Alexander Grau has announced the latest release of the Ardumower — a u-blox F9P-based, Arduino-compatible smart mower system, which in its latest release, supports real-time kinematic (RTK) positioning.
"Proud to show you our new GPS RTK Ardumower DIY kit," Grau writes on Twitter of the launch. "No wires, no cables — simply cm-precise GPS. You can define where to mow and how. What a surprise to see this heart the next morning from your window?"
Where previous Ardumower systems have required a perimeter wire to prevent the mower going off-course, the new variant — dubbed Sunray — uses real-time kinematic (RTK) positioning in its place. "RTK-GPS uses two GPS receivers, one for the reference antenna (base) and one for the robot mower (rover) which both communicate in real time via radio modules," the project explains.
"The base constantly sends correction data so the rover can compute its cm-precise (relative) position. In the RTK-GPS kit, everything required (receivers, radios, antennas etc.) is included. Also, if you don't want to operate your own RTK base, you can use an external base service via Internet (e.g. like Germany's SAPOS). This will reduce the hardware cost by about a half."
The Sunray upgrade, described as being in "experimental" form, comes as a firmware update compatible with the existing Ardumower chassis design and version 1.3 of the PCB, which is itself driven by an Arduino Due microcontroller. To this, the RTK hardware is added along with a Bluetooth 4.0/BLE UART module and a smartphone for configuration.