Calibration¶

The LD2450 radar's native coordinate system is distorted — it reports target positions relative to the sensor's own field of view, so straight physical lines (walls, the edge of a sofa) don't come back as straight lines. Calibration solves this by mapping four corners of your room to the corresponding sensor coordinates, producing a perspective transform. Once calibrated, targets sit where they actually are.

This page walks through running the calibration wizard.

Before you start¶

Device running Grid firmware and visible in the panel. See Flashing firmware if not.
A clear view of each of the four corners of the room. You need to be able to stand at each one (or at least close to each one — the wizard has an option for corners you can't reach).
One person in the room. The wizard picks up a single target and records its position; extras confuse it.

Tip

Pick real physical corners — where two walls meet. Don't use corners of furniture, rugs, or partial dividers.

Running the wizard¶

The wizard is accessed from the Device Configuration tab. Look for Start room size calibration (or Calibrate room size) — it lives in the device's settings/placement section.

1. Read the positioning guide¶

The first screen shows a diagram of a room with the four corners numbered 1–4 and the sensor marked (in the example diagram, the sensor sits at corner 2, but it can be anywhere). Skim the instructions, then click Start calibration.

Tick Don't show this again before clicking Start calibration to skip straight to corner marking on future calibrations. You can re-enable the guide from the integration's options under Show room calibration tutorial.

Screenshot placeholder

Wizard guide screen — room diagram with numbered corners and walking instructions. calibration/wizard-guide.png

2. Mark each corner in order¶

For each of corners 1 through 4:

Walk to the corner.
Click Mark {corner N}.
Stand still for about 5 seconds while the wizard records your position.

The wizard collects radar samples over that 5-second window and averages them, so small sways don't matter but real movement does. If you move during the capture, the wizard will say so and you can re-mark the corner.

Warning

Stay still during each capture. The wizard is averaging samples over 5 seconds; if you move, the corner position gets smeared and the resulting grid won't match the real room.

If a corner is unreachable (a plant in the way, built-in furniture), stand as close as you can and enter the side and front-back distances from the actual corner in the offset fields (in cm). The wizard will treat your position as the corner plus those offsets.

Screenshot placeholder

Wizard mid-capture — Mark Corner 2 button, 5-second recording progress bar. calibration/wizard-capture.png

3. Re-mark if anything looks off¶

After all four corners are captured, the wizard previews the computed grid over the sensor's field of view. Each corner is shown on the preview; click any of them to re-capture if a position looks wrong.

Screenshot placeholder

Wizard preview — all four corners marked, computed grid visible. calibration/wizard-preview.png

4. Save¶

Click Save. The wizard pushes the perspective transform and room dimensions to the device and the calibration is live.

Checking the result¶

After saving, open the live view in the Device Configuration tab and check:

Walls line up. The edges of the grid should follow the visible edges of your room's floor plan.
A real target tracks correctly. Walk a short path along a wall — the marker should stay along the grid edge rather than drift into the room.
No obvious skew. If the grid is visibly stretched, compressed, or rotated, one of the corner captures is probably off.

If something's wrong, re-open the wizard and re-capture the corner that looks off. You don't have to redo the whole calibration — just the bad corner.

Screenshot placeholder

Live view showing a real target tracking along a well-calibrated grid. calibration/live-view-calibrated.png

When to re-calibrate¶

Re-run the wizard if:

You moved or rotated the sensor — even a small angle change throws the transform off.
You rearranged the room significantly, particularly if furniture or walls near a corner moved.
You replaced the device with a different unit, even the same model — every sensor has slightly different manufacturing tolerances.

Troubleshooting¶

Symptom	Likely cause	Fix
Wizard shows "No target detected" during a capture	You're not in the sensor's field of view, or you're too still	Step into the middle of the room and wait a few seconds for the LD2450 to lock on before clicking Mark.
"Multiple targets detected" during a capture	Another person or pet is moving in the room	Be the only moving target in the room during calibration. Pets that won't move off the bed are also targets.
Corner position drifted during the 5-second capture	You moved mid-capture	Re-mark the affected corner. Stand still for the full 5 seconds; small sways are fine, walking is not.
Grid looks skewed or stretched after saving	One corner's captured position is off	Re-open the wizard and click the offending corner on the preview to re-capture it. You don't have to redo the whole calibration.
Targets drift across walls after calibration	Sensor is unexpectedly low, tilted, or moved since calibration	Verify the mount is still at 1.5–1.8 m height, tilted slightly down, and pointing into the room; re-run the wizard if the mount has shifted. See Placement.

See also: the central Troubleshooting page for conceptual FAQ and how to open a GitHub issue.

Where to next¶

With calibration done, you're ready to explore the live view. See Live view.