How to Use ESP32 (30 pin): Examples, Pinouts, and Specs

The ESP32 is a powerful microcontroller with built-in Wi-Fi and Bluetooth capabilities, making it an excellent choice for Internet of Things (IoT) applications and embedded systems. With its 30-pin configuration, the ESP32 offers a wide range of input/output (I/O) options, enabling seamless integration with sensors, actuators, and other peripherals. Its dual-core processor and low-power consumption make it suitable for both high-performance and energy-efficient designs.

• IoT devices and smart home automation
• Wireless sensor networks
• Wearable technology
• Robotics and drones
• Industrial automation
• Prototyping and educational projects

• Microcontroller: Tensilica Xtensa LX6 dual-core processor
• Clock Speed: Up to 240 MHz
• Flash Memory: 4 MB (varies by model)
• SRAM: 520 KB
• Wi-Fi: 802.11 b/g/n
• Bluetooth: v4.2 BR/EDR and BLE
• Operating Voltage: 3.3V
• Input Voltage Range: 5V (via USB) or 3.3V (via VIN pin)
• GPIO Pins: 30 pins (multipurpose)
• ADC Channels: 18 (12-bit resolution)
• DAC Channels: 2 (8-bit resolution)
• PWM Channels: 16
• I2C Interfaces: 2
• SPI Interfaces: 4
• UART Interfaces: 3
• Power Consumption: Ultra-low power in deep sleep mode (~10 µA)

The ESP32 (30-pin variant) has the following pinout:

Note: Some pins have multiple functions. Refer to the ESP32 datasheet for detailed pin multiplexing information.

1. Powering the ESP32:

   • Use the VIN pin to supply 5V or connect a USB cable to the micro-USB port.
   • Ensure the power source can provide sufficient current (at least 500 mA).

2. Connecting Peripherals:

   • Use GPIO pins for digital I/O operations.
   • For analog input, connect sensors to ADC pins (e.g., ADC1_CH0).
   • For communication, use I2C, SPI, or UART pins as needed.

3. Programming the ESP32:

   • Install the Arduino IDE and add the ESP32 board package.
   • Connect the ESP32 to your computer via USB.
   • Select the correct board and port in the Arduino IDE.
   • Write and upload your code.

• Voltage Levels: The ESP32 operates at 3.3V logic levels. Avoid connecting 5V signals directly to GPIO pins. Use a level shifter if needed.
• Boot Mode: Ensure IO0 is pulled low during programming to enter boot mode.
• Deep Sleep: Use deep sleep mode to conserve power in battery-powered applications.
• Pin Multiplexing: Be aware of pin multiplexing to avoid conflicts between peripherals.

The following example demonstrates how to blink an LED connected to GPIO2 of the ESP32:

// 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
}

Tip: Use the Serial Monitor in the Arduino IDE to debug your code and monitor outputs.

1. ESP32 Not Detected by Computer:

   • Ensure the USB cable is functional and supports data transfer.
   • Install the correct USB-to-serial driver for your operating system.

2. Upload Fails with Timeout Error:

   • Check that IO0 is pulled low during programming.
   • Press and hold the "BOOT" button while uploading the code.

3. Wi-Fi Connection Issues:

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

4. Random Resets or Instability:

   • Check the power supply for sufficient current.
   • Add capacitors to stabilize the power supply if necessary.

• Q: Can the ESP32 handle 5V logic signals?
  A: No, the ESP32 operates at 3.3V logic levels. Use a level shifter for 5V signals.

• Q: How do I use the ESP32's Bluetooth functionality?
  A: Use the BluetoothSerial library in the Arduino IDE to implement Bluetooth communication.

• Q: What is the maximum number of GPIO pins I can use?
  A: The ESP32 (30-pin variant) provides up to 30 GPIO pins, but some are shared with other functions.

• Q: How do I reduce power consumption?
  A: Use deep sleep mode and disable unused peripherals to minimize power usage.

By following this documentation, you can effectively utilize the ESP32 (30-pin) microcontroller for a wide range of applications.