Sanctuary Systems' Sentinel Core Turns a Raspberry Pi Compute Module 5 Into a "Better Computer"

Sanctuary Systems is looking to launch an open source carrier board for the Raspberry Pi Compute Module 5, built with easy experimentation in mind — and featuring a full-size PCI Express slot in a mini-ITX footprint: the Sentinel Core.

"Where most Compute Module [carrier] boards aim to be a better Raspberry Pi, Sentinel Core aims to be a better computer," Sanctuary Systems' Pepijn de Vos and Pepijn Goorden explain. "It packs the [Raspberry Pi] CM5 in a standard mini-ITX motherboard with all the usual connectors and a full sized PCIe slot ready for any expansion card you can think of. Whether you want to run local LLM [Large Language Model]-powered voice assistants, Jellyfin or Plex video transcoding, or something yet to be dreamed up, Sentinel Core gives you the freedom to take the Raspberry Pi CM5 to the next level."

The board, designed for use with any mini-ITX chassis, features two board-to-board connectors for the Raspberry Pi Compute Module 5, a computer-on-module built around the same Broadcom BCM2712 system-on-chip as the Raspberry Pi 5 single-board computer. The rear of the carrier board brings out a single gigabit Ethernet port, one USB 2.0 Type-C and two USB 3.0 Type-A ports, and two full-size HDMI ports, while elsewhere on the board is a 40-pin general-purpose input/output (GPIO) header plus a 24-pin ATX connector for a PC-style power supply.

The board's biggest selling point, though: a full-size PCI Express slot, capable of accepting add-in boards up to x16 mechanical — though it's wired into the Raspberry Pi Computer Module 5 with a single PCI Express lane, so you won't get full performance from something like a high-end graphics card, multi-gigabit network card, or many-core accelerator for machine learning or artificial intelligence workloads.

"Sentinel Core is an open-hardware project," de Vos and Goorden say. "We believe a system you rely on should never be a black box, which is why all major design resources will be made available, likely under the [permissive] CERN-OHL-P license. This includes the hardware schematics, board layout files, the full bill of materials, 3D-printable accessories, and supporting scripts/utilities used for setup and testing. We will also share example configurations for Home Assistant, helping users get started quickly without locking them into any specific software stack."

The Sentinel Core is heading to crowdfunding soon, with interested parties invited to sign up on Crowd Supply to be notified when the campaign goes live; some project files have already been uploaded to GitHub under an unspecified license. Additional information is available on the Sanctuary Systems website.