OpenCPN and d3kOS — how they work together

OpenCPN is a free, open-source chart plotter application that can run on the same Raspberry Pi as d3kOS. Understanding how the two systems interact helps you get the best from both.

What OpenCPN does. OpenCPN is a full chart navigation application — it displays vector and raster charts, plots your position, tracks your route, and shows AIS traffic. It reads NMEA data from Signal K (which d3kOS uses as its data broker) so it has access to all the same GPS, depth, wind, and engine data that d3kOS displays.

What d3kOS adds that OpenCPN does not have. d3kOS provides the AI voice assistant, predictive engine maintenance, natural language queries, and the mobile companion app. OpenCPN provides the chart display. They complement each other rather than compete.

Running both on the same Pi. The Raspberry Pi 5 (8 GB) has sufficient resources to run d3kOS and OpenCPN simultaneously, though CPU usage will be higher. The recommended configuration is to run OpenCPN on a dedicated display (connected to the Pi’s HDMI output) while d3kOS is accessed from a phone or tablet over Wi-Fi.

Charts for OpenCPN. OpenCPN uses vector charts from the o-charts service for most of the world outside the USA. o-charts requires a paid licence per chart region. Encrypted CM93 charts are an alternative. Free NOAA raster charts are available for US waters.