This post used to carry the neat little “under fifty dollars” line. That was too tidy. Bare receiver boards can look cheap, but a useful GPS module plus antenna budget is now closer to $100 AUD, before cables, mounting, weather protection, or any steering hardware.

The useful promise is still the same: the software is free, the hardware is standard, and you can try a real guidance workflow without buying into a locked ecosystem.

What you need

  1. A Windows laptop - Windows 10 or later. An older cab laptop is fine if it is reliable and has a readable screen.

  2. A USB GPS receiver and antenna - Budget about $100 AUD for the module plus antenna. The right LC29H variant depends on the job: DA can suit lower-authority sensing, while BA is the current tractor guidance direction.

  3. A USB extension cable - Optional but usually useful. Keep it short and decent quality; flaky cables waste more time than they save.

  4. A mount - Roof or cab mounting with clear sky view. A receiver rattling around in the cab is not a guidance system.

  5. Power - Keep the laptop powered from the tractor. Bright screens and GPS receivers eat battery.

Step 1: Choose the GPS path

For public lightbar experimentation, use a simple USB receiver setup that Finn Guidance can see over a serial COM port. For tractor steering work, do not assume the cheapest receiver is the right receiver: the current FINN direction is an LC29H BA direct to the laptop.

FINN Base and RTK corrections are a later accuracy upgrade path, not a requirement for trying the basic lightbar.

Step 2: Download the software

Head to the Finn Guidance page and download the latest public release. It is a single .exe file, so there is no installer or setup wizard.

Step 3: Plug in and launch

  1. Plug the GPS receiver into your laptop’s USB port or extension cable.
  2. Mount the antenna with a clear view of the sky.
  3. Run finn-guidance.exe.
  4. Wait for the receiver to get a solid fix before trusting the display.

Step 4: Set your A-B line

  1. Drive to one end of your intended run and press Set A.
  2. Drive to the other end and press Set B.
  3. Your reference line is locked in and the lightbar can guide from there.

Step 5: Drive

The lightbar shows segments either side of centre. When the centre segment is lit, you are on line. Segments left or right show how far off-line you are and which direction to correct.

Each segment represents a configurable offset. Treat it as guidance, not magic: GNSS quality, antenna placement, terrain, and receiver choice all matter.

Saving your lines

Once you have set a good A-B line, save it from the field management screen. Next time you are in that paddock, load the line instead of setting it again.

You can also export lines as JSON files to move them between machines.

Tips from the paddock

  • Mount the antenna high and stable - Clear sky and repeatable placement matter.
  • Do not cheap out on the cable - USB dropouts look like software faults when you are busy.
  • Save lines often - Good A-B lines are worth keeping.
  • Use shade and brightness - Direct sun turns a poor screen into a guessing game.
  • Keep steering claims separate - Public lightbar use is not the same as a field-prototype auto-steer build.

What accuracy to expect

With standalone GNSS and no RTK correction service, expect metre-level guidance. That can be useful for broadacre guidance, spraying, spreading, and basic seeding work, but it is not controlled traffic precision and it is not a certified auto-steer product.

RTK support is part of the FINN Base direction. That should improve accuracy once the base station and rover paths are field-validated.

Need help?

Check the Guidance page and Hardware notes first. If something still does not make sense, email [email protected].