Adafruit Metro RP2350 development board follows Arduino UNO form factor, features HSTX DVI output

The Adafruit Metro RP2350 is a Raspberry Pi RP2350 development board that closely follows the Arduino UNO form factor for compatibility with existing Arduino shields.

Key features include 37 GPIOs, a microSD card slot, a 5V buck converter (6–17V input), an onboard RGB NeoPixel, a Stemma QT port for I2C peripherals, a 22-pin HSTX port for DVI video output, and a USB Type-C port for power and data. It also provides a Pico Probe debug port, an RX/TX switch for UART flexibility, and a UF2 bootloader for easy firmware updates. Target applications include IoT projects, embedded system development, hardware prototyping, and educational purposes.

Adafruit Metro RP2350 specifications

• SoC – Raspberry Pi RP2350
  • CPU
    • Dual-core Arm Cortex-M33 @ 150 MHz with Arm Trust zone, Secure boot
    • Dual-core RISC-V Hazard3 @ 150 MHz
    • Up to two cores can be used at any given time
  • Memory – 520 KB on-chip SRAM
  • Security
    • 8KB of anti-fuse OTP for key storage
    • Secure boot (Arm only)
    • SHA-256 acceleration
    • Hardware TRNG
    • Fast glitch detectors
• Memory – 8 MB of QSPI PSRAM (optional)
• Storage
  • 16 MB of QSPI flash
  • MicroSD card slot (SPI interface, extra pins for SDIO)
• USB – USB Type-C for power and programming (USB Host breakout pads with controllable 5V power)
• Expansion
  • 37x GPIO
    • 23x on standard headers
    • 12x on HSTX FPC port
    • 2x for USB Host
  • 2x UART
  • 2x SPI
  • 2x I2C (Stemma QT port for I2C peripherals)
  • 24x PWM channels (compared to 16 on RP2040)
  • 12x PIO state machines
  • 22-pin 3-lane differential HSTX FPC port (Raspberry Pi 5-compatible pinout)
• Debugging – Pico Probe debug port (3-pin JST SH)
• Misc
  • Onboard RGB NeoPixel LED
  • Onboard #23 indicator LED
  • Reset and BOOT buttons
  • RX / TX switch for swapping D0 and D1 locations
• Power Supply
  • 6-17V DC input (5.5mm / 2.1mm barrel jack)
  • 5V buck converter (TPS563201)
  • On/off switch for DC power
• Dimensions – 68.6 mm x 53.4 mm

In terms of software, the Adafruit Metro RP2350 development board ships with a ‘permanent ROM’ USB UF2 bootloader which lets you easily program with CircuitPython. Other than that, it can also be programmed with C/C++ (RP2040 SDK), MicroPython, or an unofficial Arduino core. But Adafruit recommends CircuitPython for driver support for sensors, displays, and peripherals. One thing to remember is that in C/C++ development, the entire flash is available, while in MicroPython/CircuitPython, around 14MB remains for user files. Instructions to get started with the board can be found on Adafruit Learn.

In a short note, Adafruit also mentions that the board uses the A2 revision of the Raspberry Pi RP2350 SoC, which has an E9 erratum affecting GPIO pull-down resistors. This errata affects some uses of GPIO and PIO such as high-impedance inputs and the internal pulldowns. You may need to use 8.2K or smaller resistors if pull-downs are required. At this time, March 2025, there is no other version of the RP2350 available – only the A2 version.

The Adafruit Metro RP2350 is not the only Raspberry Pi RP2350 board with Arduino UNO form factor, but it’s the easiest to source. Alternatives include the open-source hardware RP2350-Eins which you’d need to build yourself, and the UNO RP2350 which we found in a Facebook post last January, but does not seem available yet.

The Adafruit Metro RP2350 development board can be purchased on Adafruit store for $24.95 without PSRAM, or $27.95 with PSRAM.

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