esp-dev-kits Choose target... Choose version... ESP32-S31 Boards ESP32-S31-Function-CoreBoard-1 User Guide ESP32-S31-Korvo-1 Resources and Legal Notices Related Documentation and Resources Disclaimer and Copyright Notice esp-dev-kits ESP32-S31-Function-CoreBoard-1 Download PDF ESP32-S31-Function-CoreBoard-1 [中文] The ESP32-S31-Function-CoreBoard-1 is a development board based on the ESP32-S31-WROOM-3 module with Wi-Fi, Bluetooth Classic, Bluetooth LE, and IEEE 802.15.4. It integrates Gigabit Ethernet, USB 2.0 OTG, and onboard audio peripherals for connected IoT applications. User Guide Getting Started Hardware Reference Hardware Revision Details Related Documents Next Previous Suggestion on this document? Provide feedback Help improve this document? Edit on GitHub Need more information? Check ESP forum Sales Questions Technical Inquiries © Copyright 2016 - 2026, Espressif Systems (Shanghai) CO., LTD Built with Sphinx using a theme based on Read the Docs Sphinx Theme. esp-dev-kits Choose target... Choose version... ESP32-S31 Boards ESP32-S31-Function-CoreBoard-1 User Guide Getting Started Description of Components Start Application Development Contents and Packaging Hardware Reference Block Diagram Current Measurement Header Block Hardware Revision Details Related Documents ESP32-S31-Korvo-1 Resources and Legal Notices Related Documentation and Resources Disclaimer and Copyright Notice esp-dev-kits ESP32-S31-Function-CoreBoard-1 ESP32-S31-Function-CoreBoard-1 Download PDF ESP32-S31-Function-CoreBoard-1 [中文] This user guide will help you get started with ESP32-S31-Function-CoreBoard-1 and provides detailed information about this development board. The ESP32-S31-Function-CoreBoard-1 is a development board based on the ESP32-S31-WROOM-3 module with Wi-Fi, Bluetooth Classic, Bluetooth LE, and IEEE 802.15.4. It integrates Gigabit Ethernet, USB 2.0 OTG, and onboard audio peripherals for connected IoT applications. Most of the I/O pins on the module are broken out to pin header J2 for easy interfacing. ESP32-S31-Function-CoreBoard-1 (with ESP32-S31-WROOM-3 module on board) The document consists of the following major sections: Getting Started: Overview of ESP32-S31-Function-CoreBoard-1 and hardware/software setup instructions to get started. Hardware Reference: More detailed information about the ESP32-S31-Function-CoreBoard-1’s hardware. Hardware Revision Details: Information about revision history, known issues, and links to user guides for previous versions (if any). Related Documents: Links to related documentation. Getting Started This section briefly introduces ESP32-S31-Function-CoreBoard-1 and explains how to perform the initial hardware setup and how to flash firmware onto the board. Description of Components ESP32-S31-Function-CoreBoard-1 - front (click to enlarge) ESP32-S31-Function-CoreBoard-1 - back (click to enlarge) The following table lists the key components on the front and back of the board in clockwise order. No. Key Component Description 1 J2 All available GPIO pins are broken out to header J2 for easy interfacing. For more details, see Header Block. 2 RJ45 Ethernet Port An Ethernet port supporting 10/100/1000 Mbps auto-negotiation. 3 Ethernet Transformer Transformer module for the RJ45 Ethernet port. 4 USB 2.0 Type-A Port The USB 2.0 Type-A port is connected to the USB 2.0 OTG High-Speed interface of the ESP32-S31, compliant with the USB 2.0 specification. When communicating with other devices via this port, the ESP32-S31 acts as a USB host, providing up to 500 mA of current. 5 USB Serial/JTAG Port USB Type-C port that supports USB 2.0 Full-Speed data rate. It can be used to supply power to the board, flash firmware to the ESP32-S31 chip, communicate with the chip via the USB protocol, and perform JTAG debugging. 6 USB Type-C to UART Port Used for power supply to the board, flashing applications to the chip, as well as communication with the ESP32-S31 chip via the on-board USB-to-UART bridge. 7 3.3 V Power-on LED Turns on when the board is connected to USB power. 8 J5 Used for current measurement. See details in section Current Measurement. 9 5 V to 3.3 V DC/DC Converter Power regulator that converts a 5 V supply into a 3.3 V output. 10 ESP32-S31-WROOM-3 ESP32-S31-WROOM-3 integrates the ESP32-S31 chip and supports Bluetooth 5.4 (LE) and IEEE 802.15.4 (Zigbee/Thread/Matter), suitable for a wide range of low-power IoT applications. No. Key Component Description 11 Microphone Onboard microphone connected to the interface of the audio codec chip. 12 RGB LED Addressable RGB LED, driven by GPIO60. 13 Audio Codec Chip ES8311 is a low-power mono audio codec. It includes a single-channel ADC, a single-channel DAC, a low-noise pre-amplifier, a headphone driver, digital sound effects, analog mixing, and gain functions. It interfaces with the ESP32-S31 chip over I2S and I2C buses to provide hardware audio processing independent of the audio application. 14 Reset Button Press this button to reset the ESP32-S31. 15 Speaker Output Port This port is used to connect a speaker. The maximum output power can drive a 4 Ω, 3 W speaker. The pin spacing is 1.25 mm (0.08”). 16 Boot Button Download button. Holding down Boot and then pressing Reset initiates Firmware Download mode for downloading firmware through the UART port or USB Serial/JTAG port. 17 Audio PA Chip NS4150B is an EMI-compliant, 3 W mono Class D audio power amplifier that amplifies audio signals from the audio codec chip to drive speakers. 18 Ethernet PHY IC Ethernet PHY chip connected to the ESP32-S31 RGMII interface and the RJ45 Ethernet port. 19 USB-to-UART Bridge Single-chip USB-to-UART bridge that works with the USB Type-C to UART Port for board power, firmware flashing, and serial communication with the ESP32-S31 chip. 20 Switch TPS2051C is a USB power switch that provides a 500 mA output current limit. Start Application Development Before powering up your ESP32-S31-Function-CoreBoard-1, please make sure that it is in good condition with no obvious sign of damage. Required Hardware ESP32-S31-Function-CoreBoard-1 USB 2.0 cable (USB-A to Type-C) Computer running Windows, Linux, or macOS Note Be sure to use a good quality USB cable. Some cables are for charging only and do not provide the needed data lines and will not work for programming this board. Hardware Setup Connect the ESP32-S31-Function-CoreBoard-1 to your computer using a USB cable. The board can be powered through any of the USB Type-C ports. Software Setup Please proceed to ESP-IDF Get Started, which will help you set up the development environment quickly and then flash an application onto your board. Note The board uses a USB port to communicate with the computer. Most operating systems (Windows, Linux, macOS) come with the required drivers pre-installed and the board is recognized automatically once plugged in. If the device cannot be recognized or a serial connection cannot be established, refer to Establish Serial Connection with ESP32-S31 for detailed driver installation steps. Espressif provides board peripheral management components for many development boards to help you initialize and use key onboard peripherals such as LCD, audio codec, keys, and LEDs more easily and efficiently. Please visit the esp_board_manager component in ESP Component Registry for support coverage. Other Development Framework Options In addition to ESP-IDF, this board supports the following frameworks and options for different user needs: Espressif Bluetooth LE ecosystem: Develop Bluetooth LE applications using solutions such as ESP-BLE-MESH and ESP-BLE-AUDIO to accelerate time-to-market and mass production. ESP-GMF: Espressif general multimedia framework with audio/video processing components for multimedia applications. Wi-Fi audio/video examples: Sample Wi-Fi audio and video applications to help integrate multimedia features into your project. Bluetooth audio: Unified Bluetooth audio APIs supporting Bluetooth Classic and LE Audio. ESP-Matter: Build Matter and Thread devices suited to low-power and battery-powered scenarios. Contents and Packaging Retail Orders If you order a few samples, each ESP32-S31-Function-CoreBoard-1 comes in an individual package in either an antistatic bag or any other packaging depending on your retailer. For retail orders, please go to Get Samples. Wholesale Orders If you order in bulk, the boards come in large cardboard boxes. For wholesale orders, please go to Contact Us. Hardware Reference Block Diagram The main components of ESP32-S31-Function-CoreBoard-1 and their interconnections are shown in the block diagram below. ESP32-S31-Function-CoreBoard-1 block diagram (click to enlarge) Power Supply Options The board can be powered using one of the following options: Via the USB-to-UART port or the ESP32-S31 USB port (either port or both), default method (recommended) 5V and G (GND) pin headers Current Measurement The J5 headers on ESP32-S31-Function-CoreBoard-1 (see J5 in Figure ESP32-S31-Function-CoreBoard-1 - front (click to enlarge)) can be used for measuring the current drawn by the ESP32-S31-WROOM-3 module: Remove the jumper: Power supply between the module and peripherals on the board is cut off. To measure the module’s current, connect an ammeter in series via the J5 headers. Apply the jumper (factory default): Restore the board’s normal functionality. Header Block The table below provides the Name and Function of pin header J2. The pin names are shown in Figure ESP32-S31-Function-CoreBoard-1 - front (click to enlarge). The numbering is the same as in the ESP32-S31-Function-CoreBoard-1 schematic (PDF). J2 No. Name Type [1] Function 1 G G Ground 2 G G Ground 3 TX0 I/O/T U0TXD, GPIO58 4 RXD I/O/T U0RXD, GPIO59 5 61 I/O/T BOOT, GPIO61 6 60 I/O/T GPIO60 [2] 7 2 I/O/T GPIO23 8 G G Ground 9 0 I/O/T GPIO0 10 3 I/O/T GPIO3 11 49 I/O/T GPIO49 12 1 I/O/T GPIO1 13 47 I/O/T GPIO47 14 48 I/O/T GPIO48 15 45 I/O/T GPIO45 16 46 I/O/T GPIO46 17 43 I/O/T GPIO43 18 44 I/O/T GPIO44 19 4