Piunora is a compact and easy-to-use development platform for building electronics prototypes with Linux. It has a familiar form factor, clearly readable pin markings, and a design that fits well in tight applications. As a carrier board for the Raspberry Pi Compute Module 4 (CM4), Piunora is essentially a small-form version of the Raspberry Pi 4 Single Board Computer (SBC) with added flexibility for customizing enclosure layouts.

It includes an HDMI port, camera input connectors and PCI-e support, not all of which are present on a standard Raspberry Pi 4. The M.2 B-Key port on the back of the board is useful not only for SSD storage but can also host a variety of PCI-e expansion cards. It should be noted that Piunora is open hardware and is fully compatible with the Raspberry Pi CM4, provided the software accounts for the peripherals in use. This lets you leverage the ecosystem’s large collection of existing drivers and makes developing embedded applications with Piunora as easy as possible.

Piunora is an ideal solution for working with electronics; it includes Qwiic/Stemma QT-compatible connectors developed by Adafruit and SparkFun for connecting hundreds of high-quality sensors quickly and easily in a daisy-chained I2C fashion via Python. The board includes a Type-C port that can support power and USB 2.0 data transfer. It consumes less power than a full-size Raspberry Pi 4 and can be programmed directly with CircuitPython via a compatibility layer — Adafruit Blinka — on Linux SBCs. Additionally, there is an M.2 connector that provides a compact-style connection for add-on boards, meaning it can be used to develop a simple, space-efficient, USB-compatible MCU solution.

Features

• Strong compatibility: Fully compatible with software written for the Raspberry Pi 4.
• PCI-e via M.2 B-Key connector on the back of the board, with its own 3.3 V / 3 A supply.
• Analog-to-digital converter (MCP3008)
• On-the-fly switch between USB host (USB Type-A) and device (USB Type-C) modes.
• Qwiic/Stemma QT connector enabling easy connection to I2C devices.
• Full-size camera connector supporting all Pi-compatible cameras
• Full-size HDMI 2.0 connector
• WS2812 Smart RGB LED for user status.
• Optional Wi‑Fi or eMMC options depending on CM4 selection.
• Two user-controllable buttons: Includes firmware that converts each into a safe-shutdown button.

Applications

• Developing projects with Raspberry Pi
• Hacking and integration
• Embedded machine learning applications
• Daisy Chain Topology applications

Documentation

• Wiki - Piunora Raspberry Pi CM4 board
• USB switch
• Getting Blinky working with Blinka (Python)
• USB Gadget
• Heatsink assembly
• Shutdown button
• Using Qwiic/Stemma QT (I2C)
• Case and feet
• Analog-to-digital converter
• RGB LED