Cube Red dual-controller autopilot module

The Cube Red dual-controller autopilot module from CubePilot is a flight controller for uncrewed aircraft and eVTOL platforms that need redundant processing and sensing. It pairs a primary and a secondary flight-control processor on one module, with multiple inertial units, barometers and a compass, and exposes CAN FD, Ethernet and USB connections to the vehicle.

Each of the two processors is an STM32H7-series microcontroller combining a Cortex-M7 core and a Cortex-M4 core, with a double-precision floating-point unit and embedded non-volatile flash. The primary controller also has external flash memory. Splitting the work across two independent controllers lets an integrator run a primary control channel and a secondary channel for monitoring or fallback, which is a common building block for fault-tolerant flight-control architectures in larger drones.

Sensing is redundant as well. The module carries four IMUs: three are wired to the primary controller and one to the secondary controller. Three barometers are fitted, two on the primary side and one on the secondary side, each with a 24-bit sigma-delta converter, a 10 cm altitude resolution and a measuring range of 10 to 1200 mbar. The compass has a field range of plus or minus 1100 microtesla, 13 nT sensitivity and 15 nT noise. For the airframe designer this means several independent measurements of attitude, acceleration and altitude can be compared in software to detect a failing sensor.

Pressure measurement is protected mechanically. The module has an isolated static air port, a replaceable closed upper lid and isolated static air ducts, which keep the pressure seen by the barometers stable. Foam inserts of different hardness are available so the vibration damping can be matched to the vehicle.

Connectivity is built around three CAN FD ports: one tied to the primary controller, one to the secondary controller, and one shared by both so that either can keep a bus alive if the other fails. The transceivers support data rates of 2, 5 and 8 Mbps, are specified to ISO 11898-2, suit 12 V and 24 V systems and operate from minus 40 to plus 150 degrees Celsius. Beyond CAN FD, the module offers USB full speed compatible with a USB Type-C connector, 10/100BaseT Ethernet and a Display Serial Interface.

Typical applications are the avionics core of heavy-lift multirotors, fixed-wing and VTOL uncrewed aircraft and small eVTOL demonstrators, where networked smart peripherals such as ESCs, GNSS receivers, radios and payloads share a CAN FD backbone and where Ethernet links a companion computer or ground equipment.