NodeMCU ESP-32S Pin Configuration

There are many competing but compatible ESP32 microcontroller development boards. As a result of the competition, different ESP32 board models have different pin configurations. It is therefore imperative to properly identify your ESP32 compatible board and use the correct pin configuration guide. This NodeMCU ESP-32S pin configuration is for the ESP32 development board with the backside shown below.

NodeMCU ESP-32S backside view showing pin configuration
NodeMCU ESP-32S Backside

As can be seen from the picture above, it’s very hard to make a mistake in identifying the board if you look at the underside. It is clearly marked NodeMCU ESP-32S and at the very top of the board is a big Ai=Thinker logo.

NodeMCU ESP-32S ESP32 development board showing top side

Now, let’s take a closer look at the top side of the ESP-32S board. Take note that this particular ESP32 development board DOES NOT HAVE any pin labels on the top side. Take another look at the backside and you will find the pin labels there. If you insert this board on a breadboard, how, for God’s sake, can you see the pin labels? Start breadboarding with this ESP-32S board and you’ll know what i mean. To search for a particular pin, you will need to count the pins from either side of the board.

You would probably wish you had bought another board like this:

an image showing an alternative board DOIT ESP-32 Development Board with pin labels
DOIT ESP-32 Development Board with pin labels

Why does NodeMCU ESP-32S have no pin labels?

It is due to the board’s small form factor. The NodeMCU ESP-32S board is narrower than the DOIT ESP-32 board shown above. If pin labels were printed on the top side of the ESP-32S board, they would probably be too small to be legible.

And why, in the first place, did Ai-Thinker used a smaller form factor that prevented it from printing legible pin labels?

The reason is that the wider form factor covers the whole width of the breadboard.

A picture of a development board which is different from the NodeMCU ESP-32S pin configuration

In order to use this board having a larger form factor, you need to saw off and split your breadboard into two, like this:

A wider development board inserted on a cut breadboard
A development board on a split breadboard

In contrast, a narrower board leaves a row of breadboard pins on both sides of the board. And as a result, you don’t need to hack your breadboard.

The NodeMCU ESP-32S inserted on a breadboard showing the available breadboard points
NodeMCU ESP-32S in Breadboard showing available breadboard points
NodeMCU ESP=32S compared to a development board with a wider form factor
NodeMCU ESP-32S breadboarded with another wider board

How to Make Breadboarding NodeMCU ESP-32S Easier

As I was looking for a Fritzing part download in order to make my own pin configuration guide for NodeMCU ESP-32S, I came across this page. I am reproducing it here just in case we lost the page.

The OP (original poster) in the Fritzing forum created a pin configuration template that we can print and lay on top of the breadboard. This facilitates breadboarding, without the need to count the pins left or right when breadboarding.

Below is the edited NodeMCU ESP-32S pin configuration from the manufacturer.

NodeMCU ESP-32S Pin Configuration edited with board orientation reference
NodeMCU ESP-32S Pin Configuration Annotated with Board Orientation Reference

Related Articles

Arduino Reference and Resources

References for NodeMCU ESP-32S Pin Configuration:

ESP-32 on Wikipedia – https://en.wikipedia.org/wiki/ESP32

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