OpenPinMarker
Clip it to the flagstick, press the button, and today's pin is measured. A small open box that any club can build for about a hundred euros. A concept from October 2026.
The idea
The flag already stands in the middle of the cup. The marker rides along.
A pin typed in as metres from the front and the side is an estimate, as good as the map of the green. A measured pin carries its own accuracy. Phones can't get there: their antenna sits inside the case, between battery and hand, and stays at metre level. A receiver with its own antenna and correction data gets to centimetres.
At the green
- Cut the hole and set the flag.As always.
- Clip the marker on, about a metre up.The flagstick centres it over the cup. At that height a lean of five degrees costs nine centimetres.
- Press the button and wait a few seconds.One buzz on the phone: saved. Three: once more.
- Take it off and walk on.The phone keeps count of the holes done and still to do. Back at the shed, the pins go out.
What's inside
| Part | Price, October 2026 |
|---|---|
| Receiver. Multi-band GNSS board, Quectel LG290P class (L1, L2, L5, E6) | from 57 € |
| Antenna. Helical, on top of the box | from 17 € |
| Controller. ESP32-C3, joins the phone's hotspot | about 5 € |
| Power. One 18650 cell, charged over USB-C | about 7 € |
| Case and clamp. Printed; the clamp fits poles of 12 to 25 mm | about 3 € |
| Marker | about 90 to 125 € |
Order the parts, print the case, solder a few wires, and install the firmware over USB from a web page. One button, one light; the phone has the screen.
Corrections
Centimetres need correction data, and every club has different ones within reach. The marker takes them all through NTRIP, the standard protocol.
- Your own base on the clubhouse roof, about 150 to 300 € once. Centimetres anywhere in the world.
- A service the club already uses, national or commercial.
- Free corrections from Galileo's High Accuracy Service or precise orbits over the internet. They take 15 to 20 minutes to settle, so the marker stays on for the round.
Every measurement also keeps its raw satellite data. A green without signal is corrected later on the server.
How close
| Corrections | Expected |
|---|---|
| Own base or service, open sky | 1 to 2 cm |
| Own base or service, harder spots | around 13 cm |
| Free corrections, after settling | 12 to 20 cm |
These come from published tests with the same receiver class. The 2027 pilot checks them on real greens, against surveyed points. A pin sheet counts in whole yards.
Open
Circuit, firmware, case and the pilot results go into a public repository under open licences. Want to be the club that tries it first? Write to us.