The Espressif ESP-Mosaico is an expandable smart-interaction development kit based on the ESP32-S31 microcontroller. The compact device integrates a 2.16-inch square touch display, audio hardware, motion and magnetic sensors, NAND storage, haptic feedback and dual expansion interfaces for HMI, edge voice and multimedia applications.

The ESP32-S31NRV16 at the center of the board provides two 32-bit RISC-V cores operating at up to 320MHz and includes 16MB of in-package PSRAM. Wireless connectivity includes 2.4GHz Wi-Fi 6, Bluetooth 5.4 with Bluetooth Classic support, and IEEE 802.15.4 connectivity for Thread and Zigbee.

ESP32-S31 block diagram

For reference, the ESP32-S31 architecture provides 512KB of SRAM along with multimedia and connectivity peripherals including a JPEG codec, pixel-processing accelerator, LCD and camera controller, USB 2.0 High-Speed OTG, Ethernet MAC and CAN-FD controller. Espressif also lists SIMD acceleration on one of the processor cores.

ESP-Mosaico V1.0 block diagram

Storage includes 16MB of onboard SPI NOR flash in addition to the ESP32-S31’s 16MB PSRAM. A 1Gbit (128MB) SPI NAND device is provided for larger graphics, multimedia and other application assets.

The hardware is divided between a CoreBoard and a BaseBoard connected through a 60-pin board-to-board connector. The BaseBoard carries the speaker, a 3.7V 65mAh Li-ion battery and two 2 × 10-pin, 2.54mm-pitch expansion headers. These interfaces expose GPIO, UART, I2C, USB Serial/JTAG and power connections for add-on modules.

Coreboard front and back view

The ESP-Mosaico includes a 2.16-inch 480 × 480 display driven by a CO5300 controller over QSPI, while a CST9220-series controller handles touch input over I2C. The board also provides a programmable status LED and a dedicated application button.

Motion sensing is handled by a Bosch BMI270 six-axis IMU, accompanied by two BMM150 three-axis magnetometers. Espressif lists magnetic expansion toys, motion sensing and square-display HMI applications among the intended use cases for the development kit.

Baseboard front and back view

Audio hardware consists of an ES8311 low-power mono codec connected through I2S, an NS4150B 3W Class-D amplifier, an onboard microphone and a speaker. A vibration motor driven from GPIO8 provides haptic feedback.

Power and data are also available through a USB Type-C connector connected to the ESP32-S31’s USB 2.0 High-Speed OTG interface. The port supports firmware download, debugging and application communication in addition to charging the onboard battery. Espressif states that the port can operate as a 5V source for attached USB devices, with a specified maximum output of 500mA.

ESP-Mosaico V1.0 front and back view

Battery management includes a TP4057 charger and BQ27220 fuel gauge for monitoring voltage, current and state of charge. The board can alternatively be powered through its expansion interfaces.

Software development uses ESP-IDF with esp32s31 as the target. Espressif’s documentation lists an ESP-Mosaico board support package covering the display, touch controller, audio subsystem, sensors, battery management, NAND flash, USB console and module interfaces.

Specifications listed for the ESP-Mosaico include:

• Processor:
  • Espressif ESP32-S31NRV16
  • Dual-core 32-bit RISC-V at up to 320MHz
  • 16MB in-package PSRAM
• Storage:
  • 16MB SPI NOR flash
  • 128MB SPI NAND flash
• Wireless:
  • 2.4GHz Wi-Fi 6
  • Bluetooth 5.4 LE + BR/EDR
  • IEEE 802.15.4 for Thread/Zigbee
• Display:
  • 2.16-inch 480 × 480 QSPI touch display
  • CO5300 display controller
  • CST9220-series touch controller
• Sensors:
  • Bosch BMI270 6-axis IMU
  • 2x Bosch BMM150 3-axis magnetometers
• Audio and haptics:
  • ES8311 mono audio codec
  • NS4150B 3W Class-D amplifier
  • Onboard microphone
  • Speaker
  • Vibration motor
• I/O:
  • 2x 20-pin, 2.54mm-pitch expansion headers
  • GPIO, I2C, UART and USB Serial/JTAG
  • Back-side I2C and power expansion pads
• USB:
  • 1x USB Type-C
  • USB 2.0 High-Speed OTG
• Other Features:
  • Power button, Boot button
  • Function/AI button
  • Status, power and charging LEDs
  • Debug pads
• Power:
  • 3.7V, 65mAh Li-ion battery
  • TP4057 battery charger
  • BQ27220 fuel gauge
  • USB-C and expansion power input
• Mechanical:
  • 60-pin board-to-board connector

Further Information

The ESP-Mosaico is currently listed by third-party sellers on AliExpress for about $117, although official pricing and broader availability have not been announced.