The just-announced Moddo Pinch board is a 10.9 × 10.5 mm Arduino-compatible development board built around Microchip’s ATSAMD11D14A microcontroller. Toronto-based Moddo claims it is the world’s smallest 32-bit Arduino-compatible board, and it does manage to fit native USB-C, an RGB LED, a reset button, and a regulator onto a PCB barely larger than the connector itself.

For scale, the familiar Arduino Nano RP2040 Connect measures 45×18 mm. Pinch is not intended to match the Nano’s processing power or memory; its attraction is putting enough Arduino functionality into projects where even a conventional small development board is physically awkward.

Moddo Pinch Board Hardware

The 32-bit Arm Cortex-M0+ core runs at up to 48 MHz, with 4 KB of SRAM and 16 KB of flash. The bootloader occupies 4 KB, leaving approximately 12 KB for sketches. That is modest even by microcontroller standards, but sufficient for compact controllers, sensor interfaces, wearable electronics, and USB human-interface devices.
 

Pinout diagram for the Moddo Pinch Arduino-compatible board, showing its USB-C connector, 10.9 × 10.5 mm dimensions, GPIO assignments, power pins, analog inputs, SPI, I²C, UART, reset button, and RGB LEDs.
The Moddo Pinch pinout includes 12 exposed GPIO connections, five analog inputs, SPI, I²C, two UART interfaces, reset control, and three addressable LED channels.
  • 12 header-accessible GPIO pins, with 15 GPIOs in total
  • Five analog inputs, 11 PWM outputs, and one true DAC output
  • I²C, SPI, and two UART interfaces
  • Native full-speed USB-C supporting CDC serial and HID
  • A 16-pin, 1.27 mm-pitch expansion header
  • 5 V USB power with up to 500 mA output and a 3.3 V LDO rated for up to 300 mA
 

The fine-pitch header is the inevitable tax on making the board this small. Moddo therefore offers a breakout PCB that converts the connections to the more breadboard-friendly 2.54-mm pitch. SWD debugging is also available through D5 and D6, although those pins are shared with the secondary UART.

Programming the Moddo Pinch Board

The Moddo Pinch board uses a custom Arduino SAMD package, with the board definition and documentation available on GitHub. Programming is handled directly over USB-C, without an external programmer. A double tap on the reset button forces the board into its bootloader if a sketch disables USB or otherwise prevents a normal upload.

The software exposes options for USB operation, oscillator calibration, PWM frequency, and floating-point formatting. Those choices matter on a device with only 12 KB available for application code. The default USB configuration supports CDC serial and HID, but the implementation allows only one HID interface. A combined keyboard-and-mouse device is possible; stacking unrelated HID classes is not.

Moddo design and hardware lead Justin Kim said the board had reached final testing and mass production. The same early report noted that its attempt to install the Boards Manager package did not complete. That may be fixed well before hardware ships, but it is a reminder that Pinch is still a prerelease platform rather than a mature ecosystem.

Price, Kit, and the Size Claim

The US$15.90 preorder kit includes the Pinch board, a 2.54-mm breakout board, and three unsoldered male headers. Shipping is scheduled to begin in September 2026.

The “world’s smallest” label needs the usual footnote. The older ATTO board measures 11.5×10.3 mm but uses an 8-bit ATmega32U4. The experimental RP2040-based RPDot is smaller at 10×10 mm, but it lacks USB-C and was not commercialized. In practical terms, Moddo’s claim is best read as the smallest commercially offered 32-bit Arduino-compatible board with onboard USB-C. That is still a fairly specific record, but for miniature HID devices, wearables, and cramped embedded builds, it is the specific part that counts.

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