How to Use ESP32 T-Internet-Poe: Examples, Pinouts, and Specs

The ESP32 T-Internet-PoE by LILYGO (Part ID: T-Internet-POE) is a versatile microcontroller board designed for Internet of Things (IoT) applications. It combines the powerful ESP32 microcontroller with integrated Wi-Fi and Bluetooth capabilities, making it ideal for wireless communication. Additionally, it features Power over Ethernet (PoE) support, enabling the board to receive both power and data through a single Ethernet cable. This simplifies installation, reduces wiring complexity, and makes it suitable for remote or hard-to-reach deployments.

• Smart home automation systems
• Industrial IoT (IIoT) devices
• Remote environmental monitoring
• Networked sensors and actuators
• Smart lighting and energy management
• Security and surveillance systems

Below are the key technical details of the ESP32 T-Internet-PoE:

The ESP32 T-Internet-PoE features a variety of pins for interfacing with peripherals. Below is the pinout description:

1. Powering the Board:

   • Connect the board to a PoE-enabled Ethernet switch or injector to provide both power and data.
   • Alternatively, power the board via the USB-C port using a 5V power source.

2. Connecting Peripherals:

   • Use the GPIO pins to connect sensors, actuators, or other peripherals.
   • Ensure that the logic level of connected devices is 3.3V to avoid damaging the board.

3. Programming the Board:

   • The ESP32 T-Internet-PoE can be programmed using the Arduino IDE, PlatformIO, or the ESP-IDF framework.
   • Connect the board to your computer via USB-C and select the appropriate COM port in your development environment.

4. Ethernet Configuration:

   • To use the Ethernet functionality, connect the board to a network using an Ethernet cable.
   • Configure the Ethernet settings in your code (e.g., static IP or DHCP).

• PoE Compatibility: Ensure that your Ethernet switch or injector supports IEEE 802.3af PoE standard.
• Voltage Levels: Avoid applying voltages higher than 3.3V to the GPIO pins.
• Heat Management: If the board operates in high-temperature environments, consider adding a heatsink for better thermal performance.
• Firmware Updates: Regularly update the firmware to ensure compatibility with the latest features and security patches.

Below is an example of how to configure the ESP32 T-Internet-PoE for basic Ethernet communication:

#include <ETH.h> // Include the Ethernet library for ESP32

// Define Ethernet configuration
#define ETH_CLK_MODE ETH_CLOCK_GPIO17_OUT // Set clock mode
#define ETH_PHY_POWER 12                  // GPIO pin for PHY power

// Callback function for Ethernet events
void WiFiEvent(WiFiEvent_t event) {
  switch (event) {
    case SYSTEM_EVENT_ETH_CONNECTED:
      Serial.println("Ethernet connected");
      break;
    case SYSTEM_EVENT_ETH_DISCONNECTED:
      Serial.println("Ethernet disconnected");
      break;
    case SYSTEM_EVENT_ETH_GOT_IP:
      Serial.print("IP Address: ");
      Serial.println(ETH.localIP());
      break;
    default:
      break;
  }
}

void setup() {
  Serial.begin(115200); // Initialize serial communication
  WiFi.onEvent(WiFiEvent); // Register Ethernet event callback

  // Start Ethernet
  ETH.begin(ETH_PHY_ADDR, ETH_PHY_POWER, ETH_CLK_MODE, ETH_PHY_TYPE);
  Serial.println("Ethernet initialized");
}

void loop() {
  // Main loop does nothing; Ethernet events are handled in the callback
}

1. Board Not Powering On:

   • Ensure that the PoE switch or injector is IEEE 802.3af compliant.
   • If using USB-C, verify that the power source provides at least 5V/1A.

2. Ethernet Not Working:

   • Check the Ethernet cable for damage or improper connection.
   • Verify that the network settings (e.g., IP address, subnet mask) are correctly configured in your code.

3. Wi-Fi or Bluetooth Not Connecting:

   • Ensure that the correct SSID and password are used for Wi-Fi.
   • Check for interference or weak signal strength in the deployment area.

4. GPIO Pins Not Responding:

   • Confirm that the pins are correctly configured in your code.
   • Avoid exceeding the 3.3V logic level on GPIO pins.

Q: Can I use the ESP32 T-Internet-PoE without PoE?
A: Yes, the board can be powered via the USB-C port using a 5V power source.

Q: Does the board support over-the-air (OTA) updates?
A: Yes, the ESP32 supports OTA updates, which can be implemented using the Arduino IDE or ESP-IDF.

Q: What is the maximum current output of the GPIO pins?
A: Each GPIO pin can source or sink up to 12mA. For higher currents, use external drivers or transistors.

Q: Can I use the board in outdoor environments?
A: The board is not weatherproof. For outdoor use, enclose it in a weather-resistant case.