This board is designed as a drop-in replacement for the classic Arduino Pro Micro (ATmega32U4), but powered by the modern Raspberry Pi RP2350A microcontroller.
It keeps the same form factor and pinout while offering massive improvements in performance, memory, and connectivity — making it the ideal choice for Mobiflight cockpits.

• Identical footprint & pinout to the Arduino Pro Micro
• Works with existing wiring and PCB layouts → no hardware redesign required

• Dual-core ARM Cortex-M33 @ up to 150 MHz (with FPU & DSP)
• Handles many encoders, switches, LEDs, and displays simultaneously
• 512 KB SRAM + up to 16 MB Flash → no memory limits for complex setups

• Native USB 2.0 FS/HS

• 5V-tolerant I/O pins → safe with legacy 5V sensors, LEDs, and modules
• Fully compatible with most cockpit electronics

• ARM-based low-power modes for large setups
• Stable & future-proof, backed by Raspberry Pi Foundation support

While this board is highly compatible, there are a few important differences:

1. Analog Inputs

   • Only A0 to A3 are available (4 total)
   • Other analog pins present on the Pro Micro are not supported

2. 5V Output (Pin 21)

   • On the Arduino Pro Micro, Pin 21 outputs 5V
   • On this board, Pin 21 outputs 3.3V

3. MAX7219 & 5V Requirement

   • The MAX7219 driver must still be powered with 5V
   • Therefore, an external 5V source is required, or you can use Pin 24 (Vin), which provides 5V directly from the USB connector

4. Level Shifting for MAX7219

   • The MAX7219 requires 5V logic levels
   • Use a level shifter between the PicoMicro board (3.3V signals) and the MAX7219 inputs

5. Bootloader Button

   • The board includes a dedicated BOOT button to enter USB mass storage boot mode (for firmware flashing).

When using a MAX7219 with this PicoMicro board, note the following:

• The MAX7219 requires 5V power for reliable operation.
• The PicoMicro board only provides 3.3V logic, so a level shifter is required on the SPI signals.
• Use the Vin pin (Pin 24, USB 5V) as the 5V source if no external supply is available.
• Do not use Pin 21 (5V), as it only provides 3.3V on this board.

• Vin (5V USB) → VCC (5V MAX7219)
• GND → GND
• MOSI (3.3V) → (via level shifter) → DIN (5V)
• SCK (3.3V) → (via level shifter) → CLK (5V)
• CS (3.3V) → (via level shifter) → LOAD/CS (5V)

Make sure to add a 3.3V → 5V level shifter on the SPI signals to the MAX7219.

Many Mobiflight Custom Devices (Community Devices) are more complex and require more memory and processing power than the classic Arduino Pro Micro can provide.
This board with the RP2350A offers clear advantages:

• More Flash → room for larger device code and libraries.
• More RAM → essential for OLED displays and complex buffers.
• Higher performance → smoother updates and faster response.
• Dual-Core CPU → allows splitting tasks (e.g., handling displays and inputs in parallel).
• PIO offload → precise timing for LEDs, drivers, or custom protocols

This makes the PicoMicro board especially well-suited for community-driven Mobiflight devices, including setups with OLED displays and other resource-demanding modules.

• Supports more devices per board → fewer boards, fewer USB connections
• Fast response times → smoother input/output handling with no lag
• Drop-in compatibility → works in place of the Pro Micro in your cockpit modules
• Future-ready → while the ATmega32U4 reaches its limits, the PicoMicro provides plenty of headroom for upcoming Mobiflight features

The PicoMicro is a next-generation upgrade built for Mobiflight cockpit builders:
✅ More performance & memory
✅ 5V-tolerant IO
✅ 100% ProMicro form factor
✅ Ideal for complex community devices, including OLEDs

Upgrade your cockpit today — with transparent compatibility notes for a smooth migration.