Adafruit Metro ESP32-P4 Hydra pairs RISC-V MCU with WiFi 6, MIPI display and camera interfaces

Adafruit has released the Metro ESP32-P4 Hydra, a development board that maintains the Arduino UNO form factor while using Espressif's newer ESP32-P4 RISC-V microcontroller as its primary compute element. The board pairs the ESP32-P4 with a separate ESP32-C6 module handling wireless connectivity, including WiFi 6, Bluetooth 5.3 LE, Thread, and Zigbee. Notable I/O additions over typical ESP32 boards include 2-lane MIPI DSI and CSI connectors in the Raspberry Pi 22-pin format, enabling direct attachment of touch displays and camera modules without additional bridge hardware.

The ESP32-P4 v1 chipset provides a dual-core 360 MHz RISC-V application processor with AI instruction extensions, a separate 40 MHz low-power RISC-V core, 768 KB of L2 memory, and 16 MB each of PSRAM and QSPI NOR flash. The board also integrates a USB 2.0 High-Speed host port, microSD slot, STEMMA QT connector, LiPo charging, and multiple power input options. Software support currently includes Espressif's ESP-IDF, TinyUF2 drag-and-drop firmware updates, and early alpha-level CircuitPython 11.0.0-alpha.2 integration, with Arduino IDE support in development.

ESP32-P4 architecture and I/O configuration

• Dual-MCU architecture: The ESP32-P4 handles application processing while the ESP32-C6 manages all wireless via SDIO, isolating radio firmware from the main RISC-V cores and allowing independent power management of the connectivity subsystem.
• MIPI interface implementation: The board exposes 2-lane MIPI DSI and CSI through Raspberry Pi-compatible 22-pin, 0.5mm-pitch connectors, supporting the 720x1280 Raspberry Pi Touch Display 2 in 5-inch and 7-inch variants and OV5647-based camera modules, though not the newer IMX708 Camera Module 3.
• Memory and acceleration: 16MB PSRAM supplements the 768 KB HP L2MEM, while the 2D Pixel Processing Accelerator (PPA) and H.264/JPEG VPU provide hardware-accelerated graphics and video encoding without requiring external DSP or GPU silicon.
• USB host capability: A dedicated USB 2.0 Type-A port runs at 480 Mbps with software-controlled power switching and a 5V boost supply, enabling direct attachment of USB peripherals such as keyboards, storage, or additional radios.
• Power flexibility: The board accepts 7-12V DC, USB-C, or single-cell LiPo with onboard charging and voltage monitoring, targeting battery-operated IoT and portable HMI deployments.

Why it matters

The Metro ESP32-P4 Hydra fills a gap between low-end ESP32 IoT modules and Linux-capable SBCs by offering MIPI display and camera interfaces on a sub-$35 board with Arduino-compatible physical expansion. For embedded developers and open hardware designers, this provides a migration path from ESP32-S3 designs to the P4's RISC-V architecture and AI instruction set without abandoning existing Arduino shields or Adafruit's STEMMA ecosystem. The early CircuitPython alpha and in-progress Arduino support indicate the broader open-source embedded tooling community is beginning to adopt the ESP32-P4, though production deployments will need to wait for software maturity.