Introduction

HALPI2 is a pre-built, ready-to-use boat computer based on the Raspberry Pi Compute Module 5 (CM5). Powered by the same System-on-Chip (SoC) as the Raspberry Pi 5, it is fully compatible with all Raspberry Pi software as well as many hardware add-ons. Additionally, it offers a comprehensive set of features ideally suited for marine, automotive, and industrial applications.

HALPI2

Enclosure features include:

  • Waterproof (IP65) aluminium enclosure, size 200x130x60 mm
  • Standard connectors for power, NMEA 2000, gigabit ethernet, HDMI, and 2x USB 3.0
  • Connector options for 3x PG7 cable glands or SP13 waterproof connectors and 2x SMA connectors for external antennas

Hardware features include:

  • Power supply accepts voltages from 10 to 32 VDC and can withstand voltages up to 100 VDC without damage
  • Input current limited to 0.9 or 2.5 A (user-selectable)
  • Can be powered from a 12 V or 24 V battery or via NMEA 2000
  • Includes super-capacitors for short-term backup power - ideal for intermittent and "dirty" power sources
  • Detects power loss and can initiate a controlled shutdown
  • CM5 module in contact with the enclosure for passive cooling
  • Accepts standard M.2 NVMe SSD disks for fast storage
  • Standard Raspberry Pi 40-pin GPIO header for additional hardware add-ons
  • Carrier board includes 2x HDMI, 2x MIPI (DSI/CSI), 4x USB 3.0, gigabit ethernet, CAN-FD (NMEA 2000) and RS-485 (NMEA 0183) interfaces, and a real-time clock backup battery
  • Five RGB LEDs for status indication
  • User-configurable button headers for custom functions

Software features include:

  • Carrier board controller communicates with the CM5 via I2C
  • Host daemon software can monitor voltage levels, current consumption, and temperatures of the CM5 and carrier board
  • Supports transparent firmware updates over I2C
  • Usable without the daemon software, with reduced functionality

This user guide provides information on how to set up and use HALPI2 as well as information on the hardware and software features.

Quick Start Guide

Hardware Setup

Powering

HALPI2 can be powered either using the dedicated E7T power connector (compatible with Amphenol LTW Ceres Mini) and the provided power cable, or via NMEA 2000. The power supply should provide a voltage between 11 and 32 VDC.

Powering via E7T Connector

By default, the power input is via the E7T connector. Connect the provided power cable to the boat electrical system, ensuring the correct polarity. The power cable needs to be fused with a fuse rated for 3 or 5 A, either with an inline fuse or in the electrical panel.

Powering via NMEA 2000

If you want to power the HALPI2 via NMEA 2000, open the enclosure and connect the green terminal connector on the NMEA 2000 wiring harness to the carrier board power connector, replacing the existing terminal block. The NMEA 2000 drop cable should be close to the power feed cable to avoid excessive voltage drop on the NMEA 2000 trunk.

Input Current Limiting

The default input current limit is set to 0.9 A, which is suitable for most applications. If you need to increase the limit to supply more power to peripherals or to speed up the initial charging of the super-capacitors, you can change the Input Current Limit toggle switch on the carrier board to the 2.5 A position.

When using NMEA 2000, the input current limit must be set to 0.9 A, as NMEA 2000 devices are not allowed to draw more than 1 A from the bus.

Mounting

HALPI2 can be wall-mounted using 4 mm screws or M4 bolts. The screw holes can be found under the enclosure lid. If possible, mount the computer with the connectors facing downwards to reduce the risk of water ingress.

Connecting Peripherals

Connecting peripherals is straightforward. Use the appropriate connectors and cables to link your devices to the HALPI2.

If you need to modify the connector configuration, remove the existing panel connectors using a socket wrench socket without the ratchet arm - finger tightening is sufficient for the plastic threads! The large connectors take a 26 mm socket. The bottom row blind plugs can be removed with a large flat head screwdriver. The SMA connector nylon bolts can be removed with a 10 mm socket. When installing new SMA connectors, the brass nut can be finger-tightened using an 8 mm socket. Use only waterproof SMA connectors that have a wide flange on the inside of the enclosure to ensure a good seal.

Software Setup

Hat Labs provides pre-built images for HALPI2, which can be downloaded from GitHub. The pre-built images include the necessary configuration and customizations for the HALPI2 hardware.

All pre-built images have the CAN (NMEA 2000) interface enabled by default, as network device can0. RS-485 (NMEA 0183) is available as /dev/ttyAMA0.

OpenPlotter

OpenPlotter is a Raspberry Pi OS operating system image with useful additions for marine applications. The pre-installed image is based on the OpenPlotter Headless edition that enables a WiFi Access Point for easy configuration and access to the HALPI2.

If you are not using a display, keyboard and a mouse with the HALPI2, you can connect to the computer either using an Ethernet cable or via the WiFi Access Point.

With either, you can access the HALPI2 computer using VNC or SSH. VNC provides a remote desktop interface to access the HALPI2 desktop, while SSH allows you to access the command line interface. You need to download RealVNC's VNC Viewer to use VNC.

Since both the access point and the default user come with default passwords, it is imperative that the passwords are changed immediately after the first boot. The process is described in the OpenPlotter documentation.

Raspberry Pi OS and Raspberry Pi OS Lite

If you prefer to use the standard Raspberry Pi OS, you can download the latest image with HALPI2 support from the GitHub repository. Flash the image to the SSD disk using Raspberry Pi Imager. When flashing, you can apply customizations such as setting the hostname, enabling SSH, and configuring WiFi.

If you decide to not apply customizations, you need to have a display and keyboard connected to the HALPI2 to complete the initial setup. You will be asked to provide a username and password at the first boot.