ESP32-S3-WROOM-1 — Wi-Fi + Bluetooth 5 (LE) MCU Module with Vector Instructions

Overview

The ESP32-S3-WROOM-1 is a high-performance Wi-Fi and Bluetooth 5 (LE) MCU module manufactured by Espressif Systems. Built around the ESP32-S3 dual-core 32-bit Xtensa LX7 processor running at up to $240\text{ MHz}$ , it includes dedicated vector instructions designed to accelerate neural network computing and signal processing workloads (TinyML, speech recognition, face detection).

Equipped with $512\text{ KB}$ of internal SRAM, $4\text{ MB}$ to $16\text{ MB}$ of Quad/Octal SPI Flash, and up to $8\text{ MB}$ of Octal SPI PSRAM, it features a native USB 2.0 OTG Full-Speed interface, a DVP parallel camera interface, and an RGB/I8080 LCD interface. It is the dominant platform for smart displays, AI camera modules (ESP32-S3-CAM), and voice assistants.

Quick reference


CPU Core	Dual-Core 32-bit Xtensa LX7 with Vector Extensions
Max Clock Frequency	$240\text{ MHz}$
Internal SRAM	$520\text{ KB}$ ( $512\text{ KB}$ usable)
On-Module Flash	$4\text{ MB}$ , $8\text{ MB}$ , or $16\text{ MB}$ SPI Flash
On-Module PSRAM	Up to $8\text{ MB}$ Octal SPI PSRAM (N8R8 / N16R8 variants)
Operating Voltage (`VDD`)	3.0 V to 3.6 V DC (3.3 V nominal)
Wireless Support	Wi-Fi 802.11 b/g/n (2.4 GHz), Bluetooth 5.0 LE & Mesh
Camera & Display	8-bit to 16-bit DVP Camera Interface, RGB565 / I8080 LCD Driver
On-Chip USB	Native USB 2.0 OTG Full-Speed Controller
GPIO Count	36 I/O pins
Package	41-pin SMD Castellated Module ( $18 \times 25.5\text{ mm}$ ) / DevKitC-1

text

                       ┌─────────────┐
                 [GND] │ 1        44 │ [GND]
                [3.3V] │ 2        43 │ [3.3V]
               [RESET] │ 3  ESP32 42 │ [GPIO44] (U0RXD)
       (ADC1_0) [GPIO1]│ 4  -S3   41 │ [GPIO43] (U0TXD)
       (ADC1_1) [GPIO2]│ 5        40 │ [GPIO42] (MTMS)
       (ADC1_2) [GPIO3]│ 6        39 │ [GPIO41] (MTDI)
       (ADC1_3) [GPIO4]│ 7        38 │ [GPIO40] (MTDO)
       (ADC1_4) [GPIO5]│ 8        37 │ [GPIO39] (MTCK)
       (ADC1_5) [GPIO6]│ 9        36 │ [GPIO38]
       (ADC1_6) [GPIO7]│ 10       35 │ [GPIO37]
       (ADC1_7) [GPIO8]│ 11       34 │ [GPIO36]
       (ADC1_8) [GPIO9]│ 12       33 │ [GPIO35]
      (ADC1_9) [GPIO10]│ 13       32 │ [GPIO0] (BOOT Button)
               [GPIO11]│ 14       31 │ [GPIO45]
               [GPIO12]│ 15       30 │ [GPIO48] (RGB LED)
               [GPIO13]│ 16       29 │ [GPIO47]
               [GPIO14]│ 17       28 │ [GPIO21] (USB D+)
               [GPIO15]│ 18       27 │ [GPIO20] (USB D-)
                       └─────────────┘

Specifications

Parameter	Symbol	Min	Typ	Max	Unit	Conditions
Supply Voltage	$V_{DD}$	3.0	3.3	3.6	V	DC
Peak TX Current	$I_{TX\_MAX}$	—	240	355	mA	802.11b, $+20.5\text{ dBm}$
RX Current	$I_{RX}$	—	85	95	mA	Wi-Fi active
Deep Sleep Current	$I_{DS}$	—	7	20	µA	RTC memory retained
Light Sleep Current	$I_{LS}$	—	240	—	µA	CPU paused
GPIO Output Drive	$I_{IO}$	-40	—	+40	mA	Absolute max single pin

Example (Arduino ESP32 Core - Dual Core & Vector Math)

cpp

#include "esp_dsp.h"

// Onboard RGB LED on ESP32-S3-DevKitC-1 is connected to GPIO48
const int rgbLedPin = 48;

void setup() {
  Serial.begin(115200);
  pinMode(rgbLedPin, OUTPUT);

  Serial.println("ESP32-S3 Dual-Core LX7 Vector Engine Initialized!");
  Serial.printf("Free Heap: %d bytes\n", ESP.getFreeHeap());
  Serial.printf("PSRAM Size: %d bytes\n", ESP.getPsramSize());
}

void loop() {
  neopixelWrite(rgbLedPin, 0, 64, 128); // Cyan
  delay(500);
  neopixelWrite(rgbLedPin, 0, 0, 0);     // OFF
  delay(500);
}

Common mistakes

Using Octal PSRAM GPIOs (GPIO33 to GPIO37) on N8R8/N16R8 variants: ESP32-S3 modules equipped with Octal SPI Flash or Octal PSRAM (e.g. ESP32-S3-WROOM-1-N8R8) internally use GPIO33, GPIO34, GPIO35, GPIO36, and GPIO37 for high-speed PSRAM bus communication. Attempting to use these GPIOs externally breaks PSRAM access.
Boot failures due to insufficient power supply decoupling: The ESP32-S3 draws high transient current spikes ( $>350\text{ mA}$ ) during Wi-Fi transmission. Ensure the 3.3V power supply is decoupled with a low-ESR $10\ \mu\text{F}$ and $100\text{ nF}$ capacitor.

Notes

ESP32-S3 vs ESP32-WROOM-32: ESP32-S3 upgrades the CPU from Xtensa LX6 (240MHz) to LX7 (240MHz with vector instructions), upgrades Bluetooth from v4.2 to v5.0 LE, adds native USB 2.0 OTG, supports High-Speed Octal PSRAM/Flash, and adds DVP camera support.