ARK Jetson PAB V3 Modalix Bundle

ARK Jetson PAB Carrier V3, SiMa.ai Modalix SOM, heatsink and fan. Optional NDAA 480GB M.2 NVMe SSD.

The carrier is the same hardware as ARK Jetson PAB Carrier V3 — ARKV6X flight controller, Pixhawk Autopilot Bus, I/O co-processor, avionics connectors, and Payload Bus. This page covers SOM differences only.

The ARK carrier is NDAA. The SOM is SiMa.ai.

Carrier Hardware

ARK Jetson PAB Carrier V3

Use the PAB V3 Hardware Reference for pinout, power, and 3D models. Do not use the PAB V3 Flashing Guide or USB-C Console gadget login.

Where to Start

Do not use NVIDIA SDK Manager or L4T. The SOM boots from built-in eMMC; an NVMe SSD is not required.

1. Apply the ARK carrier overlay to the running eLxr image — ark-meta-simaai. The overlay ships as a versioned release package:

   curl -LO https://raw.githubusercontent.com/ARK-Electronics/ark-meta-simaai/main/packaging/provision_from_package.sh
   chmod +x provision_from_package.sh
   BOARD=sima@<ip> ./provision_from_package.sh pab-v3

   cat /etc/ark_modalix afterwards reports which overlay release the board carries.

2. Install the ARK-OS modalix package — see ARK-OS.

3. ML tooling — SiMa.ai Palette and SiMa.ai hardware docs.

SiMa eLxr default login: user sima, password edgeai, hostname modalix. ARK-OS services run as sima.

Interface Differences

Interface	Modalix
UART2	Works as a console (UART2 debug header)
CAN	No SOM CAN. Flight-controller CAN on the avionics connectors is unchanged.
HDMI	Works only if the Modalix SOM was ordered with the HDMI option. ARK units will not have HDMI. The V3 Micro HDMI connector is unused.
PCIE2	Only works when HDMI is not used. On ARK units (no HDMI), PCIE2 is available
M.2 Key E	No PCIE
USB-C	USB 3.0 works as a host. USB 2.0 on that connector goes to an FTDI console on the SOM (not Jetson gadget device mode)
UART0	Works without flow control (no RTS/CTS)
UART1	Does not work. On this carrier UART1 is the SOM-to-flight-controller serial (Telem2).
Ethernet	Links at 100 Mb/s, not gigabit. The KSZ8795 switch is held in reset on stock eLxr, so there is no Ethernet at all until the ARK overlay is applied.

Do not install the Jetson Wi-Fi 6E / Remote ID M.2 option — M.2 Key E has no PCIE on Modalix.

The PAB V3 Autopilot Connections UART map (/dev/ttyTHS1 → Telem2) is for NVIDIA Jetson modules.

Flight Controller

USB and Ethernet between the Modalix SOM and the ARKV6X are functional. UART1 / Telem2 is not.

Use USB or Ethernet for MAVLink (and for DDS, if you need it). Do not use the Jetson serial path.

Flight-controller CAN, PWM, GPS, and the rest of the avionics connectors are on the ARKV6X and are unchanged.

Console

UART2 is the console. USB-C USB 2.0 is an FTDI console on the SOM. USB-C USB 3.0 is host only.

On a freshly flashed eLxr image the SOM USB-C console is the only way in: the KSZ8795 switch is held in reset until the ARK overlay releases SWITCH_RSTn, so Ethernet does not come up. Apply the overlay over that console, reboot, and Ethernet works on its own from then on.

Do not use the Jetson USB-C gadget login (jetson / 192.168.55.1). The SOM has no USB device controller at all (/sys/class/udc is empty), so no USB gadget networking of any kind is available — this is not just a different gadget address.

Recovery

If the eMMC image is unbootable, reflash eLxr with SiMa's netboot path — scripts/netboot-elxr-pab-v3.sh in ark-meta-simaai, which drives sima-cli over TFTP. There is no NVIDIA Force Recovery mode on this SOM.

Storage

Boots from on-module eMMC. M.2 Key M NVMe is optional extra storage.

Display / PCIe

ARK-sold Modalix SOMs do not include HDMI. The V3 Micro HDMI connector is unused. Because HDMI is unused, PCIE2 is available.

M.2 Key M is still NVMe. M.2 Key E has no PCIE.

ARK-OS

ARK-OS is a Debian package, not a full OS image. Flash eLxr first, then install the modalix platform on the board (user sima must exist):

curl -fSLO https://github.com/ARK-Electronics/ARK-OS/releases/download/v1.3.0/ark-os-modalix-bookworm_1.3.0_arm64.deb
sudo apt-get install -y ./ark-os-modalix-bookworm_1.3.0_arm64.deb

Use apt-get install, not dpkg -i — the package has dependencies (nginx, gstreamer) that only apt resolves.

The package is named bookworm while eLxr 12 reports its own codename, aria. They are ABI-compatible; the bookworm build is the one to install. If you use packaging/install_ark_os.sh instead, pass --codename=bookworm, or it will look for an aria asset that is not published.

Do not install the jetson package.

ARK-UI is at http://modalix.local (or the board's IP). Do not use jetson.local or USB-C gadget networking.

Compared with ARK-OS on Jetson:

• No jtop / jetson-stats

• No jetson-can (no SOM CAN)

• No rid-transmitter

• FMU reset / VBUS GPIO helpers are no-ops until mapped

• mavlink-router can use the USB flight-controller path

• Do not use XRCE-DDS on UART1 / Telem2 — that serial link does not work

ARK-OS

Performance

Vendor peak ratings, not a lab benchmark:

Module	Peak TOPS	Rated power
SiMa.ai Modalix	50 TOPS (BF16/INT8/INT16)	sub-10W
NVIDIA Jetson Orin Nano 8GB	40 TOPS; Super 67 TOPS	25W
NVIDIA Jetson Orin NX 16GB	100 TOPS; Super 157 TOPS	40W

Modalix has higher TOPS per watt than Orin Nano Super and Orin NX Super at those rated points. Peak TOPS on Super NX is higher.

External

• SiMa.ai MLSoC Family

• SiMa.ai Developer Center (Palette)

• SiMa.ai Hardware Docs

• ark-meta-simaai — ARK carrier device tree and flash tooling

• ARK-OS — modalix platform package