How to Use ESP32-DevKitM-1: Examples, Pinouts, and Specs

The ESP32-DevKitM-1, manufactured by Espressif, is a compact and versatile development board built around the ESP32-MINI-1 module. It features integrated Wi-Fi and Bluetooth capabilities, making it an excellent choice for Internet of Things (IoT) applications, smart devices, and rapid prototyping. The board is designed to provide a balance of performance, power efficiency, and ease of use, catering to both beginners and experienced developers.

• IoT devices and smart home automation
• Wireless sensor networks
• Wearable electronics
• Industrial automation and control systems
• Prototyping for Wi-Fi and Bluetooth-enabled projects

The ESP32-DevKitM-1 is equipped with the ESP32-MINI-1 module, which is based on the ESP32 chip. Below are the key technical details:

• Processor: Dual-core Xtensa® 32-bit LX6 microprocessor
• Clock Speed: Up to 240 MHz
• Wireless Connectivity:
  • Wi-Fi: 802.11 b/g/n (2.4 GHz)
  • Bluetooth: v4.2 BR/EDR and BLE
• Flash Memory: 4 MB (embedded in the ESP32-MINI-1 module)
• Operating Voltage: 3.3V
• GPIO Pins: 20 (multipurpose, including ADC, DAC, PWM, I2C, SPI, UART)
• Power Supply: USB or external 5V
• Dimensions: 48.3 mm x 25.5 mm

The ESP32-DevKitM-1 features a 20-pin layout. Below is the pin configuration:

1. Powering the Board:

   • Connect the board to a computer or USB power source using a micro-USB cable.
   • Alternatively, supply 5V to the VIN pin for external power.

2. Programming the Board:

   • Install the Arduino IDE or Espressif's ESP-IDF development framework.
   • Add the ESP32 board support package to the Arduino IDE via the Boards Manager.
   • Select "ESP32 Dev Module" as the board type in the IDE.

3. Connecting Peripherals:

   • Use the GPIO pins to connect sensors, actuators, or other peripherals.
   • Ensure that the voltage levels of connected devices are compatible with the 3.3V logic of the ESP32.

4. Uploading Code:

   • Write your program in the Arduino IDE or ESP-IDF.
   • Connect the board to your computer via USB and select the appropriate COM port.
   • Press the "Upload" button in the IDE to flash the code to the board.

• Voltage Levels: The GPIO pins operate at 3.3V. Avoid connecting 5V signals directly to the pins to prevent damage.
• Boot Mode: To enter bootloader mode, hold down the IO0 button while pressing the EN button.
• Power Supply: Use a stable power source to avoid unexpected resets or performance issues.
• Antenna Placement: Ensure that the onboard antenna has sufficient clearance from metal objects to maintain optimal wireless performance.

Below is an example of using the ESP32-DevKitM-1 to control an LED via Wi-Fi:

#include <WiFi.h>

// Replace with your network credentials
const char* ssid = "Your_SSID";
const char* password = "Your_PASSWORD";

void setup() {
  Serial.begin(115200); // Initialize serial communication
  pinMode(2, OUTPUT);   // Set GPIO2 as an output pin (connected to an LED)

  // Connect to Wi-Fi
  Serial.print("Connecting to Wi-Fi");
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("\nWi-Fi connected!");
}

void loop() {
  digitalWrite(2, HIGH); // Turn the LED on
  delay(1000);           // Wait for 1 second
  digitalWrite(2, LOW);  // Turn the LED off
  delay(1000);           // Wait for 1 second
}

1. The board is not detected by the computer:

   • Ensure the USB cable is functional and supports data transfer.
   • Install the required USB-to-serial driver for the ESP32.

2. Code upload fails:

   • Check that the correct COM port is selected in the IDE.
   • Hold down the IO0 button while pressing the EN button to enter bootloader mode.

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. GPIO pin not working as expected:

   • Confirm that the pin is not being used for another function (e.g., boot mode).
   • Check for short circuits or incorrect wiring.

• Can the ESP32-DevKitM-1 operate on battery power? Yes, you can power the board using a 3.7V LiPo battery connected to the 3V3 pin, but ensure proper regulation.

• What is the maximum current output of the GPIO pins? Each GPIO pin can source or sink up to 12 mA safely.

• Is the ESP32-DevKitM-1 compatible with Arduino libraries? Yes, most Arduino libraries are compatible with the ESP32, but some may require modifications.

This concludes the documentation for the ESP32-DevKitM-1. For further details, refer to the official Espressif documentation.