esp-dev-kits Choose target... Choose version... ESP32-S31 Boards ESP32-S31-Function-CoreBoard-1 ESP32-S31-Korvo-1 User Guide Resources and Legal Notices Related Documentation and Resources Disclaimer and Copyright Notice esp-dev-kits ESP32-S31-Korvo-1 Download PDF ESP32-S31-Korvo-1 [中文] The ESP32-S31-Korvo-1 is a multimedia development board based on the ESP32-S31 chip with the ESP32-S31-WROOM-3 module. It includes a dual-microphone array for speech recognition and near/far-field wake-up; integrates peripherals such as LCD, camera, and microSD; supports JPEG-based video streaming; and targets low-cost, low-power, connected audio/video and graphical UI product development. This document describes revision V1.1. 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 ESP32-S31-Korvo-1 User Guide Getting Started Description of Components Development Board Accessories Start Application Development Contents and Packaging Hardware Reference Block Diagram Power Supply Description microSD Card and SPI NAND Flash Pin Assignment Table Hardware Setup Options Hardware Revision Details Related Documents Resources and Legal Notices Related Documentation and Resources Disclaimer and Copyright Notice esp-dev-kits ESP32-S31-Korvo-1 ESP32-S31-Korvo-1 V1.1 Download PDF ESP32-S31-Korvo-1 V1.1 [中文] This user guide will help you get started with ESP32-S31-Korvo-1 V1.1 and provide detailed information about this development board. The ESP32-S31-Korvo-1 V1.1 is a multimedia development board based on the ESP32-S31 chip. It features a dual-microphone array and supports speech recognition as well as near- and far-field wake-up. The board also integrates peripherals such as LCD, camera, and microSD, and supports JPEG-based video streaming for low-cost, low-power, connected audio/video and graphical UI product development. ESP32-S31-Korvo-1 V1.1 (with ESP32-S31-WROOM-3 module on board) The ESP32-S31-Korvo-1 V1.1 main board can be used together with an LCD expansion board. This document focuses on this board; more information about the LCD expansion board will be added when the related documentation is available. The document consists of the following major sections: Getting Started: Overview of ESP32-S31-Korvo-1 V1.1 and hardware/software setup instructions to get started. Hardware Reference: More detailed information about the ESP32-S31-Korvo-1 V1.1 hardware. Hardware Revision Details: Information about revision history, known issues, and links to user guides for previous versions. Related Documents: Links to related documentation. Getting Started This section briefly introduces ESP32-S31-Korvo-1 V1.1 and explains how to perform the initial hardware setup and how to flash firmware onto the board. Description of Components ESP32-S31-Korvo-1 V1.1 (click to enlarge) The following list describes the key components on the board in a clockwise direction. No. Component Description 1 USB Type-C Port (Power) Power input only; no data communication. 2 USB Type-C Port (UART) Can power the board, flash firmware to the chip, and communicate with the ESP32-S31 via the onboard USB-to-UART bridge. 3 USB-to-UART Bridge Single-chip USB-to-UART bridge supporting up to 3 Mbps. 4 Power Switch Slide toward ON to apply 5 V power; slide away from ON to disconnect 5 V power. 5 USB 2.0 Type-A Port Connected to the ESP32-S31 USB 2.0 OTG High-Speed interface and supports the USB 2.0 standard. When used for USB communication, ESP32-S31 acts as a USB Host connected to downstream USB devices, providing up to 500 mA output current. 6 Buck Converter Buck DC-DC converter for 3.3 V system power. 7 5 V Power-on LED Lights when USB power is connected to the board. 8 Switch TPS2051C USB power switch with 500 mA current limit. 9 Right Speaker Output Port Right-channel speaker output; can drive a 4 Ω, 3 W speaker. The pin spacing is 2.00 mm (0.08”). 10 Right Microphone Onboard right analog microphone routed to the audio codec. 11 5 V to 3.3 V LDO Converts 5 V to 3.3 V for the audio circuitry. 12 Right Audio PA Chip NS4150B low-EMI 3 W mono class-D amplifier driving the right speaker from the codec output. 13 Function Buttons Four buttons: PLAY, SET, VOL-, and VOL+, connected to ESP32-S31-WROOM-3 for UI control and audio application testing via dedicated APIs. 14 Audio Codec Chip ES8389 low-power stereo codec with dual ADC/DAC, low-noise preamp, headphone driver, digital effects, analog mixing, and gain control. Connected to the ESP32-S31 over I2S and I2C for hardware audio processing independent of application software. 15 Left Audio PA Chip NS4150B low-EMI 3 W mono class-D amplifier driving the left speaker from the codec output. 16 Left Microphone Onboard left analog microphone routed to the audio codec. 17 Left Speaker Output Port Left-channel speaker output; can drive a 4 Ω, 3 W speaker. The pin spacing is 2.00 mm (0.08”). 18 RGB LED Addressable RGB LED driven by GPIO8. No. Component Description 19 3.3 V to 1.8 V LDO (NC) Converts 3.3 V to 1.8 V for 1.8 V SPI NAND flash. Not populated by default (NC). 20 SPI NAND Flash (NC) Quad SPI NAND flash sharing ESP32-S31-WROOM-3 signals with the microSD interface. Not populated by default (NC). 21 LCD Connector Connector for an external LCD daughterboard. 22 ESP32-S31-WROOM-3 ESP32-S31-WROOM-3 is a general-purpose module supporting 2.4 GHz Wi-Fi 6, Bluetooth 5.4, Bluetooth Classic, and IEEE 802.15.4 (Zigbee 3.0 and Thread 1.4). The module integrates ESP32-S31, 16 MB SPI flash, and 16 MB PSRAM, and uses an onboard PCB antenna. 23 microSD Card Slot Supports 4-bit microSD for audio storage and playback. SDIO 3.0 capable. 24 3.3 V to 2.8 V LDO Converts 3.3 V to 2.8 V for the external camera module. 25 3.3 V to 1.5 V LDO Converts 3.3 V to 1.5 V for the external camera module. 26 Camera Connector Connector for an external camera module for image transfer. 27 Reset Button System reset. 28 Boot Button Firmware download: hold Boot, press and release Reset to enter download mode; flash over the serial port. Development Board Accessories The ESP32-S31-Korvo-1 V1.1 package may include the following optional accessories. The main board and accessories can also be purchased separately. Available accessories include: LCD expansion board: ESP32-S3-LCD-EV-Board-SUB3 OV3660 camera module Start Application Development Before powering up the board, please make sure that it is in good condition with no obvious sign of damage. Required Hardware ESP32-S31-Korvo-1 V1.1 One or two speakers Two USB 2.0 cables (Standard-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 nor work for programming the board. Optional Hardware microSD card Hardware Setup Connect one or two speakers to the speaker output port(s). Plug in two USB cables from the PC to both USB ports on the board. Turn on the power switch. The red power LED should light. 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 USB ports 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 on the 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-Brookesia: Human-machine interaction framework for AIoT devices for graphical UI and smart display applications. ESP-GMF: Espressif general multimedia framework with audio/video processing components for multimedia applications. Bluetooth audio: Unified Bluetooth audio APIs supporting Bluetooth Classic and LE Audio. ESP Video Components: Camera, video streaming, and video processing components for image capture and video applications. 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 board 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-Korvo-1 V1.1 and their interconnections are shown in the block diagram below. ESP32-S31-Korvo-1 V1.1 electrical block diagram (click to enlarge) Power Supply Description USB Power Both USB Type-C ports can power the board: the Power port is power-only, while the UART port can supply power and carry data. When driving high-power speakers and using the USB Type-A port to power external devices at the same time, ensure the total input current to the board meets 3 A. Use a dedicat