esp-dev-kits Choose target... Choose version... ESP32-S31 Boards ESP32-S31-Function-CoreBoard-1 User Guide ESP32-S31-Korvo-1 ESP-Mosaico 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 for connected AIoT prototyping based on the ESP32-S31-WROOM-3 module. It supports Wi-Fi 6, IEEE 802.15.4, Bluetooth 5.4 (LE + BR/EDR), and Gigabit Ethernet; provides an onboard microphone and speaker output; routes out all key GPIOs; and supports out-of-the-box AI voice interaction evaluation. User Guide Getting Started Hardware Reference Hardware Revision Details Related Documents Disclaimer and Copyright Notice 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 ESP32-S31-Korvo-1 ESP-Mosaico Resources and Legal Notices Related Documentation and Resources Disclaimer and Copyright Notice Terms of Use for Development Board esp-dev-kits Disclaimer and Copyright Notice Download PDF Disclaimer and Copyright Notice [中文] Information in this document, including URL references, is subject to change without notice. All third party’s information in this document is provided as is with no warranties to its authenticity and accuracy. No warranty is provided to this document for its merchantability, non-infringement, fitness for any particular purpose, nor does any warranty otherwise arising out of any proposal, specification or sample. All liability, including liability for infringement of any proprietary rights, relating to use of information in this document is disclaimed. No licenses express or implied, by estoppel or otherwise, to any intellectual property rights are granted herein. The Wi-Fi Alliance Member logo is a trademark of the Wi-Fi Alliance. The Bluetooth logo is a registered trademark of Bluetooth SIG. All trade names, trademarks and registered trademarks mentioned in this document are property of their respective owners, and are hereby acknowledged. Terms of Use for Development Board The development board is intended for R&D evaluation, engineering design verification, and early-stage product development. It is provided as a convenient platform for development and testing. The development board is not intended as a mass-production component or as a finished product for end consumers; therefore, its product management approach differs from that of mass-produced chips and modules. The development board has not obtained specific national or industry certifications and is not covered under regulatory frameworks such as CE, UL, or CCC. As a result, it may not meet the requirements of such regulations. Users should ensure that their use of the development board complies with the applicable laws and regulations of the country or region in which it is used. In addition, the development board has not been designed, validated, or managed for reliability testing, production, or commercial deployment purposes. Users assume full responsibility for the correct and safe use of the product. For applications beyond the intended use of the development board, including but not limited to pre-production testing, system integration, final product delivery, or other commercial uses, the user should, before mass production and in light of its own product requirements, fully evaluate the technical suitability, reliability requirements, regulatory compliance, and system integration risks associated with such applications. The user should also complete all necessary verification, testing, and certification activities relating to system-level design, product certification, reliability validation, regulatory compliance assessment, and commercial deployment. Espressif assumes no liability arising from applications beyond the intended use of the development board. Regardless of whether the parties have entered into a supplier framework agreement, quality agreement, or any other similar agreement, the development board is not subject to any requirements or commitments therein relating to product certification, reliability management, return material analysis (RMA), product/process change notification (PCN), end-of-life (EOL) management, long-term supply commitments, or any other requirements and commitments established under a mass-production product management model. 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 Disclaimer and Copyright Notice ESP32-S31-Korvo-1 ESP-Mosaico 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 for connected AIoT prototyping based on the ESP32-S31-WROOM-3 module. It supports Wi-Fi 6, IEEE 802.15.4, Bluetooth 5.4 (LE + BR/EDR), and Gigabit Ethernet; provides an onboard microphone and speaker output; routes out all key GPIOs; and supports out-of-the-box AI voice interaction evaluation. 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. Disclaimer and Copyright Notice: Link to the disclaimer and copyright notice. 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 boa