OLIMEX ESP32-POE and ESP32-POE-ISO User Manual

Revision 1.0 May 2023

www.olimex.com

Introduction to ESP32-POE

The ESP32-PoE is an IoT development board based on the ESP32-WROOM-32E module, featuring Wi-Fi, Bluetooth, Ethernet, and Power-Over-Ethernet (PoE) capabilities. The PoE functionality is managed by a TPS2375/6 chip (Si3402-B in older revisions), compliant with the IEEE 802.3af standard, including legacy PoE support. Successful PoE operation requires a minimum of 37V DC. The board draws power from the Ethernet cable and can be expanded with sensors and actuators, making it a suitable solution for Internet-of-Things projects.

⚠️ Important Notice: The ESP32-PoE lacks galvanic isolation from its Ethernet power supply. When programming the board via the micro USB connector, the Ethernet cable should be disconnected if it is powered by PoE. This prevents accidental short circuits that could damage the computer and the board, and may void the warranty. For isolation, consider using the Olimex USB-ISO or the Olimex ESP32-PoE-ISO board.

The ESP32-POE-EA variant includes the ESP32-WROOM-32UE module with a U.FL connector and an external antenna. The ESP32-POE-IND and ESP32-POE-EA-IND models use industrial-grade components, rated for operating temperatures between -40°C and +85°C.

The ESP32-POE-WROVER model is equipped with an ESP32-WROVER-E module, featuring 4MB of flash memory and 8MB of PSRAM. The ESP32-POE-WROVER-EA uses an ESP32-WROVER-IE module, also with a U.FL connector and an external antenna.

ESP32-POE Features

ESP32-WROOM-32E Espressif Inc Wi-Fi + Bluetooth (Bluetooth) LE module with 4MB Flash and 520 KB SRAM
High-reliability industrial grade (-40 to +85°C) available (-IND)
CE-RED and LVD certification
Original design by OLIMEX Ltd
Power Over Ethernet negotiation circuit 802.3 compliant, with a minimum operating voltage of 35VDC
DC-DC converter with 5V 3A output
LiPo battery charger
LiPo battery connector
Battery level monitor pin on ADC
External power supply detection pin on ADC
UEXT connector
User button
Reset button
Micro USB connector for ESP32 programming
MicroSD card slot
Two extension connectors, 0.1" pitch, spaced at 1"
PCB dimensions: (80 x 28)mm ~ (3.15 x 1.1)"

ESP32-POE-ISO Features

ESP32-WROOM-32E Espressif Inc Wi-Fi + Bluetooth (Bluetooth) LE module with 4MB Flash and 520 KB SRAM
Power Over Ethernet negotiation circuit 802.3 compliant, with a minimum operating voltage of 35VDC
High-reliability industrial grade (-40 to +85°C) available (-IND)
CE-RED and LVD certification
Original design by OLIMEX Ltd
Low power design: 200µA consumption in deep sleep
Ethernet 100Mb interface with IEEE 802.3 PoE support
3000VDC galvanic insulation between the PoE Ethernet part and the board's power supply circuit
Micro USB connector for ESP32 programming
MicroSD card working in 1 bit mode
LiPo battery charger with LiPo battery connector
Battery level monitor pin on ADC
External power supply detection pin on ADC
DC-DC 2W 5V/400mA
UEXT connector
User button
Reset button
Two extension connectors, 0.1" pitch, spaced at 1"
PCB dimensions: (98 x 28)mm ~ (3.8 x 1)"

PoE Standard

The ESP32-POE and ESP32-POE-ISO boards adhere to the IEEE 802.3af PoE standard, providing up to 15.4 W of DC power (minimum 44 V DC and 350 mA). Approximately 12.95 W is available at the powered device, accounting for power dissipation in the cable. The ESP32-POE-ISO features a 2W DC-DC 5V-5V insulation converter, limiting its power usage to 2W.

Differences Between Models

ESP32-POE vs. ESP32-POE-ISO

The ESP32-POE is not galvanically isolated, making it unsafe to connect to devices using non-isolated power supplies. Connecting the ESP32-POE to a computer's USB port while it is powered via Ethernet PoE can damage the board, the computer, or both, and will void the warranty. In contrast, the ESP32-POE-ISO provides 3000VDC galvanic insulation between the Ethernet PoE circuitry and the ESP32's power supply, allowing safe USB connection for programming and debugging even when connected to Ethernet PoE.

ESP32-POE vs. ESP32-POE-WROVER

The standard ESP32-POE utilizes an ESP32-WROOM-32E module with 4MB Flash and 520KB RAM. The ESP32-POE-WROVER is equipped with an ESP32-WROVER-E module, offering 4MB Flash and 8MB PSRAM. The WROVER module requires two GPIO pins for PSRAM connectivity, rendering those pins unavailable for general use.

Order Codes and Accessories

ESP32-POE and Accessories

ESP32-POE: Commercial grade 0-70°C board with internal antenna.
ESP32-POE-EA: Commercial grade 0-70°C board with external antenna.
ESP32-POE-IND: Industrial grade -40 to +85°C board with internal antenna.
ESP32-POE-EA-IND: Industrial grade -40 to +85°C board with external antenna.
ESP32-POE-WROVER: Commercial grade 0-70°C board with 8MB PSRAM and internal antenna.
ESP32-POE-WROVER-EA: Commercial grade 0-70°C board with 8MB PSRAM and external antenna.
BATTERY-LIPO1400mAh: LiPo battery 3.7V 1400mAh. Note: These batteries can only be shipped by ground, limiting delivery to EU destinations.
UEXT modules: Various accessories such as sensors (temperature, humidity, pressure, magnetic field, light), LCDs, LED matrix, Relays, Bluetooth, Zigbee, Wi-Fi, GSM, GPS, RFID, RTC, EKG, etc., that connect to the UEXT connector.

ESP32-POE-ISO and Accessories

ESP32-POE-ISO: Commercial grade 0-70°C board with internal antenna.
ESP32-POE-ISO-EA: Commercial grade 0-70°C board with external antenna.
ESP32-POE-ISO-IND: Industrial grade -40 to +85°C board with internal antenna.
ESP32-POE-ISO-EA-IND: Industrial grade -40 to +85°C board with external antenna.
ESP32-POE-ISO-WROVER: Commercial grade 0-70°C board with 8MB PSRAM and internal antenna.
ESP32-POE-ISO-WROVER-EA: Commercial grade 0-70°C board with 8MB PSRAM and external antenna.
BATTERY-LIPO1400mAh: LiPo battery 3.7V 1400mAh. Note: These batteries can only be shipped by ground, limiting delivery to EU destinations.
UEXT modules: Various accessories such as sensors (temperature, humidity, pressure, magnetic field, light), LCDs, LED matrix, Relays, Bluetooth, Zigbee, Wi-Fi, GSM, GPS, RFID, RTC, EKG, etc., that connect to the UEXT connector.

Hardware Layout and GPIOs

ESP32-POE Layout

The ESP32-POE board features the ESP32 module, a USB connector for programming, an Ethernet connector for network and PoE input, a UEXT connector for expansion, and a LiPo battery connector. It also includes a user button, a reset button, and mounting holes.

ESP32-POE GPIOs

The board exposes various GPIO pins and power/control signals. These include:

Power/Control: +5V, +3.3V, GND, ESP_EN (resets ESP32 module)
General Purpose GPIOs: GPIO0, GPIO1, GPIO2, GPIO3, GPIO4, GPIO5, GPIO13, GPIO14, GPIO15, GPIO16, GPIO32, GPIO33, GPIO34, GPIO35, GPIO36, GPIO39, GPIO139.

Specific GPIO usage:

GPIO0, GPIO1: Used during programming, otherwise free.
GPIO2, GPIO14, GPIO15: Used for the SD-card; available if no SD card is used.
GPIO2, GPIO4, GPIO5, GPIO13, GPIO14, GPIO15, GPIO16, GPIO36: Shared between UEXT and EXT1/EXT2 connectors. Use caution to avoid conflicts.
GPIO39: Connected to measure external power supply voltage.
GPIO34: Connected to the user button and has a 10K pull-up resistor.
GPIO35: Available for use, can be connected to measure LiPo battery voltage via the SENS_BAT_E1 solder jumper.

Note: The ESP32-POE-WROVER variant has GPIO16 disconnected.

ESP32-POE-ISO Layout

The ESP32-POE-ISO board shares a similar layout to the ESP32-POE, featuring the ESP32 module, USB connector, Ethernet connector, UEXT connector, LiPo battery connector, user button, reset button, and mounting holes. The primary difference is the inclusion of galvanic isolation.

ESP32-POE-ISO GPIOs

The GPIO pinout for the ESP32-POE-ISO is similar to the ESP32-POE. It includes:

Power/Control: +5V, +3.3V, GND, ESP_EN (resets ESP32 module)
General Purpose GPIOs: GPIO0, GPIO1, GPIO2, GPIO3, GPIO4, GPIO5, GPIO13, GPIO14, GPIO15, GPIO16, GPIO32, GPIO33, GPIO34, GPIO35, GPIO36, GPIO39.

Specific GPIO usage is the same as for the ESP32-POE, with the same notes regarding shared pins and the ESP32-POE-WROVER variant.

Schematics

The latest schematics and board revision changes for both ESP32-POE and ESP32-POE-ISO are available on GitHub:

ESP32-POE latest schematic Rev.L: GitHub
ESP32-POE board revision changes: GitHub
ESP32-POE-ISO schematic Rev.L: GitHub
ESP32-POE-ISO board revision changes: GitHub

Power Supply

The ESP32-POE(-ISO) can be powered from four sources:

Ethernet PoE
USB-micro connector
LiPo battery
EXT1 pin 1 (+5V). Note: This pin is connected to the USB 5V signal; do not connect the board to USB when powering via this pin.

Power consumption ranges from 50 to 200mA depending on the operation mode. When a LiPo battery is connected, it is automatically charged at approximately 100mA when an external power supply is attached. If the LiPo battery is connected and the external power supply is missing, an internal DCDC step-up converter and switching circuit automatically powers the ESP32-POE from the battery. A 1400mAh battery provides approximately 8 hours of standalone operation.

The LiPo battery connector is a JST 2.0 mm connector, designed for Olimex's battery polarity. If using batteries from other manufacturers, ensure the [PLUS and MINUS] terminals are connected correctly to avoid damaging the board.

UEXT Connector

The UEXT connector is a Universal EXTension connector providing +3.3V, GND, I2C, SPI, and UART signals. It is a 0.1" (2.54mm) pitch boxed plastic connector, with all signals operating at 3.3V levels.

Olimex offers a variety of modules for the UEXT connector, including sensors for temperature, humidity, pressure, magnetic field, and light, as well as modules for LCDs, LED matrix, Relays, Bluetooth, Zigbee, Wi-Fi, GSM, GPS, RFID, RTC, and EKG.

The UEXT connector pinout is as follows:

Power/Ground: +3.3V, GND
UART: U1TXD, U1RXD
I2C: I2C-SCL, I2C-SDA
SPI: HS2_CMD, HS2_DATA0, HS2_CLK, VSPICS0
GPIOs: GPIO4, GPIO16, GPIO15, GPIO14, GPIO13, GPIO2, GPIO5, GPIO36, GPIO33, GPIO32, GPIO34, GPIO35, GPIO39.

Software Support

The ESP32-POE and ESP32-POE-ISO boards are popular and well-supported by the following development environments:

Espressif ESP-IDF
MicroPython
Arduino IDE
Esphome
PlatformIO

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