ESP32 Forum

Hi everyone,

I have a ESP32-WROOM-32 which I connected to a external GC9A01 display screen (https://www.waveshare.com/1.28inch-lcd-module.htm). The display is using the 3.3V pin.

When I plug my ESP32 on the USB input it starts well and display the information I need on the display screen, so everything works fine and as expected.

Now I'm trying to use a 3.7V 2.4Wh lithium battery with a step up module (MT3608) to start it, instead of using the USB power directly from the ESP32. If I use a multimeter on the output VOUT of the step up module I see 3.4V which falls within the range that ESP32 can operate (2.2 to 3.6V according to the web). On the ESP32 I'm using VIN (+) and GND (-) but for some reason my ESP32 does not turn on. ore information on the attached picture.

Any ideas of what might be happening? I'm new to hardware (coming from software development) sorry if I'm not detaling enough my problem.

Thanks in advance,
Caio

Hi,
The vin pin will be expecting 5v (i.e. the power from the usb socket)
the 3.3v pin on the other side is the power going to the esp32 module

alanesq wrote: ↑

Fri Mar 04, 2022 8:04 am

Hi,
The vin pin will be expecting 5v (i.e. the power from the usb socket)
the 3.3v pin on the other side is the power going to the esp32 module

Does it mean that I must have 5V in my battery and connect that to the VIN to make it work?
Because I read that the operating voltage of ESP32 is up to 3.6V I thought I could burn it if I'm using 5V, isn't that the case?

Thanks!

You can supply 3.3V directly to the 3.3V pin bypassing the built-in voltage regulator, but make sure it's not above 3.6v (max allowed voltage according to spec)

I am having a problem related to this.
The Esp32 dev board has code that runs when I connect it using micro USB, works fine when esp32 dev board connected using 5v adaptor, works fine when connected using 3.7v battery using XL6009 to convert 3.7v to 5v.
The code doesn't work when connected with battery using mt3608 to convert to 5v. I replaced old mt3608 board with the new mt3608. Still did not work.
All the above connection done to 5v input to regulator of the board. One catch is I am using mpu6050 module instead of display.