Espressif has built one of its most feature-dense development boards yet around the ESP32-S31, its dual-core RISC-V microcontroller that brings Wi-Fi 6 and Bluetooth 5.4 to the ESP32 family. The ESP-Mosaico pairs the new chip with a 5.5 cm (2.16-inch) 480 x 480 capacitive touch display, a Bosch BMI270 six-axis IMU, dual BMM150 magnetometers, an audio subsystem with microphone and speaker, and a vibration motor for haptic feedback, all on a board small enough to fit in a palm. Developed under ESP-IDF with a published board support package, the kit is aimed at edge voice, HMI, and multimedia prototyping.

The ESP32-S31NRV16 at the core runs two 32-bit RISC-V cores at up to 320 MHz, with SIMD acceleration on one core and 512 KB of SRAM alongside 16 MB of in-package PSRAM. Wireless connectivity covers 2.4 GHz Wi-Fi 6, Bluetooth 5.4 with both LE and Classic support, and IEEE 802.15.4 for Thread and Zigbee, making it a natural fit for Matter-based smart home projects. The SoC also integrates a JPEG codec, a pixel-processing accelerator, LCD and camera controllers, USB 2.0 High-Speed OTG, a Gigabit Ethernet MAC, and a CAN-FD controller, according to Espressif.

The Mosaico itself splits into a CoreBoard and BaseBoard linked by a 60-pin connector. The CoreBoard carries the ESP32-S31 module, display, and sensors, while the BaseBoard holds a speaker, a 3.7 V 65 mAh Li-ion battery with TP4057 charger and BQ27220 fuel gauge, and two 2 x 10-pin 2.54 mm expansion headers. Those headers expose GPIO, UART, I2C, USB Serial/JTAG, and power lines, so camera modules and other add-ons can slot in without soldering. A USB Type-C port handles firmware flashing, debugging, data, and charging, and can also supply 5 V at up to 500 mA to attached peripherals.

On the software side, the ESP32-S31 is supported by ESP-IDF 6.1 and the current master branch, along with ESP-Matter for smart home device development. Arduino core support is available as a 4.0.0-RC1 pre-release built on ESP-IDF 6.1. Storage on the Mosaico includes 16 MB of SPI NOR flash for firmware and a 128 MB SPI NAND chip for larger assets like graphics and audio. The board's audio chain pairs an ES8311 mono codec over I2S with an NS4150B 3 W Class-D amplifier, making it a reasonable starting point for voice assistant or edge audio experiments.

Mosaico-specific open-source tooling has grown up around the board on GitHub under the esp-mosaico organization. Its esp-mosaico-bsp repository builds on ESP-IDF 6.1+ to provide a unified API for the display, touch controller, audio codec, sensors, storage, power management, and the two expansion headers, plus reusable components for magnetic device-to-device interaction and ESP-NOW messaging. A companion project, esp-mosaico-vibe, sets up a workflow for AI coding agents to flash and exercise firmware directly on physical Mosaico hardware, feeding device logs and display output back into the agent's edit loop.

Linux itself runs on the ESP32-S31 chip, though not yet on the Mosaico's own display and sensor set. Espressif published a developer-preview Linux BSP for the ESP32-S31 in August 2026, combining Buildroot 2025.02 with a Linux 6.18 kernel fork, U-Boot, and a device tree, and explicitly labeled it unsuitable for production use. Community developers have carried that further on other ESP32-S31 boards: GrieferPig's port gets an MMU-enabled RV32 Linux 6.12 build running natively on the chip, and other forks have booted newer kernels with working display, storage, and networking drivers. So far, that porting work targets the ESP32-S31-Korvo-1 and Function-CoreBoard-1 devkits rather than the Mosaico, so a maker wanting to run Linux on this particular board would still be doing pioneering work of their own.

The ESP-Mosaico is currently available from third-party sellers at roughly $117 (€108), though Espressif has not announced official pricing or broader retail availability.