Introduced in firmware 3.14.0
¶ What is Single Antenna Positioning Mode?
Yarbo Core normally uses two RTK antennas. Two antennas give it two things at once: where it is (position) and which way it's facing (heading).
Single Antenna Positioning Mode is a fallback that lets Yarbo keep working accurately when only one of those two antennas is usable. Position comes from the healthy antenna as usual, and heading is calculated from the robot's own movement instead of from the second antenna.
It turns on and off automatically. You don't need to enable anything, and there's no setting to configure.
¶ Why did we add it?
Because in real yards, one antenna losing signal is common — and until now, losing one antenna meant losing far more capability than it should have.
- The wall problem. When Yarbo mows along a wall, a fence, a hedge, or the side of the house, the antenna closest to that structure gets its view of the sky blocked. The other antenna is usually still fine. So the Core still knows where it is — but with only one antenna reporting, it no longer knows which way it's pointing. Same story in "canyon" environments: narrow side yards, tall tree lines, buildings on both sides.
- The damaged antenna problem. Antennas take hits. If one is broken, marginal, or otherwise not reporting reliably, the whole two-antenna advantage disappears with it.
- What used to happen. In both cases, Yarbo would fall back to pure dead reckoning (DR) — estimating its movement without satellite help. That works for a short stretch, but drift accumulates quickly, and it throws away the perfectly good signal still coming from the working antenna.
- What happens now. Instead of dropping all the way down to DR, Yarbo switches to Single Antenna Positioning Mode and keeps using the good antenna. As long as one antenna is healthy, Yarbo can still produce both accurate positioning and a usable heading.
¶ When exactly does Yarbo switch into this mode?
Automatically, when the Core determines that one antenna can be trusted and the other can't. Broadly:
- One antenna is damaged, disconnected, or otherwise unavailable, while the other holds a fixed RTK solution with high confidence.
- Both antennas are affected by multipath (signal bouncing off walls, roofs, vehicles), but one of them is still clearly the more reliable of the two.
It isn't tied to a specific antenna — left or right, Yarbo will use whichever one currently has the better signal, and switch back to normal dual antenna operation once both are healthy again.
¶ What will I see in the app?
Deliberately, very little. The intent is that your task keeps running rather than stopping to ask you about it.
- RTK signal still shows 4. There's no separate "single antenna" warning or alert.
- The task continues. No pause, no manual intervention needed.
- With PPVS enabled, the GPS icon shows a Deviation value and direction, in meters: green at 0.15 m or below, yellow above 0.15 m. This is your at-a-glance read on how tightly Yarbo is tracking its intended line.
¶ What Does the Number After "GPS" Mean with PPVS Enabled?
In Yarbo's status display, the number following "GPS" (in meters) represents the estimated positional offset between Yarbo's calculated position and its actual real-world location, after PPVS fusion positioning is applied.
📍 When the value reads 0.00M
This indicates that your GPS signal is in good shape. Yarbo is navigating using standard GPS and has not switched to Dead Reckoning (DR) mode.
📍 When the value is greater than 0
This means GPS signal has become unstable — for example, when Yarbo is operating under a tree or close to a wall. Rather than stopping, Yarbo automatically switches to DR mode, using its wheel odometer and gyroscope to continuously estimate its position and keep working.
⚠️ Important: This number does not represent how far Yarbo has traveled. It reflects the accumulated positional error in Yarbo's estimated location. The longer Yarbo operates in DR mode without recovering a stable GPS signal, the larger this offset value may become.
¶ What are the limitations?
Two antennas are still better. This is a resilience feature, not a replacement. If one of your antennas is damaged, please still contact support to get it repaired — the mode is there so a bad antenna doesn't stop your yard work, not so you can run indefinitely on one.
¶ Do I need to do anything?
No. Update to firmware 3.14.0 or later and it works in the background. If you notice your Deviation reading is consistently in the yellow, or Yarbo's behavior in a specific part of your yard doesn't look right, let our support team know along with the area and conditions — that kind of report is genuinely useful to us.