ESP-Mosaico: First Look at an ESP32-S31 Square-Screen Kit

ESP-Mosaico is the first development kit built around Espressif's ESP32-S31, and it packs a surprising amount into a square, wearable-sized package. Reported by LinuxGizmos on September 26, 2026, the board pairs the dual-core RISC-V microcontroller with a 2.16-inch touch display, motion sensors, audio and a small battery. Espressif's documentation lists it as board version 1.0 with a full board support package.

• The ESP32-S31 runs two 32-bit RISC-V cores at up to 320MHz with 16MB of in-package PSRAM.
• Storage is split between 16MB of SPI NOR flash and 128MB of SPI NAND flash.
• Radios cover Wi-Fi 6, Bluetooth 5.4 and IEEE 802.15.4 for Thread and Zigbee.
• It is listed for about $117 from AliExpress resellers; official pricing is not yet announced.

What is ESP-Mosaico?

Think of ESP-Mosaico as a reference design for the kind of device the ESP32-S31 was built for: an interactive, connected gadget with a screen. Our ESP32-S31 announcement coverage explained why this chip is Espressif's most capable wireless MCU yet, and developers have already shown it booting Linux on its 16MB of PSRAM. This kit is the easiest way to put that silicon on a desk.

The square 480x480 QSPI touch display uses a CO5300 controller with CST9220-series touch input; LinuxGizmos describes the panel as AMOLED. Espressif's own use-case list points to magnetic expansion, motion sensing and square touch interfaces.

ESP32-S31 sensors, audio and expansion

The sensor loadout is generous for a microcontroller board. A Bosch BMI270 6-axis IMU handles motion, and two Bosch BMM150 3-axis magnetometers add orientation sensing. Audio runs through an ES8311 mono codec and an NS4150B 3W Class-D amplifier, with an onboard microphone, speaker and a vibration motor for haptic feedback.

Expansion comes through two 20-pin, 2.54mm-pitch headers that expose GPIO, I2C, UART and USB Serial/JTAG. Power comes from a 3.7V 65mAh Li-ion cell with a TP4057 charger and a BQ27220 fuel gauge, so firmware can report accurate battery levels.

Who should consider the ESP-Mosaico dev kit?

Makers building smart-home controllers, compact dashboards, fitness gadgets or voice-enabled widgets get display, sensors, audio and three radio standards on one board. The 802.15.4 radio is the notable addition for Matter-over-Thread projects. Software support runs through ESP-IDF with a board support package covering the display, audio, sensors and peripherals.

If you are still choosing a chip family, our ESP32 variant buyer's guide compares the options. The roughly $117 reseller listing is a discount from $166.79, and Espressif has not announced official pricing or broader availability, so early buyers may want to wait for first-party stock. More SBC and microcontroller news lives in our mini computers section.

Sources: LinuxGizmos: ESP-Mosaico places dual-core RISC-V ESP32-S31 behind a 2.16-inch square AMOLED — September 26, 2026; Espressif ESP-Mosaico user guide — accessed September 28, 2026 (vendor documentation).