LILYGO T-Internet-POE V2 ESP32 Ethernet Board with PoE & Downloader

Specifications

• Microcontroller: ESP32-WROOM (Dual-core, 240 MHz)

• Ethernet Transceiver: LAN8720A

• PoE Controller: Si3404 (IEEE 802.3af compliant)

• PoE Input Voltage: 36V ~ 57V DC

• Flash Memory: 4MB

• Wireless: Wi-Fi (802.11 b/g/n) & Bluetooth 4.2 (BLE)

• Storage: Integrated MicroSD (TF) Card Slot

• Programming Interface: CH340C USB-C Downloader Board (Included)

• Dimensions (Main Board): 70mm (L) x 52.3mm (W) x 17mm (H)

Key Applications and Projects

• ESPHome Bluetooth Proxies: Hardwiring an ESP32 to your network and placing it centrally in your home to forward Bluetooth Low Energy (BLE) packets from smart thermometers directly to Home Assistant.

• Industrial Sensor Gateways: Polling Modbus or I2C sensors in a factory environment and reliably pushing the telemetry data to a local server without Wi-Fi interference.

• Off-Grid Security Loggers: Powering an RFID scanner or access control keypad via a single PoE cable pulled from a secure server room switch.

Unlock New Capabilities (Project Evolution) The Ultimate Garage Access Controller: Wi-Fi rarely reaches the detached garage reliably. Evolve your smart home setup by running a single burial-grade Cat6 Ethernet cable from your home router out to your garage. Plug the T-Internet-POE into a PoE switch inside your house. Out in the garage, the board now has rock-solid power and data. Program the ESP32 to control a relay that opens your garage door. Because the board has Bluetooth 4.2, you can also program it to detect the BLE MAC address of your car or smartphone, creating an ultra-reliable, hardwired auto-opening smart garage system!

PACKAGE INCLUDED

• 1 x LILYGO T-Internet-POE V2 Main Board

• 1 x Downloader Expansion Board (CH340C USB-C)

• 1 x Double-Row Male Pin Header (Unsoldered)

Downloads & Links

• LilyGO-T-ETH-Series Github Link

FREQUENTLY ASKED QUESTIONS (FAQ)

1. What microcontroller drives this board? It is powered by the Espressif ESP32-WROOM module.

2. What is PoE and why is it useful? PoE stands for Power-over-Ethernet. It allows standard Ethernet networking cables to carry electrical power alongside data. This lets you install devices in locations where it is difficult or expensive to install traditional electrical outlets.

3. What standard of PoE does this board support? It uses an Si3404 PD chip that complies with the active IEEE 802.3af standard, safely accepting 48V (36V-57V range) from standard PoE switches or injectors.

4. Can I power it via USB instead of PoE? Yes. You can provide 5V power to the board using the USB Type-C port on the Downloader expansion board. Do not power it via USB and PoE simultaneously.

5. Does this board have PSRAM? No. The standard ESP32-WROOM module installed on this board does not feature external PSRAM. It utilizes the standard 520 KB of internal SRAM.

6. Why is the "Downloader" a separate board? To keep the main PoE board small and reduce heat/cost for permanent deployments, the USB-to-Serial chip (CH340C) was removed. You only plug the Downloader board in when you need to flash new firmware.

7. How do I attach the Downloader board? The Downloader board plugs into the proprietary double-row pin header on the bottom side of the T-Internet-POE board. Make sure the pins align correctly before applying power.

8. Can I use the MicroSD card slot and flash firmware at the same time? Generally, no. The MicroSD card slot shares several SPI pins (like MISO/MOSI) with the firmware flashing lines. You must usually remove the MicroSD card to successfully upload a new sketch via the Downloader.

9. Does the board still support Wi-Fi and Bluetooth? Yes. Despite having Ethernet, the ESP32 still features its standard 2.4 GHz Wi-Fi and Bluetooth 4.2 (BLE) radios. You can actually use both interfaces simultaneously (e.g., using Ethernet for WAN and BLE for sensor scanning).

10. What Ethernet chip is used? The board utilizes the LAN8720A Ethernet physical layer transceiver (PHY).

11. What settings do I need in ESPHome to make the Ethernet work? In your YAML configuration, you must define the ethernet component, set the type to LAN8720, set the mdc_pin and mdio_pin to their mapped values, and critically, set the clk_mode to GPIO17_OUT (or GPIO0_IN depending on the exact board revision—check the official LILYGO documentation).

12. Do I need to solder anything? The main components and RJ45 jack are pre-soldered. The kit comes with an extra block of male header pins that you must solder yourself if you wish to use the general-purpose GPIO pins on a breadboard.

13. What are the exact dimensions of the board? The main board (excluding the Downloader) measures 70mm in length, 52.3mm in width, and 17mm in height.

14. What logic voltage do the GPIO pins use? Like all ESP32 microcontrollers, the GPIO pins operate strictly on 3.3V logic. Supplying 5V directly to a logic pin will destroy the chip.

15. Is there an RTC (Real-Time Clock) on this board? No, there is no dedicated RTC chip or coin cell battery backup on the T-Internet-POE. You should pull time data via NTP over the network connection.

16. Are there any physical buttons? Yes, the board features a Boot button (IO0) and a Reset button, allowing you to manually enter download mode if the auto-reset circuit on the Downloader fails.

17. How do I program this with the Arduino IDE? Connect the Downloader board, plug in a USB-C cable, and select "ESP32 Dev Module" from the board manager. Select the COM port associated with the CH340C chip.

18. What do the pins on the expansion header do? The double-row pin header breaks out various ESP32 GPIOs, 3.3V, 5V, and GND. Note that many pins on the ESP32 are already consumed by the Ethernet MAC, reducing the number of free pins available for user projects.

19. My network switch doesn't provide PoE. How can I power this? You will need to purchase an inexpensive "PoE Injector" (802.3af compliant). This small device sits between your non-PoE switch and the T-Internet-POE, injecting the required 48V into the Ethernet cable.

20. Will the PoE generate heat? Yes, stepping down 48V to 5V will generate warmth on the Si3404 chip. Ensure your 3D printed enclosures have adequate ventilation to prevent the ESP32 from thermal throttling.