Introduction of Espressif ESP32-S31 Chip

Espressif's ESP32-S31 is a high-performance, multi-protocol wireless SoC chip designed for the next generation of AIoT, edge computing, and rich Human-Machine Interfaces (HMI). As a major upgrade to the ESP32-S3, the ESP32-S31 achieves comprehensive enhancements in computing architecture, memory throughput, wireless connectivity standards, and hardware acceleration for graphics and audio.

I. Key Features of the ESP32-S31 Chip

1. Significant Leap in Architecture and Compute Power

  • High-Frequency Dual-Core Architecture: Powered by a 32-bit dual-core RISC-V architecture with clock speeds up to 320 MHz (compared to the ESP32-S3's 240 MHz Xtensa architecture), delivering approximately a 65% increase in CoreMark performance over its predecessor.
  • Vector/SIMD and AI Acceleration: Integrates a single-precision FPU and a 128-bit data bus with support for SIMD instruction acceleration, dramatically speeding up local neural network inference (such as micro-YOLO series models and Keyword Spotting/KWS).
  • Low-Power Co-processor (LP System): Features an independent, single-core ULP RISC-V low-power system (up to 40 MHz) with 32 KB of LP SRAM to efficiently monitor sensor signals while the main cores sleep.

2. Fully Integrated Multi-Protocol Wireless Connectivity

  • Wi-Fi 6 (802.11ax): Supports the 2.4 GHz band with OFDMA, MU-MIMO, and TWT (Target Wake Time) features, improving throughput in high-density networks while reducing device power consumption.
  • Dual-Mode Bluetooth and LE Audio: Supports Bluetooth 5.4 (LE) and Bluetooth Mesh 1.1, while natively re-introducing Bluetooth Classic (BR/EDR). It also supports LE Audio (LC3 codec, BIS/CIS multi-stream audio) as well as Bluetooth AoA/AoD direction-finding.
  • IEEE 802.15.4: Supports Thread 1.4 and Zigbee 3.0, fully compatible with the Matter ecosystem.

3. Expanded Memory and Bus Bandwidth

  • Parallel Access and High-Frequency PSRAM: The external PSRAM interface is upgraded to 250 MHz 8-bit DDR PSRAM, significantly increasing throughput bandwidth and supporting hardware-level parallel access to Flash and PSRAM.
  • Rich Bus Expansion: Exposes up to 60 GPIOs and features an integrated Gigabit Ethernet MAC (1000 Mbps), CAN FD controller (ISO 11898-1:2015 compliant), and USB 2.0 High-Speed OTG.

4. Advanced HMI and Multimedia Hardware Acceleration

  • Graphics Hardware Acceleration Engine: Integrates a PPA (Pixel Processing Accelerator) and 2D-DMA, enabling hardware-based image rotation, scaling, Alpha blending, and RGB888 / RGB565 color depth conversion to smoothly drive displays up to 720P resolution.
  • Hardware JPEG Codec: Built-in dedicated JPEG hardware codec handles image and video compression/decompression directly, removing heavy CPU overhead.
  • Dual I2S and Hardware-Level Audio Sync: Dual I2S controllers paired with the Bluetooth baseband achieve hardware-level audio synchronization without complex software clock compensation, noticeably minimizing audio latency.

II. Typical Application Scenarios for ESP32-S31

Leveraging its high compute power, rich peripherals, hardware graphics/video acceleration, and full-protocol connectivity, the ESP32-S31 is tailored for terminal designs in the following domains:

  • Edge AI Smart Hardware & Voice Interaction Terminals
    • AI Toys & Conversational Robots: With 320 MHz dual-core RISC-V acceleration and higher PSRAM bandwidth, it smoothly runs on-device VAD, voice wake-word detection (KWS), and local vision recognition algorithms, as well as efficiently interfacing with Large Language Models (LLM / AI Agent clients).
    • Smart Speakers & Bluetooth Audio Nodes: Utilizing dual-mode Bluetooth Classic + LE Audio features, it can accept audio streams from traditional smartphones while also functioning as a transmitter or receiver node for distributed multi-room audio broadcasts.
  • Multimedia Human-Machine Interfaces (HMI) & Smart Control Panels
    • High-Resolution Smart Control Panels: Achieves smooth, complex UI gradients, transitions, and rotation effects on up to 720P LCD displays via PPA acceleration, 2D-DMA, and display driving capabilities, substantially reducing CPU usage during UI rendering.
    • Video Intercoms & Smart Doorbells: Combines a DVP camera interface, hardware JPEG encoding, and low-latency Wi-Fi 6 transmission to deliver real-time, high-definition video streaming and two-way audio intercom functionality.
  • Smart Home Gateways & Matter Border Routers (BR)
    • Multi-Protocol Hub Nodes: Simultaneously integrating Wi-Fi 6, Thread 1.4, Zigbee 3.0, and Bluetooth, it serves as an ideal single-chip solution for building Matter smart home gateways, Thread border routers, and multi-protocol local subnet hubs.
  • Industrial Automation & Edge Control Systems
    • Industrial Automotive & Telematics Gateways: Features an integrated CAN FD controller and Gigabit Ethernet MAC, making it ideal for industrial bus gateways, data acquisition terminals, or high-throughput sensor aggregators.
    • Complex Edge Computing & Lightweight Inspection: Runs lightweight OpenCV/YOLO models in industrial environments for object classification, color recognition, and status monitoring, utilizing 60 GPIOs to control a wide array of sensors and actuators.
Back to blog