Onboard autonomy
Building an AI research drone: integrating a companion computer with Pixhawk
The hard part of putting a Jetson or a Raspberry Pi on an aircraft is not getting the two computers to talk. It is deciding what each one is allowed to be responsible for, and then making sure the one running experimental code cannot take the other down with it.
Draw the responsibility split before you buy anything
The autopilot keeps everything that has to work for the aircraft to remain flyable: attitude and position control, arming logic, geofence, failsafe behaviour, the RC link and the motor outputs. The companion computer gets the work that is valuable but not flight-critical: camera and sensor processing, detection, mapping, path planning, payload control and data recording.
The test to apply to every function you are about to move across is simple. If the companion computer stops responding mid-flight, what happens? If the honest answer is that the aircraft falls out of the sky, the split is wrong. A research platform should be able to lose its companion computer entirely and continue on the autopilot's own failsafe — hold position, return, or land, depending on what you configured.
This matters more on a research aircraft than on a production one, because the code on the companion computer is the code being developed. It will crash, it will hang, it will consume all available memory at an inconvenient moment. Design for that as the normal case, not the exception.
The link: serial for most projects, Ethernet where the data justifies it
The common path is MAVLink over a serial connection between one of the autopilot's telemetry ports and a UART on the companion computer. It is well supported by both PX4 and ArduPilot, and by the standard MAVLink libraries on the companion side. Three details decide whether it works: the port you use and its configured baud rate, the logic level, and flow control.
Logic level is the one that damages hardware. Pixhawk telemetry ports are 3.3 V logic. Connecting them to anything at 5 V without level shifting risks the autopilot, and a level-shifting adapter is cheaper than the controller. Cross the transmit and receive lines, share a ground, and set the same baud rate at both ends.
Raise the baud rate and the telemetry stream rates deliberately rather than leaving the defaults, which are tuned for a radio link and are conservative for a wired one. If your application needs high-rate state — a controller running at tens of hertz, or precise timestamping — that is where the serial route starts to strain, and where an Ethernet-capable baseboard and a modern DDS-based interface earn their extra complexity. Choose that route because the data rate requires it, not because it sounds more modern.
Source: PX4 companion-computer connection · PX4 1.16 Pixhawk Jetson baseboard setupPower: never take the companion computer off the autopilot's rail
This is the most common integration failure and it is entirely avoidable. The regulated supply on a flight controller is sized for the controller and its peripherals. A companion computer under load is a different class of consumer — and worse, a spiky one, because current draw jumps when the processor and its accelerator come out of idle.
Give the companion computer its own regulator from the battery, sized for its peak draw rather than its typical draw, and tie the grounds together so the serial link has a common reference. Then look at what happens at power-up: a companion computer's inrush at boot, on a shared supply, is a classic cause of a flight controller that resets exactly when you power the aircraft on the bench and never at any other time.
Two things to add to the electrical drawing. Which loads pass through the power module's current sensor — if the companion computer is fed separately, the autopilot's consumption display no longer describes the whole aircraft, and your endurance estimate is wrong. And a defined power-up order, if either device needs one, written on the checklist rather than remembered.
Source: Pixhawk Jetson baseboard overview and specification · PX4 companion-computer connectionMounting, vibration and the cooling problem nobody budgets for
Mount the companion computer so its mass is not hanging off the autopilot's vibration isolation. The autopilot is isolated to protect its IMUs; adding a heavy board to that isolated mass changes its resonant behaviour, and the symptom is a position estimate that degrades as the payload grows.
Cooling is the part that gets discovered in flight. A single-board computer running a vision workload dissipates real power, and an airframe's electronics bay is often a sealed box in still air — the bench test in an open lab at 22 °C tells you nothing about a closed bay in the sun at 38 °C. Thermal throttling does not announce itself: the aircraft flies normally and the frame rate quietly halves.
Plan a thermal path deliberately: a heatsink, ducted airflow, or a metal mounting plate conducting into the frame. Then verify it under load, in the enclosed bay, at the ambient temperature you actually operate in. And log the processor's own temperature and clock alongside your application's frame rate, so a throttling event is visible in the data rather than inferred from a bad result.
A baseboard that carries both, or two boards and a harness
Because the Pixhawk 6X-class controllers are compute modules on a separate baseboard, one of the baseboard options can carry the companion computer as well. Our catalogue lists a Jetson baseboard and an RPi CM4 baseboard, both in the group Holybro publishes for the 5X, 6X, 6X-RT and 6X Pro modules.
The integrated route removes the hand-built harness between two separately mounted boards, which is where intermittent faults live, and it fixes the mechanical relationship between the two computers so it cannot be got wrong on reassembly. The cost is that the pairing is now decided: changing the companion computer means changing the baseboard.
The separate route — a Standard Baseboard or Mini Baseboard plus an independently mounted carrier — keeps both choices open and lets you mount each where the airframe wants it. That is usually the right answer while the payload is still being decided, and the integrated route the right answer once it has settled. Either way, the module and the baseboard are two line items on the order.
If the aircraft itself is not yet chosen, the development kit range is a reasonable starting airframe — but read the kit name carefully, because it names the autopilot and radio variant included, and a kit is not a companion-computer solution on its own.
Source: Pixhawk Jetson baseboard overview and specification · Pixhawk RPi CM4 baseboard overview · Pixhawk RPi CM4 baseboard connections and portsThe bench-test checklist, before it leaves the ground
Run all of this with the propellers off and the propulsion made safe. Every line is something that has been found on a bench and would have been found in the air instead.
1. Link up. The companion computer receives the autopilot's heartbeat, and the autopilot sees the companion as a connected system. 2. Read and write. Read a parameter and receive the stream rates you configured, at the rate you configured them. 3. Command path. Send whichever offboard or guided command your application uses and confirm the autopilot accepts it and reports the mode it entered.
4. Failure of the companion. Power the companion computer off mid-session and confirm the autopilot behaves as configured, does not reset, and that its logs record the loss. Then kill your application process rather than the power, and confirm the same. 5. Failure at power-up. Power-cycle the whole aircraft ten times and confirm the flight controller never resets on the companion's boot inrush.
6. Thermal soak. Run the real workload in the closed bay for longer than your intended flight, logging processor temperature and clock, and confirm no throttling. 7. Vibration. With everything mounted as flown, check the autopilot's vibration levels against the flight stack's own guidance before and after adding the companion computer.
8. Record the configuration. Firmware versions on both sides, autopilot parameters changed, baud rate and port, the companion's operating-system image and your application's commit. A result you cannot reproduce because you cannot say what was running is not a result.
What to send with an enquiry
The autopilot model and baseboard, or that you need both selected; the companion computer you intend to use, or the workload if you have not chosen one; the interface you want between them; the battery voltage and the companion's peak current draw; the space available in the electronics bay with a rough sketch; and your operating ambient temperature.
That last one is worth including even though it feels unrelated to a parts list. It is what decides whether the answer is a heatsink or a duct, and it is much cheaper to design in than to discover.
Ways to put a companion computer next to a Pixhawk
All five baseboards below are listed for the same module family, so this is a genuine choice rather than a compatibility constraint. What separates them is how much of the integration is done for you, and how much freedom you keep.
| Route | Holybro SKU | Companion computer | What you still specify |
|---|---|---|---|
| Jetson baseboard, with case | 11072A | NVIDIA Jetson, on the same board | Jetson module, storage, cooling |
| Jetson baseboard, no case | 11072 | NVIDIA Jetson, on the same board | Enclosure, Jetson module, storage, cooling |
| RPi CM4 baseboard | 18080 | Raspberry Pi CM4, on the same board | CM4 variant (RAM and eMMC), storage, cooling |
| Standard Baseboard V2B | 18125 | Separate, your choice | Companion board, carrier, mounting, harness, power |
| Mini Baseboard | 18074 | Separate, your choice | As above, in less space |
Part numbers and the module family each baseboard serves are from the Holybro price list held in this catalogue. Connector counts, board dimensions, supported Jetson and CM4 variants and thermal design guidance are revision-dependent — take them from Holybro's documentation for the exact SKU quoted. The autopilot module is a separate line item on every row.
Source: Pixhawk Jetson baseboard overview and specification · Pixhawk Jetson baseboard dimension and weight · Pixhawk RPi CM4 baseboard overview · Pixhawk RPi CM4 baseboard connections and portsWhat each computer is responsible for
Draw this for your own aircraft before you write any code. The line down the middle is a design decision, and the two power paths at the bottom are what stop a crash on one side becoming a crash on the other.
Products discussed
The parts this guide names.
Specifications on each page are the manufacturer's. Confirm the exact variant and document revision before ordering.
Pixhawk Jetson Baseboard (with case)
Autopilot and Jetson on one board, enclosed. SKU 11072A.
RPi CM4 Baseboard
Autopilot and Raspberry Pi CM4 on one board. SKU 18080.
Pixhawk 6X
The compute module these baseboards take. SKU 11073.
Pixhawk Standard Baseboard V2B
Keep the companion computer separate. SKU 18125.
Holybro X650 ARF Kit
650 mm airframe and propulsion; avionics chosen separately.
Development drone kits
Airframes and kits to build a research platform on.
Sources & basis
What this is based on.
- Baseboard part numbers and the Pixhawk module family each one serves, and the development-kit range, as published in the Vebix Automation catalogue.
- Pixhawk telemetry ports are 3.3 V logic; confirm the level, pinout and flow-control support for your exact autopilot and baseboard in the manufacturer's documentation before wiring.
- The responsibility split, power arrangement and bench-test checklist are integration guidance drawn from how these builds fail. They are illustrative planning material, not a reported Vebix Automation field-test result, and no performance figure for any companion computer is claimed here.
- PX4 companion-computer connection (accessed 2026-09-07)
- PX4 1.16 Pixhawk Jetson baseboard setup (accessed 2026-09-07)
- Pixhawk Jetson baseboard overview and specification (accessed 2026-09-07)
- Pixhawk RPi CM4 baseboard overview (accessed 2026-09-07)
- Pixhawk RPi CM4 baseboard connections and ports (accessed 2026-09-07)
- Pixhawk Jetson baseboard dimension and weight (accessed 2026-09-07)
Published 7 September 2026. Last revised 7 September 2026. Corrections to sales@
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Planning a companion-computer build?
Send your controller model and required interfaces, the companion computer or the workload, peak current draw and the space available, and we will return a compatible component shortlist covering the baseboard, power and cabling. Request a component quotation, or ask about integration support in Pune.
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