ESP32 - External power supply

Thread Starter

dralsoft

Joined Oct 24, 2021
8
Hello,

I'm trying to power an ESP32 with 2 AA alcaline batteries and using a step up DC-DC (MT3608) to make it to 5V. The red led blinks all the time non stop.

This setup works for the NodeMCU ESP8266.
It also works using a simple phone charger.

Any ideas?
 

ericgibbs

Joined Jan 29, 2010
14,183
Hi,
The ESP32 Wroom PCB's I have a different pinout/layout.:(

I know that users are having problems with incorrect pin coding.

E

Update: PDF
The AZ ESP32 circuit diagram shows the Red LED is on the 5V input pin.??
If that is correct, the ESP32 current draw must be exceeding the available current from the dry battery source. You say it works OK on an external 5V supply.?
 

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Thread Starter

dralsoft

Joined Oct 24, 2021
8
Thanks for trying to fix this Eric :)

The AZ ESP32 circuit diagram shows the Red LED is on the 5V input pin.??
Yes, what the hell...? Does it make sense?

The ESP32 works ok with a 5v phone charger through USB
The NodeMCU ESP8266 works ok with my battery setup supplying 3.3v
I tried charging it with a USB cable connected to the batteries just in case, same result

So that's why I'm hitting my head agains the wall...

What is this module that is in series with the power lines.?
That's the MT3608, to boost the voltage to 5v, beacuse to AA batteries supply only 3v at best
 

ericgibbs

Joined Jan 29, 2010
14,183
Hi drai,
Bit of a puzzle.?:rolleyes:
When I configure the ESP32 types, I connect all the available Gnd/0v pins to the Common 0V line…
In theory, it should not be a problem, but worth a quick try.

E

Update:
As I said one has to be careful with ESP32 pin outs. The ESP32 pinout as posted by my colleague @bertus has an error..
GND versus CMD as per this image
EG 941.png
 
Last edited:

ericgibbs

Joined Jan 29, 2010
14,183
hi d,
Does it still run OK with USB power.?
Is there a chance your Bread board maybe defective.?

Is the ESP32 programmed with a Sketch.?
E
 

ericgibbs

Joined Jan 29, 2010
14,183
hi dra,
A long shot, but it may be poor quality pins on the ESP, check the quality with an eyeglass.
Poor finishing.?

E
BTW: I have some modules with a solder whisker between pins
 
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