ESP32 not booting until reset button pressed

[ESP_Sprite]

I'm having a similar issue than the other folks. This is the circuit of my custom board:

Remove C10.

[keithhnelson20]

Hi. I am having the same issue.

I am certain its a sleep issue, because my esp32 tried to 'execute the next program step it was in the middle of when the power went off, once usb power restored.' i.e' when the power comes back on.
The ESP32 can to a Zero-Volt Suspend and use .006 milliwatts or something insanely low, Smile at it and that's enough for hours' lol.

Therefore,
After Power-Failure, your voltage controller circuitry, needs to flash the Reset pin,
or,
like mine, the ESP32 will try and 'carry on from where it left off'
I will get back on how I did this shortly.

[djixon]

@rcoznd Your schematic is wrong. If the board is really made as design on that schematic it wont work properly. Collector of Q2 doesn't have a PLUS, ever. Also signal named as 0, on that schematic, is connected only to your switch but it should be connected to IO0 too. But even if that connection exists, Q2 can not work like that. You have to exchange collector and emitter pins on Q2 for proper operation of Q2.

[ESP_Sprite]

@rcoznd Your schematic is wrong. If the board is really made as design on that schematic it wont work properly. Collector of Q2 doesn't have a PLUS, ever. Also signal named as 0, on that schematic, is connected only to your switch but it should be connected to IO0 too. But even if that connection exists, Q2 can not work like that. You have to exchange collector and emitter pins on Q2 for proper operation of Q2.

That's actually the 'standard' auto-reset circuit as implemented on about five bazillion devboards; it's a bit weird but it works fine. Also, that schematic looks like it has the '0' net connected to IO0. Q2 specifically will pull IO0 (which has an internal pullup) low when DTR=0 and RTS=1.

[djixon]

Ah I see, there is an internal pull-up on IO0 which is always there (not need to be turned on by software) which provides PLUS on collector of Q2, that's why that transistor can work properly.

[Ron_Nachshon]

This problem is solved by removing the capacitance on io0.
Good luck.

[ChrisAlfred]

We have found that FTDI serial cables work, but CP210x cables do NOT work.
It has to do with the timing of control signals and the problem with the Q1,Q2 design I highlighted above.