Espressif's new ESP32-S31 is a microcontroller that comes with a surprisingly rich set of features more commonly found on single-board computers. It packs a 1000 Mbps Ethernet MAC via an 8P8C (RJ45) connector using RGMII, a USB 2.0 High-Speed OTG controller with a full-size Type-A socket, dual SD card slots, and a DVP camera interface supporting 8 to 16 bits. Additional peripherals include a parallel LCD controller, two I2S controllers with Bluetooth audio sync, fourteen capacitive touch channels, a CAN FD controller, and four MCPWM units.

On the CPU side, the ESP32-S31 features two 32-bit RISC-V cores running at up to 320 MHz, each with a floating point unit and 32KB of L1 instruction cache, sharing 64KB of data cache. A separate 40 MHz low-power core handles background tasks. Memory support includes up to 64MB of PSRAM and 256MB of flash, with the PSRAM interface now separate from flash.

The most significant change is the inclusion of a true MMU supporting Sv32 two-level page-table translation and Machine, Supervisor, and User privilege modes, enabling native Linux support. Espressif has already released a Linux BSP based on Buildroot and U-Boot, and the community has ported Linux 6.18 with working drivers. While not yet recommended for production, the ESP32-S31 represents a major leap toward SBC-level capabilities on a microcontroller platform.