01
Apr
Why I built my own GPS guidance system
I’ve been farming with my father in Jamestown, South Australia for years. Mixed operation — cropping and livestock. Like every broadacre farmer, …
guidanceOpen Source Farm Tech
GPS guidance for any laptop, under $50
Finn Guidance turns your laptop and a USB GPS module into a working lightbar. No proprietary hardware. No subscriptions. No dealer required. Built by a farmer, for farmers.
Up and running in three steps
From box to paddock in under five minutes.
1
Plug in the GPS
Connect the USB GPS module to your laptop. Finn Guidance auto-detects the COM port — no drivers, no fiddling.
2
Set your A-B line
Drive to your start point, mark A. Drive to the end, mark B. That's your reference line set.
3
Follow the lightbar
The on-screen lightbar shows your cross-track error in real time. Stay centred and keep your passes straight.
Built for real farm work
Not a tech demo. Every feature exists because a farmer needed it.
📡
Plug & Play GPS
Works with the LC29H DA module — a $30 USB GPS receiver. Auto-detects COM ports so you just plug in and go.
💡
Visual Lightbar
Clear, intuitive cross-track error display. Configurable segment width to match your accuracy needs.
🗂️
Field Management
Save and load A-B lines grouped by field. Transfer lines between machines with JSON export/import.
🔄
Auto-Pass Selection
Automatically selects the nearest pass based on your implement width and overlap settings.
🌱
Nudge for Inter-Row
Offset your guidance line by a precise amount for inter-row sowing. Perfect for controlled traffic and relay cropping.
📊
Coverage Logging
Records where you've been with SQLite storage and CSV export. See your coverage and never miss a strip.