ESP32-WROOM bare module boot-up problem

[davefes]

To be able to cram more functionality into little boxes I have started using
ESP32 bare module boards
https://www.aliexpress.com/item/32961594602.html?spm=a2g0o.order_list.order_list_main.47.21ef1802fCt7L2

But, every time I build another project I struggle to get them to boot-up
reliably. Sometimes holding the EN line low for longer periods seems to help, but
then sometimes it doesn't. The only thing that seems to work every time is after
applying power, say for more than 1 sec, is to then pull the enable line low for
a short period and then release it.

Having a switch to turn the 3V3 on/off and then another button to EN the chip does not
seem end-user friendly.

In reading through esp32-wroom-32_datasheet_en.pdf focusing-on CHIP_PU Table 4, page 20
I don't see anything complicated ... they just say hold EN (CHIP_PU) low for >50us after
applying chip power (3V3).

I keep looking for something special on the ESP32-DevKitc_V4 schematic and I worry about
that transistor-pair that toggles the EN and Boot (IO0) under control from the CP2102. Is
that doing something important. I have been able to cut power to the CP2102 on several projects
and still get them to boot ... but maybe I was just lucky.

Does anyone have any bullet-proof boot-up circuit recommendations?

Thank you.

BTW, Re comments about large caps on 3V3. I have noticed that if you put a chip
into deepsleep, remove 3V3 that this line stays high for a long time, maybe not
what you what.

[davefes]

Well, it seems that you need to pull-up GPIO0 to run the program as well as to flash the Micropython image. I guess that is the main reason for that transistor-pair on the DevKitc boards.