DIY and Open-Source Launch Monitors: What Actually Works
By Patrick Kavanagh ·
The honest answer up front: yes, you can build a working golf launch monitor from off-the-shelf parts today, and two open-source projects — PiTrac and OpenFlight — have real, active communities doing exactly that. But “working” comes with caveats both projects state themselves, the parts bill lands between roughly $250 and $534 before your time, and a finished $199.99 pocket radar beats a DIY rig on reliability per dollar if all you need is speed and distance. Where DIY genuinely wins is capability: a completed PiTrac measures spin — something no commercial unit under $500 does.
This post covers what the open-source scene actually offers in late 2026, what the builds cost against current retail prices, and which path fits which golfer.
The two projects that matter: PiTrac and OpenFlight
The open-source launch monitor scene has consolidated around two serious projects that take opposite technical approaches — the same camera-versus-radar split you see in commercial launch monitors.
PiTrac is the camera-based option. Per its GitHub repository (now under the PiTracLM organization, GPL-2.0 licensed), it uses high-speed infrared strobe-based image capture with Raspberry Pi hardware and low-cost Pi Global Shutter cameras to determine ball speed, launch angles, and spin in three axes. That spin measurement is the headline: photometric spin is what separates premium camera units from budget radar, and PiTrac does it with roughly $50 cameras. It interfaces with GSPro and E6/TruGolf, and shot data is viewable in a standalone web app. The project began as James Pilgrim’s build, gained attention through its Hackaday project page, and remains active as of mid-2026 with around 400 GitHub stars and a dedicated documentation site at docs.pitrac.org.
OpenFlight is the radar-based option, started by software engineer Coleman Rollins. Per its GitHub README (AGPL-3.0 licensed, roughly 1,200 stars), it pairs an OmniPresense OPS243-A Doppler radar with a Raspberry Pi 5 and a touchscreen, measuring ball speed at a claimed ±0.5% accuracy, club speed, and smash factor. Launch angle requires an optional TI IWR6843 angle radar; without it, launch is estimated. Spin and club path are explicitly labeled experimental, and spin is not used for carry calculations by default. It streams shots to GSPro and other simulator software through connectors.
Both projects are candid about maturity. PiTrac’s documentation describes a young project where “the basic features usually work reliably, but the current release needs polish.” OpenFlight’s README warns that features “may be incomplete, unstable, or change without notice.” Neither is a kit you assemble in an afternoon — PiTrac’s docs say builders need soldering skills, 3D printing access, and comfort compiling software on Linux.
What a build really costs in 2026
Here is the buy-versus-build math using each project’s own published parts figures against the retail prices we track.
| Option | Approach | Documented cost | Spin? | Sim support |
|---|---|---|---|---|
| PiTrac (DIY) | IR strobe cameras | ~$250+ in parts per its docs (Pi 5 8GB ~$134.50, two Global Shutter cameras ~$50 each, custom PCB “a few dollars”), plus 3D printing and soldering supplies | Yes, 3 axes | GSPro, E6/TruGolf |
| OpenFlight base (DIY) | Doppler radar | ~$534 per its README (OPS243-A radar $249, Pi 5 $130, 7” touchscreen $46, impact trigger $18, enclosure and power) | Experimental | GSPro via connectors |
| OpenFlight + angle radar | Doppler radar | ~$684 (adds TI IWR6843 $150); ~$819 with all extras | Experimental | GSPro via connectors |
| Shot Scope LM1 | Doppler radar, finished product | $199.99 across our tracked price snapshots since September 21 | No | None |
| PRGR HS-130A | Doppler radar, finished product | $199.99 across our tracked price snapshots since September 21 | No | None |
Two things stand out. First, the cheapest serious DIY build (PiTrac) costs more in parts alone than a finished entry radar, before valuing a build process its own docs call not easy. Second, OpenFlight’s base build at ~$534 lands in the territory where used or entry commercial units with full app ecosystems start appearing — so its appeal is the project, the AGPL-licensed code you can modify, and the community, not the savings.
The genuine value case is PiTrac versus the camera tier: three-axis spin measurement normally means a four-figure photometric unit, and PiTrac attempts it for a few hundred dollars in parts. If it holds up in your build, that is capability-per-dollar nothing commercial touches.
DIY metrics vs. a $199 pocket radar, honestly
A fair comparison has to start with what each side measures rather than estimates — the distinction our guide to how launch monitors work covers in depth.
The budget commercial radars measure very little, but what they measure, they measure directly. The PRGR HS-130A and Shot Scope LM1 each report five metrics, and per their spec sheets only two are measured: club speed and ball speed. Smash factor is derived from those, and carry and total distance are algorithm estimates — no launch angle, no direction, no spin. Top Shelf Golf’s testing found the PRGR’s ball speed within 1 mph of a Trackman, which is why it became a speed-training fixture despite the short metric list. The LM1 adds a 3.5-inch color screen, USB-C, app sync, and a flat no-subscription-ever guarantee per Shot Scope’s product page.
A completed PiTrac, per its documentation, captures ball speed, launch angles, and three-axis spin — a fundamentally richer picture of the shot than any sub-$500 commercial device reports. OpenFlight measures ball and club speed directly, adds measured launch angle only with the optional angle radar, and treats spin as experimental.
The honest caveats cut both ways. The commercial radars are consistent out of the box but hit a hard ceiling: no spin or launch data at any price, and reviewers note the PRGR’s accuracy drops on mishits and when misaligned. The DIY rigs have higher ceilings but no floor guarantee: your results depend on your build quality, lighting, alignment, and software version, and both projects say so themselves. Nobody warranties a PiTrac. The LM1 carries a two-year warranty per Shot Scope.
The simulator question: GSPro’s open door
The reason open-source launch monitors are viable at all is that the dominant third-party simulator software left the door open. GSPro publishes its Open Connect v1 API — a simple JSON-over-local-socket protocol documented at gsprogolf.com. Any device that can send ball speed, horizontal and vertical launch angle, and spin over that socket can drive GSPro. That is exactly the data a working PiTrac produces, which is why it lists GSPro and E6/TruGolf integration, and why OpenFlight ships simulator connectors.
The official spec is sparse (one page and a JSON example), but the community has filled the gap: projects like PinPoint Golf’s libgspro document the protocol in detail and implement both sides of it, per its GitHub repository. The practical upshot for a builder: the software integration is the solved part of the problem. Getting clean, repeatable ball data out of your sensors is the hard part.
Note what the open protocol does not get you: spin-less devices can’t meaningfully drive it. GSPro’s spec lists spin axis and total spin among required ball data fields, which is why neither the LM1 nor the PRGR — nor OpenFlight without its experimental spin — makes a satisfying sim engine. If simulation is the goal and DIY isn’t, the realistic starting point is covered in our launch monitor guide.
Who should build vs. who should buy
Build a PiTrac if you are comfortable soldering, 3D printing, and compiling on Linux, you want spin data without four-figure spend, and you’ll enjoy the project even when the current release is rough. The Discord and GitHub communities are active, and the parts bill is modest.
Build an OpenFlight if the radar approach, Python codebase, and AGPL community appeal to you more than the bottom line — at ~$534 base you are paying for the project, not saving money.
Buy a finished radar if you want numbers today. For pure speed training with zero friction, the PRGR’s standalone, no-app design is the benchmark; for the same $199.99 with a modern screen, app history, and a warranty, the LM1 is the 2026 pick. Both have sat at exactly $199.99 across our tracked price snapshots since September 21, so there is no discount timing to wait for.
And if “DIY launch monitor” led you here while planning a room build — screen, enclosure, mat, projector — that is a different project with its own budget math, covered in our DIY golf simulator build guide. The launch monitor is one line item in that build, and these open-source rigs can slot into it, but most home-build budgets are better served picking the sensor last.
The bottom line
The open-source launch monitor scene is real, active, and further along than most golfers realize — PiTrac delivering three-axis spin from ~$250 in Raspberry Pi parts is genuinely new territory, and GSPro’s open API means a successful build drives real simulation software. But both flagship projects honestly describe themselves as immature, and the build demands skills and patience a purchase doesn’t. If the project itself excites you, build. If you just want trustworthy numbers for practice, $199.99 buys measured ball and club speed in a finished, warrantied package, and no DIY rig currently beats that on certainty per dollar.
Frequently asked questions
Is PiTrac legal to build and use?
Yes. PiTrac is released under the GPL-2.0 open-source license on GitHub, so anyone can build one for personal use. You cannot sell assembled units as a closed product without honoring the license terms, and the project notes it is not affiliated with Raspberry Pi Ltd.
Can a DIY launch monitor run GSPro?
Yes, if the project implements GSPro's Open Connect v1 API — a documented JSON-over-socket interface published at gsprogolf.com. PiTrac interfaces with GSPro and E6/TruGolf per its documentation, and OpenFlight streams shots to GSPro through simulator connectors per its README.
Is building a launch monitor cheaper than buying one?
Usually not at the entry level. OpenFlight's own documented bill of materials is about $534 for the base build, and PiTrac's two Pi computers and cameras alone run around $250 before printing and soldering supplies — while finished radars like the Shot Scope LM1 and PRGR have held steady at $199.99 across our tracked price snapshots since September 21. DIY wins on capability per dollar only if your time is free and you want camera-grade data like spin.
What spin data can DIY launch monitors measure?
PiTrac determines spin in three axes using infrared strobe-based image capture, per its project documentation. OpenFlight's spin detection is radar-based and explicitly labeled experimental in its README — it is not used for carry calculations by default.