Additional power for ESP-32

This seemed to be the forum that is closest to the question I need to ask about adding an external power supply to the ESP-32.

I'm trying to connect a WaveShare 2.13" e-paper display to my ESP-32 WiFi Kit. However, when I made the connections and powered it up, the ESP-32 didn't even power up. I know this because it didn't display its start-up message to the built-in OLED display. When I disconnected the e-paper display then reconnected the USB, the ESP-32 booted up.

I'm thinking that the e-paper display takes too much power to even sit idle so the ESP-32 won't power up.

When my 3.3v/5v power supply arrives in a few days, I need to know how to hook it up. Here is what I think that I know about the ESP-32:

  1. It has both 3.3v and 5v pins. I'm thinking that the 5v is tied directly to the 5v coming in from the USB connector, and the 3.3v is the output from the ESP-32's regulator.

  2. When I connect an external power supply up to the ESP-32 I should connect the 3.3v power supply line to the 3.3v ESP-32 pin, but leave the 5v pin unconnected.

  3. Any external components using 3.3v should connect to ground, the common 3.3v line, and any data lines.

  4. Any external components using 5v should go through a level shifter.

You might want to provide a link to which 'ESP32' board you are actually using, there are quite a fes these days.

The ESP32 itself is a bare module normally, it does not have a 5V regulator.

Various manufacturers then use the ESP32 to module to build a board, they may not all have the same power arrangements.

If you got a HiLetgo ESP32, you got a sheet of paper with the ESP32. On that paper you will see, on one side a few schematics. One of the schematics will be labeled power, where you will see 5V's into a regulator and 3.3V out of the regulator.

In the case of a HiLetgo ESP32, I'd not supply the module with 3.3 volts. That will bypass the limited over voltage protection circuit.

To answer srnet, I bought this from eBay, but it is the same as this from Amazon.

To answer Idahowalker, it did not come with a schematic, just the board. However, it did have the labels for the pins, to be adhered to the header pins once they have been soldered onto the board.

So, apparently I can’t provide the 3.3v directly to the ESP-32. Can I then use a parallel power supply (that provides its own 3.3v and 5v) to provide more power to components used by the ESP-32? (See attachment.)

ESP-32-power-supply.png

Val42:
So, apparently I can't provide the 3.3v directly to the ESP-32.

That's not what he said.. he said if you do you bypass the internal extra overvolt protection, it depends how good your power supply is. (and looking at it i wouldn't worry, although if the powersupply has both 5 & 3.3v you could also power it with 5v
Can I then use a parallel power supply to provide more power to components used by the ESP-32?
[/quote]yes you can ! with the common GND as in the schematic that is fine.