How to Use ESP32-WROOM-32 (36 PIN): Examples, Pinouts, and Specs

The ESP32-WROOM-32 (36 PIN) is a powerful Wi-Fi and Bluetooth microcontroller module developed by Espressif. It is based on the ESP32 dual-core processor and is designed for a wide range of IoT applications. With its integrated wireless capabilities, extensive GPIO options, and robust processing power, the ESP32-WROOM-32 is ideal for projects requiring connectivity, real-time processing, and low power consumption.

• IoT devices and smart home automation
• Wireless sensor networks
• Wearable electronics
• Industrial automation
• Robotics and drones
• Prototyping and development of connected devices

• Manufacturer: Espressif
• Part ID: DEVKIT V1
• Processor: Dual-core Xtensa® 32-bit LX6 CPU
• Clock Speed: Up to 240 MHz
• Wireless Connectivity: Wi-Fi 802.11 b/g/n and Bluetooth v4.2 (Classic + BLE)
• Flash Memory: 4 MB (default, expandable)
• SRAM: 520 KB
• Operating Voltage: 3.3V
• Input Voltage Range: 5V (via USB) or 7-12V (via VIN pin)
• GPIO Pins: 34 (multipurpose, including ADC, DAC, PWM, I2C, SPI, UART)
• ADC Channels: 18 (12-bit resolution)
• DAC Channels: 2
• PWM Channels: 16
• Operating Temperature: -40°C to +85°C
• Dimensions: 25.5 mm x 51 mm

The ESP32-WROOM-32 (36 PIN) module features a total of 36 pins. Below is the pinout and description:

1. Powering the Module:

   • Use the VIN pin to supply 7-12V or connect a 5V USB power source.
   • Ensure the 3.3V pin is not overloaded, as it is for low-power peripherals only.

2. Programming the Module:

   • Connect the ESP32 to your computer via a USB cable.
   • Install the necessary drivers (e.g., CP2102 or CH340, depending on your board).
   • Use the Arduino IDE or Espressif's ESP-IDF for programming.

3. Connecting Peripherals:

   • Use GPIO pins for connecting sensors, actuators, or other peripherals.
   • Configure the pins in your code as input, output, or alternate functions (e.g., ADC, PWM).

4. Flashing Code:

   • Hold the BOOT button while pressing the EN button to enter programming mode.
   • Upload your code using the Arduino IDE or other compatible tools.

• Avoid applying more than 3.3V to GPIO pins to prevent damage.
• Use level shifters when interfacing with 5V devices.
• Ensure proper grounding to avoid noise and instability in the circuit.
• Use decoupling capacitors near the power pins for stable operation.

Below is an example of how to blink an LED connected to GPIO2:

// Define the GPIO pin for the LED
#define LED_PIN 2

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

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

  // Turn the LED off
  digitalWrite(LED_PIN, LOW);
  delay(1000); // Wait for 1 second
}

1. ESP32 Not Detected by Computer:

   • Ensure the correct USB drivers (CP2102 or CH340) are installed.
   • Try a different USB cable or port.

2. Code Upload Fails:

   • Check the COM port in the Arduino IDE.
   • Hold the BOOT button while pressing the EN button during upload.

3. Wi-Fi Connection Issues:

   • Verify the SSID and password in your code.
   • Ensure the router is within range and supports 2.4 GHz Wi-Fi.

4. GPIO Pin Not Working:

   • Check if the pin is configured correctly in the code.
   • Avoid using reserved pins (e.g., GPIO6-GPIO11 for flash memory).

• Q: Can the ESP32-WROOM-32 operate on battery power?

  • A: Yes, it can be powered using a LiPo battery connected to the VIN pin.

• Q: How do I reset the ESP32?

  • A: Press the RST button or pull the RST pin low.

• Q: Can I use the ESP32 with 5V logic?

  • A: No, the ESP32 operates on 3.3V logic. Use level shifters for 5V devices.