How to Use esp32-WROOM-32e: Examples, Pinouts, and Specs

The ESP32-WROOM-32E is a powerful Wi-Fi and Bluetooth microcontroller module manufactured by Freenove. It features dual-core processing, making it ideal for a wide range of IoT (Internet of Things) applications. With its integrated antenna, low power consumption, and robust connectivity options, the ESP32-WROOM-32E is a versatile solution for projects requiring wireless communication and efficient processing.

• Smart home devices (e.g., smart lights, thermostats, and security systems)
• Industrial IoT systems for monitoring and control
• Wearable devices with wireless connectivity
• Wireless sensor networks
• Robotics and automation
• Prototyping and development of IoT solutions

The ESP32-WROOM-32E module is designed to deliver high performance while maintaining energy efficiency. Below are its key technical details:

• Processor: Dual-core Xtensa® 32-bit LX6 microprocessor
• Clock Speed: Up to 240 MHz
• Wireless Connectivity:
  • Wi-Fi: 802.11 b/g/n (2.4 GHz)
  • Bluetooth: v4.2 BR/EDR and BLE
• Flash Memory: 4 MB
• Operating Voltage: 3.0V to 3.6V
• Operating Temperature: -40°C to 85°C
• GPIO Pins: 34 (multipurpose, including ADC, DAC, PWM, I2C, SPI, UART)
• Power Consumption:
  • Deep Sleep: ~10 µA
  • Active Mode: ~240 mA (Wi-Fi active)
• Integrated Antenna: PCB antenna
• Dimensions: 18 mm x 25.5 mm x 3.1 mm

The ESP32-WROOM-32E module has a total of 38 pins. Below is a table describing the key pins:

The ESP32-WROOM-32E is a versatile module that can be used in a variety of circuits. Below are the steps and best practices for using the module effectively:

1. Power Supply: Connect the 3V3 pin to a stable 3.3V power source and GND to ground.
2. Boot Mode: To upload code, connect GPIO0 to GND and reset the module. After uploading, disconnect GPIO0 from GND.
3. Programming: Use a USB-to-serial adapter to connect the module to your computer. Connect TXD0 to the adapter's RX pin, RXD0 to the adapter's TX pin, and GND to the adapter's ground.
4. Peripherals: Connect sensors, actuators, or other peripherals to the GPIO pins as needed. Ensure the voltage levels are compatible with the ESP32's 3.3V logic.

• Voltage Levels: Avoid applying voltages higher than 3.3V to the GPIO pins to prevent damage.
• Power Supply: Use a low-noise, stable power source to ensure reliable operation.
• Antenna Placement: Ensure the integrated antenna is not obstructed by metal objects or enclosures to maintain good wireless performance.
• Deep Sleep Mode: Use deep sleep mode to conserve power in battery-powered applications.

The ESP32-WROOM-32E can be programmed using the Arduino IDE. Below is an example of how to connect the module to a Wi-Fi network:

#include <WiFi.h> // Include the Wi-Fi library for ESP32

const char* ssid = "Your_SSID";       // Replace with your Wi-Fi network name
const char* password = "Your_Password"; // Replace with your Wi-Fi password

void setup() {
  Serial.begin(115200); // Initialize serial communication at 115200 baud
  delay(1000);          // Wait for a moment to stabilize

  Serial.println("Connecting to Wi-Fi...");
  WiFi.begin(ssid, password); // Start connecting to the Wi-Fi network

  while (WiFi.status() != WL_CONNECTED) {
    delay(500); // Wait for connection
    Serial.print(".");
  }

  Serial.println("\nConnected to Wi-Fi!");
  Serial.print("IP Address: ");
  Serial.println(WiFi.localIP()); // Print the assigned IP address
}

void loop() {
  // Add your main code here
}

1. Module Not Responding:

   • Ensure the module is powered correctly (3.3V on the 3V3 pin).
   • Check the connections to the USB-to-serial adapter.
   • Verify that GPIO0 is connected to GND during programming.

2. Wi-Fi Connection Fails:

   • Double-check the SSID and password in your code.
   • Ensure the Wi-Fi network is within range and not overloaded.

3. Unstable Operation:

   • Use a stable power supply with sufficient current capacity.
   • Avoid placing the module near sources of electromagnetic interference.

• Q: Can the ESP32-WROOM-32E operate on 5V?
  A: No, the module operates on 3.3V. Applying 5V to the power or GPIO pins may damage the module.

• Q: How do I reset the module?
  A: Pull the EN pin low momentarily to reset the module.

• Q: Can I use the ESP32-WROOM-32E with the Arduino IDE?
  A: Yes, the module is fully compatible with the Arduino IDE. Install the ESP32 board package to get started.

• Q: What is the maximum range of the Wi-Fi connection?
  A: The range depends on the environment but typically extends up to 100 meters in open spaces.