FAQ

Frequently asked questions about the Interceptor Carrier Board

6 minute read

Compute Module Compatibility

Can I use a Raspberry Pi CM5?

Yes, with limitations. The Raspberry Pi CM5 is compatible with the Interceptor Carrier Board, but USB boot is not supported.

Why: The Interceptor Carrier Board uses USB 2.0 ports. The CM5 only enables boot capability on USB 3.0 ports.

Solutions:

SD Card Boot: If your CM5 has a blank eMMC (never written to), it will automatically try to boot from the SD card slot
eMMC Boot: If your CM5’s eMMC has been initialized, you must flash the OS to the eMMC using:
- A separate Raspberry Pi CM5 IO Board
- The rpiboot utility to expose the eMMC as a mass storage device
- Your favorite imaging tool (Raspberry Pi Imager, dd, etc.)

Important

You cannot flash a CM5 with eMMC directly on the Interceptor board. The USB boot path is incompatible. You must remove the CM5, place it on a Raspberry Pi IO board, flash it there, then reinstall on the Interceptor.

Can I use a Raspberry Pi CM4?

Yes, fully supported! The CM4 works well with the Interceptor Carrier Board.

Boot options:

eMMC variants: Flash via USB boot using rpiboot
Lite variants (no eMMC): Boot from SD card or USB drive
USB boot: Supported for installation

Can I use a Banana Pi CM4?

Yes, with limitations. The Banana Pi CM4 is compatible, but with these restrictions:

Feature	Status
HDMI0 (J4)	✅ Works
HDMI1 (J5)	❌ Not supported
Power button (J2)	❌ Not functional
SD Card boot	✅ Works
SATA	✅ Works
Ethernet	✅ Works

Workaround for HDMI: Connect your monitor to J4 (HDMI0). If you need dual displays, consider using the Raspberry Pi CM4/CM5 instead.

What CM4/CM5 variants work best?

Any variant works, but consider:

With eMMC: Faster, more reliable than SD card
With WiFi: Useful for initial setup, but wired Ethernet is recommended for production use
CM5: Better performance, but requires eMMC or SD card boot (no USB boot)

Storage & Boot Options

Does the board have an SD Card slot?

Yes. The Interceptor Carrier Board (v2.0) features a Micro SD Card slot (labeled U18).

SD Card boot compatibility:

✅ Raspberry Pi CM4 Lite (no eMMC)
✅ Raspberry Pi CM5 with blank eMMC
✅ All Banana Pi CM4 variants
❌ CM5 with initialized eMMC (cannot force SD boot)

Version Note

SD Card support requires Interceptor Carrier Board v2.0.

Can I boot from a USB drive?

Module	USB Boot	Notes
CM4	✅ Yes	Generally supported for installation
CM5	❌ No	Interceptor uses USB 2.0; CM5 only boots from USB 3.0
Banana Pi	✅ Yes	Check specific variant documentation

Does the board support boot from SATA?

Not directly. The Raspberry Pi firmware does not support booting directly from SATA.

Workaround: You can configure a hybrid boot setup:

Keep the /boot partition on eMMC or SD card
Mount the root filesystem (/) from a SATA drive
Edit cmdline.txt to point to the SATA partition:
```
root=/dev/sda1 rootfstype=ext4 ...
```

For “Lite” Compute Modules (without eMMC), a USB flash drive or SD card must remain connected to hold the boot files.

What RAID levels are supported?

The JMB585 SATA controller supports software RAID via mdadm:

RAID 0 (striping)
RAID 1 (mirroring)
RAID 5 (striping with parity)
RAID 6 (striping with dual parity)
RAID 10 (mirrored stripes)

Hardware RAID is not supported; all RAID is handled in software.

How many drives can I connect?

5 SATA drives maximum (connectors J11-J15).

PoE

How do I power the PoE boards?

You cannot power the PoE boards solely through the motherboard traces. You must install the VOITA 48Vdc Power Converter.

Wiring:

Connect VOITA input to the CPU 4+4 pin connector of your ATX power supply (12V)
Connect VOITA output to the green terminal block on the first PoE board

Required

The VOITA 48V converter is required for PoE functionality. Without it, the PoE ports will not deliver power.

How do I control PoE power?

The ip link set poeX up/down command only controls the data link, not the actual power output.

To control power (turn ports on/off), use the /proc/pse interface:

# Disable port 3 on board 0
echo "disable-port 0 3" > /proc/pse

# Enable port 3 on board 0
echo "enable-port 0 3" > /proc/pse

# Check status of all ports
cat /proc/pse

Requirement: OS image dated 2025-05-01 or newer (2025-04-30 for Banana Pi).

How do I change PoE mode (802.3af vs 802.3at)?

By default, ports are configured for 802.3at (PoE+, 30W). To limit a port to 802.3af (15W), use:

echo "set-af-mode <board> <port>" > /proc/pse

Example:

# Set port 2 on board 0 to AF mode (15W max)
echo "set-af-mode 0 2" > /proc/pse

How many PoE ports can I have?

Single PoE board: 8 ports (via J9)
Dual PoE boards: 16 ports (via J9 and J10)

What PoE standard is supported?

802.3at (PoE+): Up to 30W per port (default)
802.3af (PoE): Up to 15W per port (configurable)

Cooling

Can I control fan speed?

No. The four fan headers (M1-M4) are standard 3-pin 12V connectors. They do not support PWM speed control. Connected fans will run at full speed.

Alternatives:

Use quiet/low-noise fans
Use an external PWM fan controller
Use a fan with built-in thermal control

Software & OS

What OS should I use?

We recommend the official exaviz OS images, which include all necessary drivers. Available at exaviz.com/downloads.

Module	OS Version Required
Raspberry Pi CM4/CM5	2025-05-01 or newer
Banana Pi CM4	2025-04-30 or newer

The OS is based on Debian 12 “Bookworm” (or Debian 11 “Bullseye” for older versions).

Other options:

Raspberry Pi OS (may require manual driver installation)
Ubuntu Server (may require manual driver installation)

Can I use Windows?

Windows IoT is not supported. The Interceptor is designed for Linux only (specifically Debian/Raspbian-based distributions).

However, you can use a Windows PC to flash OS images:

Recommended tools:

Raspberry Pi Imager
Balena Etcher

Known Windows issues: Some users report problems when flashing exaviz OS images directly to the board via USB boot on Windows, receiving errors like “GPT no bootable partition” (while standard Raspberry Pi OS images work fine).

Workarounds:

Try flashing from Linux or macOS instead
Flash the storage media (SD card/SSD) externally using a USB adapter
Use a different flashing tool

How do I access the serial console?

Connect a 3.3V USB-to-Serial adapter to J2:
- Adapter TX → J2 Pin 6 (RX)
- Adapter RX → J2 Pin 5 (TX)
- Adapter GND → J2 Pin 7 or 8
Use serial terminal settings: 115200 8N1
Power on the board

Warning

Do not use a 5V USB-to-Serial adapter! This will damage the compute module.

Power

What PSU do I need?

Any standard ATX PSU with a 24-pin (or 20-pin) connector. Key requirements:

Stable +3.3V rail (critical!)
Minimum 300W for basic configuration
500W+ if using PoE boards
Quality brand recommended (Corsair, EVGA, Seasonic)

Why does my system crash randomly?

Most likely cause: Unstable +3.3V rail from PSU.

Low-quality or older PSUs often cannot maintain proper 3.3V voltage under the low-load conditions typical of Raspberry Pi systems. Solution: Use a quality modern PSU.

Identification

Where can I find the serial number or MAC address?

Serial number stickers: Located on the underside of the carrier board or on the packaging box
MAC addresses: Software-assigned and managed by the OS. Check with:
```
ip link show
```
or
```
cat /sys/class/net/eth0/address
```

FAQ