Pullup resistor for EN and BOOT Button

[kian79]

Hi all,

I am looking at all the different reference designs out there for the ESP32. And I noticed that in some of these designs, the EN and BOOT button has a pull-up resistor to VCC connected. Is this necessary?

Also, in some designs, there is a current limiting resistor between the EN pin and the push button. There is also a current limiting resistor between the IO0 and the BOOT button. Are these necessary too?

I also see capacitors connected across the push button. Some use 0.1uF and some use 1nF. So which one shold I follow?

Thanks!

[chegewara]

https://www.espressif.com/sites/default ... nes_en.pdf

[kian79]

Hi chegewara,

Thanks for sharing the link. In the PDF, I saw this line:
The EN pin is used for enabling the chip. Set the EN pin high for normal working mode. There is no RC
delay circuit on the module. It is recommended that users add an external RC delay circuit to the module.

[WiFive]

It is sort of dumb that the hardware design guidelines send you to the wroom32 datasheet, but it shows 10k pullup, 0.1uF cap on EN pin.