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

The ESP32 (30 pin) is a powerful microcontroller designed for IoT and embedded system applications. It features built-in Wi-Fi and Bluetooth capabilities, making it an excellent choice for projects requiring wireless communication. With its 30 GPIO pins, the ESP32 offers a wide range of input/output functions, including ADC, DAC, PWM, I2C, SPI, UART, and more. Its versatility and high performance make it a popular choice among hobbyists and professionals alike.

• IoT devices and smart home automation
• Wireless sensor networks
• Wearable technology
• Robotics and automation systems
• Data logging and remote monitoring
• Prototyping and educational projects

• Microcontroller: Tensilica Xtensa LX6 dual-core (or single-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 7-12V (via VIN pin)
• GPIO Pins: 30 (multipurpose, including ADC, DAC, PWM, etc.)
• ADC Resolution: 12-bit
• DAC Resolution: 8-bit
• Communication Protocols: UART, SPI, I2C, I2S, CAN, Ethernet
• Power Consumption: Ultra-low power consumption in deep sleep mode (~10 µA)

The ESP32 (30 pin) has the following pinout:

1. Powering the ESP32:

   • Use the VIN pin to supply 7-12V, or connect a 5V USB cable to the micro-USB port.
   • Ensure the 3.3V pin is used only for low-power external components.

2. Programming the ESP32:

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

3. Connecting Peripherals:

   • Use GPIO pins for digital input/output.
   • Use ADC pins for analog input (0-3.3V).
   • Use I2C, SPI, or UART pins for communication with sensors or other devices.

• Voltage Levels: The ESP32 operates at 3.3V. Avoid applying 5V to GPIO pins to prevent damage.
• Boot Mode: Ensure GPIO0 is pulled low during programming.
• Power Supply: Use a stable power source to avoid unexpected resets or instability.
• Deep Sleep Mode: Use deep sleep to reduce power consumption in battery-powered applications.

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

// Blink an LED connected to GPIO2 on the ESP32

#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. ESP32 Not Detected by Computer:

   • Ensure the correct USB driver is installed (e.g., CP210x or CH340).
   • Check the USB cable for data transfer capability (some cables are power-only).

2. Upload Fails with "Failed to Connect" Error:

   • Hold the "BOOT" button on the ESP32 while uploading the code.
   • Verify the correct board and port are selected in the Arduino IDE.

3. Unstable Behavior or Random Resets:

   • Use a stable power supply with sufficient current (at least 500mA).
   • Add capacitors to the power lines to filter noise.

4. Wi-Fi Connection Issues:

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

• Q: Can I use the ESP32 with 5V sensors?
  A: Yes, but you need a level shifter to convert 5V signals to 3.3V.

• Q: How do I reset the ESP32?
  A: Press the "RST" button on the board or toggle the EN pin.

• Q: Can the ESP32 run on batteries?
  A: Yes, the ESP32 can run on batteries. Use deep sleep mode to conserve power.