OreSat GPS Software

OreSat GPS software runs the OreSat GPS card and publishes navigation data to the satellite over CANopen. It is designed to hide receiver-specific details and provide a consistent interface for the rest of the flight software.

This app targets custom OreSat GPS hardware (oresat-gps-hardware) and supports two reception paths on the card:

• SkyTraq Orion B16 (current operational path)
• MAX2771 SDR path (hardware present; software path not yet implemented in this repo)

The CANopen-facing interface provides GPS-derived data such as position, velocity, fix quality, satellites-in-view, and time fields used by other systems. During development, you can inspect CAN traffic with tools like candump and interact with objects through standard CANopen tooling.

GPS is also used as a high-quality time reference. When a valid fix is available, the app can synchronize system time so other spacecraft services share a common clock base for telemetry correlation, event ordering, and time-sensitive control loops.

In the wider satellite stack, this data is consumed by components like ADCS and mission operations pipelines for state estimation, timeline reconstruction, and post-pass analysis.

Like other OreSat apps, this project is built on OLAF. When running locally, OLAF's debug interface is available at http://localhost:8000, including a GPS page at http://localhost:8000/skytraq.

Quick Start

Install dependencies.

pip3 install . --group dev

Make a virtual CAN bus.

sudo ip link add dev vcan0 type vcan
sudo ip link set vcan0 up

Run the GPS app.

python3 -m oresat_gps

Select the CAN bus to use (vcan0, can0, etc) with the -b BUS arg.

Mock hardware by using the -m HARDWARE flag.

• The -m all flag can be used to mock all hardware (CAN bus is always required).
• The -m skytraq flag would only mock the skytraq

See other options with -h flag.

A basic Flask-based website for development and integration can be found at http://localhost:8000 when the software is running.

Architecture Notes

Low-level receiver protocol details are intentionally abstracted behind the app interface, but for maintainers:

• The SkyTraq path is implemented in a userspace driver at oresat_gps/skytraq.py.
• Host-to-SkyTraq commands use the SkyTraq binary protocol (see AN0037).
• SkyTraq navigation reports are parsed and mapped into CANopen object dictionary entries.