ESP32-S31-Zero: Waveshare's $10.99 Wi-Fi 6 RISC-V Board

Waveshare has squeezed Espressif's most capable wireless microcontroller into its tiny "Zero" form factor. The new ESP32-S31-Zero follows the footprint of earlier boards like the ESP32-S3-Zero, but upgrades to the dual-core RISC-V ESP32-S31 with Wi-Fi 6, Bluetooth 5.4 and an 802.15.4 radio for Thread, Zigbee and Matter. CNX Software spotted the board on November 7, and at $10.99 it is one of the cheapest ways yet to start building with this chip.

• ESP32-S31 RISC-V processor at up to 320 MHz with 512KB SRAM
• 2.4 GHz Wi-Fi 6, Bluetooth 5.4 LE and Classic, plus 802.15.4 for Thread and Zigbee
• 16MB or 32MB PSRAM and 16MB or 32MB SPI flash, on a 28 x 18mm board
• The N32R16 model costs $10.99 from Waveshare, $12.23 on AliExpress and $18.99 on Amazon

ESP32-S31-Zero Specs at a Glance

The board keeps the Zero family formula: a USB-C port for power and programming, castellated holes and through-holes along the edges exposing up to 15 GPIOs, UART and six ADC inputs, and a WS2812 RGB LED with Boot and Reset buttons. Power arrives over USB-C or a 5V pin and passes through an MP1605 step-down converter. Antenna options are an onboard 2.4 GHz ceramic antenna or an IPEX connector, depending on the version.

The big addition is a 40-pin high-density board-to-board connector. Because the ESP32-S31 has so many I/Os, Waveshare uses it to break out an RGB LCD interface, touchscreen signals, an SD card and USB 2.0. That makes this tiny development board far more capable than its size suggests.

Can the ESP32-S31-Zero Use Gigabit Ethernet?

Not out of the box. Like several other early ESP32-S31 boards, it does not expose the chip's Gigabit Ethernet MAC directly. However, CNX Software points out that the RGMII pins are multiplexed with GPIO8 through GPIO19, which are all reachable on the 40-pin connector. In principle, a small expansion board could add Gigabit Ethernet and turn this into a miniature IoT gateway combining wired networking, Wi-Fi 6, Bluetooth LE and Thread. That is a fun project waiting to happen.

Software Support and Availability

Waveshare's documentation covers ESP-IDF setup, firmware flashing and schematics, with 12 ESP-IDF examples spanning GPIO, the RGB LED, buttons, UART, I2C, Wi-Fi, Bluetooth LE, display, touch and SD card tests. The documentation lists eight variants mixing PSRAM, flash and pre-soldered headers, though CNX notes that only the N32R16 model, with 16MB PSRAM and 32MB flash, is available right now.

Why This RISC-V Microcontroller Board Stands Out

The ESP32-S31 has been arriving on bigger, display-centric boards, so a stamp-sized option for wearables, sensors and Matter devices is a welcome addition. Espressif's early work on Linux for the chip, covered in our story on the ESP32-S31 Linux BSP developer preview, adds long-term upside. Want a version with a screen? Our look at the ESP-Mosaico ESP32-S31 dev kit covers that. Browse more in our mini computers coverage.

Sources: CNX Software — November 7, 2026; Waveshare ESP32-S31-Zero documentation — accessed November 7, 2026; Waveshare store — accessed November 7, 2026.