Olimex ESP32-POE and ESP32-POE-ISO User Manual

Introduction to ESP32-POE

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

Important notice: The ESP32-PoE lacks galvanic isolation from the Ethernet power supply. When programming the board via the micro USB connector, disconnect the Ethernet cable if it is powered via PoE. To protect your computer and board from accidental short circuits, consider using the Olimex USB-ISO or the Olimex ESP32-POE-ISO board, which offers insulation.

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 features the ESP32-WROVER-E module with 4MB flash and 8MB PSRAM. The ESP32-POE-WROVER-EA uses the ESP32-WROVER-IE module, which includes a U.FL connector and an external antenna.

ESP32-POE Features

• ESP32-WROOM-32E module with 4MB Flash and 520 KB SRAM.
• High-reliability industrial grade (-40+85°C) available (-IND).
• CE-RED and LVD certification.
• Original design by OLIMEX Ltd.
• Power Over Ethernet negotiation circuit compliant with 802.3, 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 with 0.1" step spaced at 1".
• PCB dimensions: (80 x 28)mm ~ (3.15 x 1.1)".

ESP32-POE-ISO Features

• ESP32-WROOM-32E module with 4MB Flash and 520 KB SRAM.
• Power Over Ethernet negotiation circuit compliant with 802.3, with a minimum operating voltage of 35VDC.
• High-reliability industrial grade (-40+85°C) available (-IND).
• CE-RED and LVD certification.
• Original design by OLIMEX Ltd.
• Low power design with 200uA 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 converter.
• UEXT connector.
• User button.
• Reset button.
• Two extension connectors, 0.1" step spaced at 1".
• PCB dimensions: (98 x 28)mm ~ (3.8 x 1)".

PoE Standard

The ESP32-POE and ESP32-POE-ISO follow the original 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 assured to be available at the powered device, as some power dissipates in the cable.

The ESP32-POE-ISO features a 2W DC-DC 5V-5V insulation converter, limiting its power usage to 2W.

Differences between ESP32-POE and ESP32-POE-ISO

The ESP32-POE is not galvanically isolated, making it unsafe to connect to devices using non-isolated power supplies. ? This means you should NOT connect the ESP32-POE to a computer's USB port while it is powered by Ethernet PoE. Doing so could damage the board, your computer, or both, and will void the warranty.

The ESP32-POE-ISO provides 3000VDC galvanic insulation between the Ethernet PoE part and the ESP32 power supply, allowing safe USB and programming/debugging connections while powered by Ethernet PoE.

Differences between ESP32-POE and ESP32-POE-WROVER

The ESP32-POE uses the ESP32-WROOM-32E module with 4MB Flash and 520KB RAM. The ESP32-POE-WROVER uses the ESP32-WROVER-E module with 4MB Flash and 8MB PSRAM.

? The WROVER module utilizes two GPIOs to connect to the PSRAM, rendering these GPIOs unusable for other purposes.

Order Codes

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+85°C board with internal antenna.
• ESP32-POE-EA-IND: Industrial grade -40+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 modules including sensors (temperature, humidity, pressure, magnetic field, light), LCDs, LED matrix, Relays, Bluetooth, Zigbee, WiFi, GSM, GPS, RFID, RTC, EKG, and more, which can be connected 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+85°C board with internal antenna.
• ESP32-POE-ISO-EA-IND: Industrial grade -40+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 modules including sensors (temperature, humidity, pressure, magnetic field, light), LCDs, LED matrix, Relays, Bluetooth, Zigbee, WiFi, GSM, GPS, RFID, RTC, EKG, and more, which can be connected to the UEXT connector.

HARDWARE

ESP32-POE Layout

The ESP32-POE board features:

• Top Side: ESP32 module, Reset button, User button, UEXT connector, Micro USB connector, Ethernet connector, mounting holes, and various components.
• Bottom Side: MicroSD card connector, various ICs, resistors, capacitors, and mounting holes.

Key Components Labeled:

• ESP32 module
• Reset button
• User button
• Micro USB connector
• UEXT connector
• Ethernet connector
• Micro SD card connector
• LiPo battery connector
• Mounting holes

ESP32-POE GPIOs

The ESP32-POE board exposes several GPIO pins. The following table details the pin assignments:

• Power Pins: +5V, +3.3V, GND
• Control Pins: ESP_EN
• General Purpose IOs: GPIO0, GPIO1, GPIO2, GPIO3, GPIO4, GPIO5, GPIO13, GPIO14, GPIO15, GPIO16, GPIO32, GPIO33, GPIO34, GPIO35, GPIO36, GPIO39.

Pin Descriptions:

• +5V: Can be used as input or output. When connected to USB or Ethernet PoE, it acts as an output. If used as input for external 5V power, ensure the board is not connected to USB. Maximum output current is 0.8A @ 5V (4W), including the 3.3V output.
• +3.3V: Output can source up to 0.5A @ 3.3V (1.65W). The combined power from +3.3V and +5V must not exceed 4W.
• ESP_EN: Resets the ESP32 module.
• GPIO0, GPIO1: Used for programming; available after programming.
• GPIO2, GPIO14, GPIO15: Used for the SD-card; available if no SD card is inserted.
• GPIO2, GPIO4, GPIO5, GPIO13, GPIO14, GPIO15, GPIO16, GPIO36: Shared between UEXT and EXT1,2 connectors. Use on one connector means it cannot be used on the other.
• GPIO39: Used to measure external power supply voltage.
• GPIO34: Connected to the user button and has a 10K pull-up resistor.
• GPIO35: Free for use, can be connected to measure LiPo battery voltage via the SENS_BAT_E1 solder jumper.

? The ESP32-POE-WROVER does not have GPIO16 connected.

ESP32-POE-ISO Layout

The ESP32-POE-ISO board features:

• Top Side: ESP32 module, Reset button, User button, UEXT connector, USB-UART connector, mounting holes, and various components.
• Bottom Side: Ethernet connector, various ICs, capacitors, and mounting holes.

Key Components Labeled:

• ESP32 module
• Reset button
• User button
• UEXT connector
• USB-UART connector
• Ethernet connector
• Mounting holes

ESP32-POE-ISO GPIOs

The ESP32-POE-ISO board exposes several GPIO pins. The following table details the pin assignments:

• Power Pins: +5V, +3.3V, GND
• Control Pins: ESP_EN
• General Purpose IOs: GPIO0, GPIO1, GPIO2, GPIO3, GPIO4, GPIO5, GPIO13, GPIO14, GPIO15, GPIO16, GPIO32, GPIO33, GPIO34, GPIO35, GPIO36, GPIO39.

Pin Descriptions:

• +5V: Can be used as input or output. When connected to USB or Ethernet PoE, it acts as an output. If used as input for external 5V power, ensure the board is not connected to USB. Maximum output current is 0.2A @ 5V (1W), including the 3.3V output. The combined power must not exceed 1W.
• +3.3V: Output can source up to 0.33A @ 3.3V (1W). The combined power from +3.3V and +5V must not exceed 1W.
• ESP_EN: Resets the ESP32 module.
• GPIO0, GPIO1: Used for programming; available after programming.
• GPIO2, GPIO14, GPIO15: Used for the SD-card; available if no SD card is inserted.
• GPIO2, GPIO4, GPIO5, GPIO13, GPIO14, GPIO15, GPIO16, GPIO36: Shared between UEXT and EXT1,2 connectors. Use on one connector means it cannot be used on the other.
• GPIO39: Used to measure external power supply voltage.
• GPIO34: Connected to the user button and has a 10K pull-up resistor.
• GPIO35: Free for use, can be connected to measure LiPo battery voltage via the SENS_BAT_E1 solder jumper.

? The ESP32-POE-WROVER has no GPIO16 connected.

Schematics

The latest schematics for ESP32-POE (Rev.L) and ESP32-POE-ISO (Rev.L) are available on GitHub. Board revision changes are also documented on GitHub.

Power Supply

ESP32-POE(-ISO) Power Supply

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

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

The power consumption of the ESP32-POE(-ISO) ranges from 50 to 200mA, depending on the operation mode. If a LiPo battery is connected, it is charged automatically when a power supply is attached, drawing approximately 100mA. When the LiPo battery is attached and the external power supply is missing, the internal DCDC step-up converter and switching circuit automatically power 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, compatible with 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 that includes +3.3V, GND, I2C, SPI, and UART signals. It is a 0.1" (2.54mm) spaced boxed plastic connector, and all signals operate at 3.3V levels. The UEXT connector shares some pins with EXT1 and EXT2.

UEXT Connector Pinout:

• +3.3V
• GND
• GPIO4 / U1TXD
• U1RXD / GPIO36
• GPIO16 / I2C-SCL
• I2C-SDA / GPIO13
• GPIO15 / HS2_CMD
• HS2_DATA0 / GPIO2
• GPIO14 / HS2_CLK
• VSPICSO / GPIO5

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

SOFTWARE

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

• Espressif ESP-IDF
• MicroPython
• Arduino IDE
• Esphome
• PlatformIO

Revision History

Revision 1.0 May 2023