Specifications
Sixfab Edge AI Expansion Board specifications
Electrical, mechanical, thermal, and software specifications for the Sixfab Edge AI Expansion Board for Raspberry Pi 5. Use it as the canonical reference when sizing power supplies, selecting M.2 modules, or designing custom enclosures around the under-board stack. Intelligented by DEEPX. Built on Raspberry Pi.
Quick reference
Headline figures at a glance. Scan this block first; full per-category detail follows below.
Technical specifications
Per-category breakdown of the Edge AI Expansion Board electrical, mechanical, and software specifications.
dxrt-runtime
dtparam=pciex1_gen=3
/dev/sda)
sixfab-dx
dxrt-runtime
dxrt-cli · dxtop
Connectors & slots
Five user-facing interfaces on the board: three M.2 slots, the PCIe FFC link to the Pi 5, and the USB-C PD power input. Plus a pogo-pin back-power array on the top surface, a nano SIM slot, and a USB-A passthrough for the internal USB Bridge.
Single power input for the entire stack. The board back-powers the Raspberry Pi 5 through pogo pins; the Pi 5's own USB-C port stays unused. Below 27 W the system shows a visible under-voltage warning and throttles.
RPI5 / EDGE_AI
Dedicated PCIe link between the Raspberry Pi 5 and the DEEPX DX-M1 in the M.2-PCIE slot. The RPI5-labelled end goes to the Pi 5's PCIe FPC port; the EDGE_AI-labelled end goes to the Expansion Board's FFC connector. Labels face outward, metal pins inward.
The only slot wired to the dedicated PCIe link. Houses the DEEPX DX-M1 M.2 module. The included spacer sits between the module and the Expansion Board's mounting hole. Insert at 30° and finger-tighten the M2 screw.
/dev/sda
NVMe SSD slot routed through the on-board USB 3.0 hub and a Realtek USB-to-NVMe bridge. The OS sees a USB Mass Storage device, not a native NVMe block device. M.2 SATA modules are not supported.
M.2 Key-B slot for an LTE or 5G modem module, exposed to the OS over the internal USB 3.2 Gen 1 hub through the USB Bridge. The board carries no built-in antennas; the antenna connector type depends on the chosen modem module.
Four spring-loaded contacts on the top surface that press into 5V and GND pads on the underside of the Raspberry Pi 5 GPIO header. No data signals are routed through pogo pins; they carry power only. Spacer torque is critical for reliable contact.
Short USB-A bridge that connects the on-board hub to one of the Raspberry Pi 5's blue USB 3.0 ports. Mandatory for both the NVMe SSD and the LTE/5G modem to function. The Pi 5's remaining three USB ports (one USB 3.0, two USB 2.0) stay free for peripherals.
Hardware developers integrating the Expansion Board into custom carrier designs work from the user-facing interfaces above only. There are no exposed debug UART, GPIO pass-through control, or user-configurable hardware bridges. The GPIO header on the Pi 5 is forwarded upward unchanged, so a standard top-mounted HAT can co-exist. See Pinout & GPIO.
LED indicators
The Expansion Board has four LEDs grouped near the edge of the PCB. One is for power; the other three are wired to the module slots (cellular network activity, NVMe SSD activity, and the M.2 connector on the PCIe line). The LEDs are hardware-driven and cannot be controlled programmatically. Detailed runtime telemetry lives in dxrt-cli and dxtop, see System Monitoring.
On when the Expansion Board is receiving valid USB-C PD input and its on-board rails are up. Off indicates no power, an under-voltage PSU, or a USB-C cable issue.
Driven by the LTE/5G modem in the CELLULAR slot. Indicates network registration and signal activity. Specific blink-vs-solid meaning is set by the modem module's firmware, refer to the installed module's datasheet for the exact decoding.
Direct activity LED for the NVMe SSD in the M.2-SSD slot. It blinks during read, write, and erase operations on the installed SSD, and stays off when no SSD is present. It does not indicate internal USB hub or cellular traffic.
Controlled through the M.2 connector on the PCIe line. The DEEPX DX-M1 does not currently drive this LED output, so with the DX-M1 installed the LED shows no activity; an NVMe SSD installed in this slot would drive it. Activity indication for the DX-M1 is in progress.
Cooling
Each part of the assembled stack has its own cooling path. Plan cooling per component, and validate the result at the target ambient temperature before deployment.
The official Raspberry Pi Active Cooler is recommended for the Raspberry Pi 5. It matters for AI workloads: it keeps the Pi 5 running without thermal throttling while it drives the inference pipeline.
Always install the heatsink supplied with the DEEPX DX-M1 module. If your workload or enclosure calls for active cooling on the module, contact Sixfab.
If these modules need cooling in your deployment, commercially available passive or active coolers in a suitable form factor can be used. Contact Sixfab for detailed guidance.
If the setup will run in a hot environment or inside a closed enclosure, make sure system-level cooling is part of the design from the start, and verify thermal headroom before shipping.
The DX-M1 reduces clock rate when on-NPU temperature approaches roughly 90 °C. Live temperature is exposed by dxrt-cli -s and the running view in dxtop. Continuous throttling indicates insufficient cooling for the workload, so either reduce duty cycle, add active cooling, or improve enclosure airflow.
Mechanical dimensions
Under-board baseboard for Raspberry Pi 5, mounted underneath via M2.5 spacers. Off-the-shelf Pi 5 cases generally do not fit the assembled stack, so custom enclosures are expected for deployment. See Quickstart for the full assembly sequence.
Compliance
Regulatory and safety certification status for the Edge AI Expansion Board. Status reflects what has been confirmed by Sixfab R&D as of this revision.
Safety & handling
Handle the board by its edges and avoid touching the onboard components, connector contacts, and header pins with bare hands. Observe normal anti-static precautions when unpacking and installing.
Always power off the Raspberry Pi 5 completely and disconnect the USB-C PD cable before installing, removing, or swapping M.2 modules, the PCIe FFC cable, or the USB Bridge. Hot insertion or removal can damage the DEEPX DX-M1, the NVMe SSD, the modem module, or the Pi 5 itself through current spikes on the PCIe and USB rails.
The minimum supported PSU is the Raspberry Pi 27 W USB-C PD Supply. The 45 W supply is recommended whenever the AI accelerator, NVMe SSD, and LTE/5G modem are populated together. Standard 5 V / 3 A (15 W) phone chargers will trigger under-voltage warnings and may reboot the system. If you boot from the NVMe SSD, also set usb_max_current_enable=1 in /boot/firmware/config.txt on first boot; without it, the Pi 5 pauses at boot and waits for a button press. This setting is not required when running from a microSD card.
The 15 mm and 5 mm M2.5 spacers, the 4× M2.5 mounting screws, and the 3× M2 6 mm flat-head M.2 screws are all finger-tight only. Loose spacers cause intermittent pogo-pin contact, which surfaces as power glitches or reboots under inference load. Over-torquing strips the threads in the spacers and the threads are not field-repairable. No power driver.
Physical design notes
- No buttons or switches on the Expansion Board. No reset, no power button, no user-programmable switch. Power state follows the USB-C PD input.
- No back-feed protection on the Pi 5 USB-C side. Power must come from the Expansion Board only. Plugging a second PSU into the Pi 5's USB-C port causes only the Pi 5 itself to operate, and the Expansion Board stack is unsupported in that configuration.
- No power-monitoring circuitry. Real-time per-slot or full-stack power draw is not measurable from the Raspberry Pi side.
dxtopexposes NPU-side power only; full-stack power requires an external USB-C power meter. - No vibration qualification. The pogo-pin back-power connection has not been qualified for high-vibration environments (drones, mobile robots). Long-term reliability under sustained shock and vibration is unverified.
- Indoor commercial use. The Edge AI Expansion Board is a commercial-grade electronic assembly intended for indoor deployment. Outdoor use requires a sealed enclosure addressing moisture, temperature, ventilation, and airborne contaminants.
Updated 20 days ago