used to force the ESP32C3 into download mode. Normally if you use the USB-serial-JTAG converter, you don't need it, as you can put the device into download mode using that. But there are ways to make the USB-serial-JTAG converter not work by accident (e.g. reconfiguring one of the GPIOs it uses), and in that case you need a way to ground GPIO9 to get back to bootloader mode. Could be a button, could be a testpad or something, could be a solder joint of a resistor, whatever makes you comfortable.