Robotic mowers are a great thing, if it weren’t for the perimeter wire. Especially with more complex layouts and many obstacles such as shrubs, pools, trees, flower beds, etc., laying a perimeter wire is quite a tedious affair. It’s not uncommon to have to go troubleshooting when the wire has a break again.
Commercial robotic mowers with GPS/RTK are still very rare and also expensive. Husqvarna has had the EPOS system since 2020, which costs an RRP of 5,799 euros for the mower, plus 1,199 euros for the reference station, and is aimed at professional users.
Segway has announced the Navimow, which is expected to cost between 1,199 and 2,499 euros and could shake up the market - if it were already available. Originally, it was supposed to hit stores in the first half of 2022.
⚠ [affiliate] Keine Produkte mit Cache für default.
Bitte affiliate-sync --lang en ausführen.
There are also projects like the Ardumower with Sunray firmware and GPS/RTK support. This one also mows our lawn. The makers also offer a commercial version called the “ Alfred robotic mower ” that you can buy ready-made and whose chassis is based on a common platform.
OpenMower - Yardforce robotic mower converted
A very new project is the OpenMower by Clemens Elflein. It also relies on GPS/RTK navigation. As a platform, he uses the very affordable Yardforce robotic mowers. These offer ideal prerequisites, such as brushless motors for the cutting deck and drive, a waterproof housing with cutting height adjustment and overall very good build quality. The battery and charging station are also already included.
Clemens has developed a new mainboard for the Yardforce Classic 500 (and the Yardforce SA650ECO is also in progress) that replaces the original board. The existing connectors can simply be connected to the OpenMower board. Even the original control panel is supposed to remain usable.
Technically, the solution is right up my alley: A Raspberry Pi 4 is the heart of the system, providing plenty of computing power, interfaces and possibilities for expansions, API APIApplication Programming Interface – defined interface through which programs communicate. Home Assistant offers a REST and a WebSocket API (e.g. for MCP) , etc. The low-level tasks such as motor control, etc. are handled by a Raspberry Pico RP2040 microcontroller.
For GPS/RTK reception, the OpenMower also uses the ArduSimple kit , which unfortunately is still the most expensive item in the conversion and is also used in the Ardumower GPS/RTK project. Clemens has also developed his own ESCs (Electronic Speed Controllers).
The OpenMower is taught by driving around the mowing area and the exclusion zones. This is controlled with an Xbox controller. Once the mower has its map, it can mow systematically in lines using GPS control.
This already works. What is still missing at the moment is a user interface. Clemens also wants to provide a native iOS and Android app.
What’s even more interesting is that the OpenMower board could probably also be used to retrofit many other robotic mowers, as many are based on the same platform. For example, the Ferrex robotic mowers from Aldi are rebranded Yardforce robots, and the Ferrex 800 has the same board built in as the Yardforce SA650ECO.
The Yardforce SA650ECO can sometimes be had for under 300 euros. The simpleRTK kit had to be estimated at 800 euros. A Raspberry Pi 4 (if available at all at the moment) and the remaining components, I would estimate at 150 euros under normal circumstances. So you could realize a GPS robotic mower for a good 1,200 euros, based on a proven platform. With a bit of luck, you could then sell the original mainboard as a spare part on Ebay. Unfortunately, the chip crisis is currently hitting hard, so not only the OpenMower project is suffering because availability and prices have taken on bizarre proportions.
More info is available here: OpenMower - The DIY Smart Robot Mower for Everyone - x-tech.online. You can also order boards for the mainboard here.
The project itself is hosted on GitHub:
There is a separate repository for the software:
GitHub - ClemensElflein/open_mower_ros
If you want to participate and learn more, you can join the OpenMower Discord Server . The speed at which the project is being driven forward is certainly very impressive. Both hardware and software in the OpenMower are fully open source. I’m excited to see what will soon be possible.
You can support the project on Patreon: Clemens Elflein offers Open Source Projects, OpenMower, xESC, self-o-mat | Patreon
Hi! I'm Markus – the Fricklr. ⚡ Electrical engineer, 🎵 musician (bass, guitar, keys) and professionally 'something with the internet' 🌐 for over 30 years – nowadays with AI too 🤖 – a 55-year-old generalist from Bavaria, Germany.
Your feedback helps me write even more interesting posts. After "Yes" there's also a small option to support my work.
What do you think? Leave a comment!
Share your thoughts, questions or experiences with the community.