What Is ESP32-S3? Pinout, Board Variants and Getting Started

If you have built something with an ESP32 and then tried to add a camera, audio, or a color display, you have probably hit the wall: not enough pins, not enough RAM, no USB.

ESP32-S3 exists for exactly that. This guide walks through the pinout, decodes the cryptic model codes printed on the board, lists the pins you genuinely cannot use, and covers the two traps that catch people flashing their first sketch. 👇🏻

ESP32-S3 Pinout Diagram

If this is what you came for, here it is up front. The diagram below is Espressif’s official pinout for the ESP32-S3-DevKitC-1, their own reference development board:

The image is small on mobile, so tap it to zoom. If you have a different board (Waveshare, XIAO, Super Mini), the physical pin order changes but what each GPIO number does stays the same, because those functions come from the chip, not the board.

If you are cross-referencing boards, our ESP32 pinout tool covers ESP32-S3-DevKitC-1, S3-WROOM-1, C3, C6 and S2 side by side.

What Is ESP32-S3?

ESP32-S3 is the Wi-Fi + Bluetooth microcontroller Espressif introduced in 2021 as the successor to the classic ESP32.

The official spec sheet:

How is it different from the classic ESP32?

Here is the part that trips people up: ESP32-S3 is not strictly better than the classic ESP32. Things were added, and things were removed.

What that means in practice:

• If you use Bluetooth Classic, do not move to the S3. The BluetoothSerial library does not work there. Wireless headsets, SPP serial links and similar need the classic ESP32.
• There is no DAC for analog audio out. Use I2S instead, which means adding an external DAC or amplifier module such as the MAX98357A.
• Wired Ethernet needs the classic ESP32 or an external SPI Ethernet module.

What you gain in return: 11 extra pins, native USB, a camera interface, and tens of megabytes of RAM via external PSRAM.

Decoding the Model Codes: N8R8, N16R8, N32R16V

This is the single most confusing thing when buying a board. Three boards with the same name at three different prices, and these letters are why.

The code has two parts:

• N = flash memory (where your program lives), number in megabytes
• R = PSRAM (external working memory), number in megabytes
• V = the SPI bus runs at 1.8 V instead of 3.3 V

So:

What is PSRAM for? The chip’s 512 KB of internal SRAM is nowhere near enough for a camera frame or a color display framebuffer. PSRAM is an external RAM chip: megabytes of headroom, but slower than SRAM.

Module types: WROOM-1, WROOM-1U, WROOM-2

The module name at the front of the code tells you something too:

• ESP32-S3-WROOM-1: PCB antenna, quad SPI flash. The common one.
• ESP32-S3-WROOM-1U: an external antenna connector instead of the PCB antenna. Use this if the board goes inside a metal enclosure.
• ESP32-S3-WROOM-2: octal SPI memory. Faster, but it costs you pins (below).

Which Pins Can’t You Use?

The spec says 45 GPIOs, but you don’t get to use all of them freely. This is the list that breaks beginners’ projects.

1. Pins reserved for flash and PSRAM

GPIO26 through GPIO32 are wired to the internal flash and PSRAM and are not broken out. You cannot reach them anyway.

The one that matters: on parts with octal SPI memory (WROOM-2, and WROOM-1/1U with octal PSRAM), GPIO35, GPIO36 and GPIO37 are also taken by memory. The header pins are physically there, you can solder to them, and the board crashes the moment you use them.

Popular variants like N16R8 fall into this group. So on the most common board on the market, those three pins are dead.

2. Pins reserved for USB

GPIO19 = USB_D- and GPIO20 = USB_D+. If you use the native USB port, those two are occupied. By default they are also assigned to USB-JTAG debugging; reconfiguring them disables JTAG.

3. Strapping pins

Four pins decide how the board behaves at power-up:

If a circuit forces one of these HIGH or LOW at power-up, say a button with a pull-down or a relay module, the board either refuses to start or gets stuck in download mode. Once your program is running you can use them as ordinary GPIOs.

4. ADC2 conflicts with Wi-Fi

The ESP32-S3 has two ADCs:

• ADC1: GPIO1 through GPIO10
• ADC2: GPIO11 through GPIO20

Just like on the classic ESP32, ADC2 does not give reliable readings while Wi-Fi is on. If your project uses Wi-Fi and needs analog input, wire your sensors to ADC1 pins, i.e. GPIO1-GPIO10.

The pins you can actually use

On an N16R8-class board, with Wi-Fi on and the native USB port in use, what’s left safely available is:

GPIO1-GPIO18, GPIO21, GPIO38-GPIO44, GPIO47, GPIO48

Still more than the classic ESP32 offers.

The Two USB Ports: The Most Common Mistake 🔌

The DevKitC-1 has two micro-USB ports side by side, and they are not the same thing.

The beginner story is always the same: plug into the right-hand port, write Serial.println(), see nothing in the serial monitor.

void setup() {
  Serial.begin(115200);
  delay(2000);   // wait for USB to re-enumerate on the host
  Serial.println("Hello ESP32-S3");
}

If the board doesn’t show up at all: hold BOOT, press and release RESET, then release BOOT. That forces download mode and the port appears.

Getting Started with the Arduino IDE

If you don’t have the Arduino IDE yet, start with our Arduino IDE download guide.

1. Add board support. File → Preferences → Additional Board Manager URLs:

https://espressif.github.io/arduino-esp32/package_esp32_index.json

2. Install the core. Tools → Board → Boards Manager → search “esp32”, install the Espressif Systems package.

3. Pick the right board. Tools → Board → ESP32 Arduino → ESP32S3 Dev Module. If your board has its own entry (XIAO, LilyGO), choose that instead.

4. Set the options. The ones that matter:

5. Flash your first sketch. A test that drives the on-board RGB LED:

// ESP32-S3-DevKitC-1 v1.1 -> RGB LED on GPIO38
// ESP32-S3-DevKitC-1 v1.0 -> RGB LED on GPIO48
#define RGB_PIN 38

void setup() {
  Serial.begin(115200);
  delay(2000);
  Serial.printf("Flash: %u MB\n", ESP.getFlashChipSize() / (1024 * 1024));
  Serial.printf("PSRAM: %u bytes\n", ESP.getPsramSize());
}

void loop() {
  neopixelWrite(RGB_PIN, 32, 0, 0);   // red
  delay(500);
  neopixelWrite(RGB_PIN, 0, 32, 0);   // green
  delay(500);
  neopixelWrite(RGB_PIN, 0, 0, 32);   // blue
  delay(500);
}

If the serial monitor prints your flash and PSRAM sizes, the board is configured correctly. PSRAM reporting 0 means you forgot to enable it in the Tools menu.

When Should You Pick the ESP32-S3?

Pick it when:

• You are driving a color TFT or a large OLED (the LCD interface and PSRAM exist for this)
• You need a camera (the DVP interface is built in)
• You are recording or playing audio over I2S
• You want native USB (HID keyboard, MIDI device, serial)
• You are running out of pins
• You are running a small neural network on the edge

Skip it when:

• You need Bluetooth Classic (not on the S3)
• You need a DAC for analog output (not on the S3)
• You need wired Ethernet (no MAC on the S3)
• Your project just reads a sensor and posts to the cloud. An ESP32-C3 is cheaper and draws less power for that.

If displays are your thing and you need custom glyphs, our LCD character generator and image-to-C-array converter will save you time.

The Bottom Line

The ESP32-S3’s learning curve is steeper than the classic ESP32’s, but the steepness comes from choice, not difficulty: two USB ports, five module variants, a PSRAM setting you have to remember, an LED pin that moves between revisions.

Know these four things and the rest follows:

1. N and R are flash and PSRAM; don’t forget to enable PSRAM in the menu.
2. The right-hand USB port needs USB CDC On Boot enabled.
3. GPIO35-36-37 are dead on common variants, GPIO19-20 belong to USB.
4. With Wi-Fi on, read analog from ADC1, meaning GPIO1 through GPIO10.

👉🏻 When you need to look up a pin, our ESP32 pinout tool shows five boards including the S3 side by side.