How to Use ESP32-WROOM: Examples, Pinouts, and Specs

The ESP32-WROOM, manufactured by Freenove, is a powerful Wi-Fi and Bluetooth microcontroller module designed for a wide range of applications. It features dual-core processing, making it ideal for Internet of Things (IoT) projects, real-time data processing, and other complex tasks. With its robust wireless connectivity and versatile GPIO pins, the ESP32-WROOM is a popular choice for developers and hobbyists alike.

• IoT devices and smart home automation
• Wireless sensor networks
• Real-time data monitoring and logging
• Robotics and automation systems
• Wearable devices
• Bluetooth Low Energy (BLE) applications

The ESP32-WROOM module is packed with features that make it a versatile and powerful microcontroller. Below are its key technical specifications:

The ESP32-WROOM module has a total of 38 pins. Below is a table describing the key pins and their functions:

1. Power Supply: Ensure the module is powered with a stable 3.3V supply. Avoid exceeding the input voltage range (3.0V to 3.6V) to prevent damage.
2. Boot Mode: To upload code, connect GPIO0 to GND and reset the module. After programming, disconnect GPIO0 from GND.
3. GPIO Pins: Use the GPIO pins for interfacing with sensors, actuators, and other peripherals. Be mindful of the pin's voltage and current limits.
4. Programming: The ESP32-WROOM can be programmed using the Arduino IDE, ESP-IDF, or other compatible environments.

• Voltage Levels: The ESP32-WROOM operates at 3.3V logic levels. Use level shifters if interfacing with 5V devices.
• Deep Sleep Mode: Utilize the deep sleep mode for battery-powered applications to minimize power consumption.
• Antenna Placement: Ensure the onboard antenna has sufficient clearance from metal objects to maintain optimal wireless performance.
• Pull-Up/Down Resistors: Some GPIO pins require external pull-up or pull-down resistors for proper operation.

Below is an example of how to use the ESP32-WROOM to blink an LED connected to GPIO2:

// Example: Blink an LED using ESP32-WROOM
// Connect an LED to GPIO2 with a suitable resistor

#define LED_PIN 2  // Define GPIO2 as the LED pin

void setup() {
  pinMode(LED_PIN, OUTPUT);  // Set GPIO2 as an output pin
}

void loop() {
  digitalWrite(LED_PIN, HIGH);  // Turn the LED on
  delay(1000);                  // Wait for 1 second
  digitalWrite(LED_PIN, LOW);   // Turn the LED off
  delay(1000);                  // Wait for 1 second
}

1. Module Not Responding:

   • Ensure the module is powered correctly (3.3V supply).
   • Check the connections, especially the EN and GND pins.
   • Verify that GPIO0 is connected to GND during programming.

2. Wi-Fi Connection Fails:

   • Ensure the correct SSID and password are used in the code.
   • Check for interference or weak signal strength.

3. Code Upload Fails:

   • Verify the correct COM port and board settings in the Arduino IDE.
   • Ensure the USB cable is functional and supports data transfer.

4. Overheating:

   • Avoid exceeding the input voltage range.
   • Check for short circuits in the circuit design.

Q: Can the ESP32-WROOM be powered with 5V?
A: No, the ESP32-WROOM operates at 3.3V. Use a voltage regulator or level shifter if interfacing with 5V systems.

Q: How do I reset the module?
A: Press the EN (enable) pin or connect it momentarily to GND to reset the module.

Q: Can I use the ESP32-WROOM for Bluetooth audio streaming?
A: Yes, the ESP32-WROOM supports Bluetooth audio streaming, but additional libraries and configurations may be required.

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

This concludes the documentation for the ESP32-WROOM module. For further assistance, refer to the official Freenove documentation or community forums.