TURN A CHEAP STORE LAWN MOWER INTO A SELF-DRIVING ROBOT WITH CENTIMETER GPS ACCURACY
Replace a cheap mower's electronics with a Raspberry Pi and RTK GPS — it mows autonomously with centimeter accuracy and no boundary wire.
GardenRobotics
- difficulty
- ●●●●○
- time
- a long weekend
- license
- CC BY-NC-SA 4.0
- repo
- repo ACTIVE6,637 stars
●●●●○ · a long weekend · CC BY-NC-SA 4.0 · 6,637 stars · repo ACTIVE
WHAT YOU’LL NEED
- 3D printer + filament — printable parts — files are in the repo
- Electronic parts — full list with part numbers in the repo BOM
- Dev board / microcontroller — runs the project firmware
- Soldering kit + basic tools — one-time buy, serves every future build
Partner
COMPAREE VERDICT
OpenMower turns a €200 consumer robotic mower into a ROS-powered autonomous platform with RTK GPS. The result is genuinely impressive — it maps the garden, plans coverage paths, and mows with centimeter precision without any boundary wire. The catch is threefold: first, the non-commercial license means you cannot sell these or run a mowing service; second, you need a working RTK GPS base station (either your own or a subscription), which is an extra cost and setup step most builds gloss over; third, this is a proper ROS project with custom PCBs, firmware flashing, and Linux configuration — if you have never touched ROS or compiled a kernel module, budget double the time. The documentation is thorough and the community is active, but the single biggest mistake is underestimating the RTK setup. If you get that right, the mower works as advertised. The wiki is honest about what breaks (wheel encoders, GPS signal under trees) and how to fix it, which is rare and valuable.
IN THE REPO
NOT IN THE REPO
- —Full ROS stack, custom PCBs, STL files, assembly wiki and troubleshooting guides all present.
- —License is CC BY-NC-SA 4.0 — non-commercial use only, no selling the finished mower or offering it as a service.
- —You supply the base mower (YardForce Classic 500 or equivalent) — the project replaces everything inside it.
- —RTK GPS base station is required for centimeter accuracy; you can build one or subscribe to a correction service.
- —Active community forum and regular firmware updates.
- —No off-the-shelf kit — you source all electronics and print/order the PCBs yourself.
Can I build this?
Build at your own risk. Projects involve tools, electronics and sometimes mains voltage — follow the creator’s safety notes.
Partner · KickstarterHeyGears G1: 10M+ colors and transparent parts in one print, plus UV printing on flat objects. Figures, parts and labels — no painting.
Videos
OpenMower - The affordable Open Source DIY Smart GPS Robotic Mower
No official video from the creator. Community walkthroughs exist but are not linked in the repository.
Gallery
Start here
Navigation into the creator’s own docs — we don’t rewrite the guide, we route you to the source.
- 1.Read the compatibility page on the wiki to confirm your mower model is supported before buying anything.(YardForce Classic 500 is the reference model, but others work — check first.)
- 2.Order the custom mainboard PCB using the provided Gerber files.(JLCPCB or PCBWay, standard 1.6mm thickness, HASL finish is fine.)
- 3.Set up the RTK base station or sign up for an NTRIP correction service.(This is the step people skip and then spend a weekend debugging poor GPS accuracy.)
- 4.Follow the assembly guide in the wiki to gut the mower and install the new electronics.(Take photos as you disassemble — reassembly is easier with a reference.)
Resources
Documentation, files and community threads for this build — we link straight to the original sources and never rehost the creator’s files.
KNOWN ISSUES
- Buying a mower model that is not on the compatibility list — the hall sensor placement and motor controllers vary, and adapting it yourself is a multi-day detour.
- Skipping the RTK base station setup and expecting GPS accuracy to work anyway — it will not, and the mower will wander.
- Underestimating ROS setup time if you have never used it — the wiki assumes you can flash an image and SSH in, but the first-time learning curve is steep.
- Ordering the wrong u-blox module — it must be the ZED-F9P for RTK, not the cheaper M8 or M9 variants.
- Not calibrating the wheel encoders after assembly — the mower will think it is moving faster or slower than it is, and paths will drift.
- Mounting the GPS antenna too low or under tree cover — even RTK needs a clear view of the sky, and signal dropouts under branches are the most common complaint.
Can I use a different mower brand?
Maybe. The YardForce Classic 500 is the reference platform and the one the PCB is designed around. Other models require checking motor specs, hall sensor positions, and battery voltage — the wiki has a compatibility section, start there.
Do I need my own RTK base station or can I use a correction service?
Either works. A local base station you build yourself is a one-time cost but needs clear sky view and setup. An NTRIP subscription is easier but costs monthly. Both deliver the same centimeter accuracy once configured.
What happens if GPS signal is lost?
The mower stops and waits for signal to return. It does not have a fallback mode like random bouncing — RTK accuracy is the whole point, so without it, it parks.
Can I sell a finished mower or offer mowing as a service?
No. The CC BY-NC-SA license explicitly prohibits commercial use. You can build one for yourself, but monetizing it in any form violates the license.
Community builds
No community builds yet — be the first, we feature the best ones.
Discussion1
FROM THE COMPAREE TEAM
RTK GPS is the unlock here — but it also means you need a base station or a subscription before the mower will hit centimeter accuracy. Did you go local base or NTRIP service, and what surprised you about the setup?
Clemens Elflein
Clemens Elflein built OpenMower as a way to replace the boundary wire and random-bounce logic of cheap robotic mowers with proper autonomous navigation. The project started as a personal weekend build and grew into a full open-source platform with a community wiki, active forum, and regular firmware updates.
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DISCLAIMER
- Comparee is not the author of the projects featured here. All rights to each project belong to its creator — every page links to the original source, and we never host creators’ files.
- Information is provided without warranty and may become outdated as projects evolve. Prices are indicative bands only — always check the creator’s parts list for current costs.
- Building and operating any project is at your own responsibility. Protective equipment, safe workshop practice and compliance with local regulations are the builder’s responsibility.
CompareeTEAM27d agoedited
The repository is active and the wiki is thorough, but there is no official video walkthrough — the good build guides are community-made and scattered across YouTube and the forum. The single biggest trip-up is the RTK base station: people assume the GPS module alone is enough, but without RTK corrections, accuracy drops to meters instead of centimeters, and the mower's autonomous navigation falls apart. If you have never worked with ROS, budget extra time for the Linux setup and firmware flashing — the wiki assumes you are comfortable with the command line. The non-commercial license is clear in the repo but easy to miss if you are skimming.