Rook v1.2 Avionics Board

Overview

Rook is a combined onboard computer (OBC), command-and-data-handling (C&DH) system, and electrical power system (EPS) for CubeSat development and flight applications. It provides the flight processor, power management, storage, sensors, deployment control, payload interfaces, and a dedicated radio interface on a four-layer board.

Rook substantially redesigns the PyCubed hardware while retaining its familiar CircuitPython software model.

Technical Specifications

Description

Rook is Blackwing Space’s integrated flight avionics board, combining onboard computing (OBC), command and data handling (C&DH), and electrical power management in a compact CubeSat-ready architecture. A single four-layer board integrates the flight processor, power management, persistent and removable storage, onboard sensing, deployment control, payload interfaces, and a dedicated radio interface.

Built around a 120 MHz Arm Cortex-M4F, Rook provides 1 MB of onboard flash, 512 KB of persistent MRAM, and microSD storage for mission and payload data. It supports CircuitPython or embedded C, giving developers a fast, accessible path from benchtop development to flight software. Rook evolved from the PyCubed architecture, retaining its approachable software model while substantially redesigning the hardware for Blackwing’s modular nanosatellite platforms.

What it handles

• C&DH - flight-software execution, task scheduling, operating modes, telemetry, command handling, watchdog recovery, and subsystem control.
• EPS - solar and USB charging, battery management, regulated power rails, input protection, and voltage/current telemetry.
• Storage - MRAM for persistent state, QSPI flash for software and telemetry, and microSD for mission or payload data.
• Payload interface - power, I2C, SPI, UART, and GPIO through a 40-pin Samtec board-to-board connector.
• Radio interface - power, SPI, reset, programming, and control through a dedicated 20-pin Samtec connector, with a separate SMP RF connection.
• Deployment - high-current burn-wire drivers with hardware relay inhibit.
• Navigation and sensing - BNO086 inertial sensor, with GNSS receiver and antenna provision.

Core specification

• Processor - Microchip ATSAMD51J20A, 32-bit Arm Cortex-M4F, up to 120 MHz.
• Memory - 1 MB internal flash, 256 KB SRAM.
• Persistent state - Everspin MR25H40 MRAM, 4 Mbit (512 KB).
• Bulk storage - Winbond W25Q128 NOR flash, 128 Mbit (16 MB).
• Removable storage - microSD interface.
• Software - CircuitPython 10 or embedded C.
• Bootloader - ROOKBOOT, in the protected 16 KB BOOTPROT region.
• Watchdogs - SAMD51 internal and MAX706 external.
• Sensing - BNO086 nine-axis IMU with onboard sensor fusion.
• PCB - four-layer FR-4, approximately 90.2 × 95.9 mm.

Electrical power

• Charge controller - TI BQ25798 buck-boost.
• Power inputs - solar and USB-C.
• Battery support - one to four lithium-ion cells.
• Charge current - software-programmable, up to 5 A.
• Solar isolation - six LTC4412 ideal-diode PowerPath controllers.
• Regulated rails - 3.3 V and two 5 V rails.
• Radio PA rail - switched 11 V boost supply.
• Low-noise rail - LT3045-regulated RF/GNSS supply.
• Protection - TPS259470 eFuse, physical fuses, TVS protection, zener clamps, and battery protection FETs.
• Telemetry - input, battery, and system voltage and current monitoring.

Radio options

• Warbler UHF radio - OpenLST-derived, on the dedicated 20-pin Rook radio interface.
• Hummingbird LoRa radio - packet, telemetry, ground-station, and RF-link development. (Available Q3 2026)

Key Benefits

• Three subsystems on one board - OBC, C&DH and EPS together - flight processor, power management, storage, sensors, deployment control and payload interfaces on a single four-layer board.
• Useful before you have a spacecraft - The board runs on a workbench over USB with no battery, radio, antenna or flight stack attached, so bring-up and software work start immediately.
• The radio is a choice, not a commitment - Develop with no radio, a LoRa development radio, or the Warbler UHF module. Separated mission, protocol, comms-manager and driver layers mean simulated or LoRa work moves to Warbler without a rewrite.
• Plug-and-play payload integration - A single 40-pin Samtec connector replaces PyCubed's four soldered payload locations, so integration is standardised and repeatable instead of custom solder work.
• Room for real flight software - 1 MB flash and 256 KB SRAM against PyCubed's 512 KB and 192 KB leaves headroom for more drivers, more payload processing and more comms buffering.
• Storage that does not compete - 16 MB of QSPI flash takes bulk software and telemetry, freeing the 512 KB MRAM to hold persistent system state exclusively.
• Charge from USB or solar - The BQ25798 dual-input controller accepts whichever source is available, and resolves the PyCubed fault where shaded opposing panels could backfeed and drain the pack.
• Layered electrical protection - eFuse, physical fuses, TVS, zener clamps, battery protection FETs, ideal-diode solar isolation and hot-swap I2C buffers that recover a stuck bus.
• Choose Python or C - CircuitPython 10 for rapid iteration, or embedded C for tighter hardware control and stronger fault tolerance. Prototyping in Python then converting to C for flight is a proven path.
• Recovery that does not depend on the filesystem - ROOKBOOT runs first after every reset from a protected flash region a corrupted image cannot touch, and pairs with an MRAM backup image for autonomous in-flight recovery.
• A complete teaching platform - One board covers bring-up, flight software, communications, payload development and ground systems - sensor to payload controller to Rook to radio to ground station to dashboard.

Support & Warranty

The 40-pin payload interface is documented in full on the Sparrow Developer Platform — Payload Interface Guide with the complete pinout, STEP template, GD&T drawings and DXF outline. The payload software interface specification is in development.

That interface can be developed against on the bench before flight hardware exists using the Hardware Dev Kit, which pairs a Rook 1.2 Lite board with a Dodo Lite payload board across the same connector used in flight.

Radio, battery, antenna, payload hardware, harnesses and mission software depend on the purchased configuration. Engineering support is available for integration, firmware and mission planning questions — reach the team at hello@blackwingspace.com.