How to Use ESP32D on Goouuu Expansion Board: Examples, Pinouts, and Specs

The ESP32D on Goouuu Expansion Board is a powerful and versatile development board built around the ESP32D microcontroller, manufactured by Espressif. This board integrates Wi-Fi and Bluetooth capabilities, making it an excellent choice for Internet of Things (IoT) applications. It is designed to simplify prototyping and development by providing multiple interfaces for connecting sensors, actuators, and other modules.

• IoT devices and smart home automation
• Wireless sensor networks
• Wearable technology
• Industrial automation and monitoring
• Robotics and remote control systems
• Educational projects and prototyping

The ESP32D on Goouuu Expansion Board provides a variety of pins for interfacing with external components. Below is the pinout description:

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 and connect GND to the ground.

2. Programming the ESP32D:

   • Install the Arduino IDE and add the ESP32 board support package.
   • Select "ESP32 Dev Module" as the board in the Arduino IDE.
   • Connect the board to your computer via USB and select the appropriate COM port.
   • Write or upload your code to the board.

3. Connecting Peripherals:

   • Use the GPIO pins to connect sensors, actuators, or other modules.
   • Ensure that the voltage levels of connected devices are compatible with the 3.3V logic of the ESP32D.

4. Using Wi-Fi and Bluetooth:

   • Use the built-in libraries (e.g., WiFi.h and BluetoothSerial.h) to enable wireless communication.

• Avoid supplying more than 3.3V to the GPIO pins to prevent damage to the microcontroller.
• Use level shifters if interfacing with 5V logic devices.
• Ensure proper grounding when connecting external components.
• Use decoupling capacitors to reduce noise in power supply lines.
• For battery-powered applications, consider using a voltage regulator to maintain a stable 3.3V supply.

Below is an example of using the ESP32D to connect to a Wi-Fi network and control an LED:

#include <WiFi.h> // Include the Wi-Fi library

const char* ssid = "Your_SSID";       // Replace with your Wi-Fi SSID
const char* password = "Your_Password"; // Replace with your Wi-Fi password

const int ledPin = 2; // GPIO2 is connected to the onboard LED

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

  // 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!");
  Serial.print("IP Address: ");
  Serial.println(WiFi.localIP()); // Print the device's IP address
}

void loop() {
  digitalWrite(ledPin, HIGH); // Turn the LED on
  delay(1000);                // Wait for 1 second
  digitalWrite(ledPin, 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 correct USB-to-serial driver for the ESP32D.

2. Wi-Fi connection fails:

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

3. GPIO pins not working as expected:

   • Verify that the pins are not being used for other functions (e.g., boot mode).
   • Check for short circuits or incorrect wiring.

4. Code upload fails:

   • Press and hold the "BOOT" button on the board while uploading the code.
   • Ensure the correct COM port and board type are selected in the Arduino IDE.

• Can I power the board with a battery?
  Yes, you can use a 3.7V LiPo battery with a suitable voltage regulator to provide 3.3V to the board.

• What is the maximum current output of the 3.3V pin?
  The 3.3V pin can supply up to 500mA, depending on the input power source.

• Can I use the ESP32D with other IDEs?
  Yes, the ESP32D is compatible with other development environments like PlatformIO and Espressif's ESP-IDF.

• Does the board support OTA updates?
  Yes, the ESP32D supports Over-The-Air (OTA) updates for wireless firmware uploads.