OpenMower-V2 Carrierboard for SABO Mowers
May 25, 2026 · View on GitHub
About This Repo
OpenMower is an open-source project that upgrades off-the-shelf robotic mowers into modern, smart lawn mowing robots with RTK GPS technology. For more details, check out the OpenMower project.
This repository contains the design files for a custom carrierboard specifically designed for converting SABO based mowers to OpenMower V2.
For more info or questions, please visit Discord
List of Compatible Mowers
This Carrierboard is compatible with the following mower models:
- SABO MOWit 500F (Series-I & II)
- John Deere Tango E5 (Series-I & II)
| Series-I Carrierboard (v0.2) | Series-II Carrierboard (v0.2) |
|---|---|
 |  |
| Series-I (v0.1) @ John Deere Tango E5 | Series-II (v0.1) @ Sabo MOWiT 500F |
 |  |
Required Additional Components
To build a complete OpenMower-V2 system, you will need the following additional components beyond this Carrierboard:
Essential Components
- 1 * xCore: OpenMower-V2 Development Board for all Low-Level processing
- 1 * Raspberry Pi CM4: System on Module (SoM) for OpenMowerOS, ≥ 4GB RAM, ≥ 16GB Storage (eMCC or SD-Card)
- 3 * xESC mini: Electronic Speed Controller for BLDC motor
- 1 * WT-RTK-960: RTK GPS Module for precise positioning
- 1 * HA/HX-901: GPS Helix Antenna or similar
Optional Components
- MicroSD Card: High-quality MicroSD-Card (≥ 16GB) for OpenMowerOS if CM4 is without eMCC
- RTK Base Station: If you've no public NTRIP service at your location
Installation
See Robot Specific Guide in the official docs.
The old instructions are still here: INSTALL-HARDWARE-AND-SOFTWARE-PREP.md.
LCD
Click the button above to watch the Sabo LCD demonstration video
Meaning of the LEDs
| LED | Meaning |
|---|---|
| Auto |  In autonomous mode,  "Hanging around" indicator due to pause or error |
| Driving/Mowing | Mowing or navigating, Paused |
| House/Home | Navigating to dock/home |
| Start/Play |  Emergency,  Waiting for ROS Docked & charging finished, Docked & charging,  Docked but no or faulty battery |
Meaning of the Buttons
The meaning of the buttons is context driven
Meaning of the Buttons in IDLE context
| Button | Series-I | Series-II | Short Press | Long (≥0.5s) Press |
|---|---|---|---|---|
| Auto | :x: | :white_check_mark: | ||
| Driving/Mowing | :x: | :white_check_mark: | Start mowing | |
| House/Home | :x: | :white_check_mark: | ||
| Select (left) | :white_check_mark: | :x: | ||
| Start/Play | :white_check_mark: | :white_check_mark: | Start mowing | Clear emergency |
Meaning of the Buttons in any autonomous mode (mowing, docking, ...)
| Button | Series-I | Series-II | Short Press | Long (≥0.5s) Press |
|---|---|---|---|---|
| Auto | :x: | :white_check_mark: | ||
| Driving/Mowing | :x: | :white_check_mark: | Skip path | Skip area |
| House/Home | :x: | :white_check_mark: | Go back home/dock | |
| Select (left) | :white_check_mark: | :x: | ||
| Start/Play | :white_check_mark: | :white_check_mark: | Pause/Continue mowing | Clear emergency |
Roadmap
- Hardware
- Power/Dock
- Networking
- Charger
- ESCs (BLDC Motors)
- Emergency sensors (Front Wheel Lifts, Top-Stop, Handle-Stop)
- Battery interface (I²C)
- CoverUI (Series-I)
- Buttons
- LEDs
- LCD Backlight
- LC-Display
- CoverUI (Series-II)
- Buttons
- LEDs
- LCD Backlight
- LC-Display
- Software
Additional Information
This Carrierboard includes more features than actually required to build an OpenMower robot. Additional features include a gigabit Ethernet switch, LiPo charger, and a 12V auxiliary power supply for extensions.
History
Carrier versions
| Version | Date | Info |
|---|---|---|
| v0.5.0 | 2026/07 | In Development - Add Mow-ESC-Fuse for power ESCs - Slightly improve power traces - Improve mow-phases for 9A - Lower chargers FB divider to target a VBAT of 28.28V - Add BMS-I2C swapper via solder jumper - Custom BMS plugs for DALY or JBD (UART7) - Optional 6-9A charge current via Fsw 200kHz solder jumper |
| v0.4.0 | 2026/05 | - Fix and improve v0.3.0 issues - Skip one GPIO expander and switch to smaller footprint - Rearrange LAN and USB Plug as well as skip 2nd optional LAN in favor of more space for Series-I plugs |
| v0.3.0 | 2025/11 | Internal Prototype - Fix Series-I/II emergency incompatibilities - Improve CoverUI circuit - Improve Series-I CoverUI plug accessibility |
| v0.2.1 | 2025/06 | - Add DCDC-In current sense and allow charge currents up to 2.8A - BMS data support |
| v0.2.0 | 2025/06 | - Fix Series-II emergency oscillation issues - Support Series-I LEDs and Buttons - Support LCD |
| v0.1.0 | 2025/03 | Initial Prototype |
Patents, Local Laws, Liability
Before building a robot based on the designs published here, please make sure that you are allowed to do so in your specific regions. There may be patents and / or laws prohibiting you of doing so.
The code/schematics/PCB files are distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
This basically means: I'm just documenting a project of mine here for free and I don't have the time and resources to check that devices built using this information will be safe to use, legal to use or even work as intended. You will need technical know-how to use this project and I'm not liable for any damages your devices do to anyone or anything.
The RoHS mark on the PCB indicates presumed compliance based on supplier declarations. No third-party testing or certification has been conducted.
License
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.