How to Use ESP32 - 38 pins: Examples, Pinouts, and Specs

The ESP32 is a versatile and powerful microcontroller with integrated Wi-Fi and Bluetooth capabilities. It is widely used in Internet of Things (IoT) applications, smart home devices, and for prototyping wireless communication projects. The 38-pin variant provides ample GPIO pins for interfacing with a variety of sensors, actuators, and displays.

• Smart home devices (e.g., light switches, thermostats)
• IoT sensor nodes
• Wearable electronics
• Wireless communication systems
• Robotics

• Microcontroller: Tensilica Xtensa® Dual-Core 32-bit LX6
• Operating Voltage: 3.3V
• Input Voltage (recommended): 5V
• Input Voltage (limit): 6-12V
• Digital I/O Pins: 34 (of which 12 can be configured as PWM outputs)
• Analog Input Pins: 18
• Analog Output Pins: 2 (DAC)
• Flash Memory: 4MB
• SRAM: 520 KB
• Clock Speed: 240 MHz
• Wi-Fi: 802.11 b/g/n
• Bluetooth: v4.2 BR/EDR and BLE

1. Powering the ESP32: Connect a 5V power supply to the 5V and GND pins. Alternatively, you can use a 3.3V supply directly to the 3V3 pin.
2. Programming the ESP32: Use a micro USB cable to connect the ESP32 to your computer. Install the necessary drivers and use the Arduino IDE or ESP-IDF for programming.
3. Connecting I/O Devices: Interface sensors, actuators, or other peripherals to the GPIO pins. Ensure that the voltage levels are compatible with the ESP32's 3.3V logic.

• Always check the power requirements of peripherals to avoid damaging the ESP32.
• Use a logic level converter if interfacing with 5V devices.
• Avoid using IO9 and IO10 as they are not exposed in all modules.
• IO34 and IO35 cannot be used as digital outputs.
• When using Wi-Fi or Bluetooth, ensure that the antenna area is not obstructed.

• ESP32 not booting: Ensure that the boot mode is correctly set by checking the IO0 pin.
• Wi-Fi/Bluetooth not functioning: Verify that the antenna is not obstructed and that the correct drivers are installed.
• Unexpected resets: Check the power supply for stability and sufficient current.

• Use a multimeter to check the voltage levels at different points in the circuit.
• Ensure that the GPIO pins are configured correctly in your code.
• Consult the ESP32 datasheet for detailed information on pin functions and limitations.

#include <WiFi.h>

// Replace with your network credentials
const char* ssid = "your_SSID";
const char* password = "your_PASSWORD";

void setup() {
  Serial.begin(115200);
  
  // Connect to Wi-Fi
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.println("Connecting to WiFi...");
  }
  Serial.println("Connected to WiFi");
}

void loop() {
  // Your code here
}

• #include <WiFi.h>: Include the Wi-Fi library for ESP32.
• const char* ssid: Replace your_SSID with your Wi-Fi network name.
• const char* password: Replace your_PASSWORD with your Wi-Fi network password.
• Serial.begin(115200): Initialize serial communication at 115200 baud rate.
• WiFi.begin(ssid, password): Start Wi-Fi connection with SSID and password.
• WiFi.status(): Check the status of the Wi-Fi connection.
• Serial.println(): Print messages to the serial monitor.

Remember to adjust the SSID and password to match your Wi-Fi network's credentials before uploading the code to the ESP32.