First impression
Upon installation, your setup should look similar to the screenshot:
Please don’t feel overwhelmed by the number of parameters this sensor provides. Most automations require only a few of them.
Turning lights on and off
One of the most basic and common uses of a radar presence sensor is turning lights on and off.
For this scenario, you need only one parameter — Presence.
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Turn lights ON when Presence becomes occupied
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Turn lights OFF when Presence becomes not occupied
That’s it.
Preventing lights from flickering on and off
A common scenario is entering and leaving a room briefly (for example, stepping out for a moment). In such cases, you may not want the lights to turn off immediately and then flicker back on.
To avoid this, use the Timeout parameter.
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Timeout defines how long the sensor waits before switching Presence from occupied to not occupied after detection stops.
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The default value is 5 seconds.
Example:
If you set Timeout to 30 seconds, the Presence state will change to not occupied only after 30 seconds of no detection. This helps keep lights stable and prevents frequent on/off switching.
Limiting detection distance
(avoiding false triggers)
Another common use case is triggering the sensor only when someone is within a specific distance.
The LD2410 series has a maximum detection range of 6 meters (20 feet). The sensor divides this range into distance zones called gates (Gate #0 through Gate #8).
The size of each gate is defined by the Distance Resolution parameter:
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Default value: 0.75 m
This means:
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Gate #1 is 0.75 m
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Gate #2 is 1.5 m
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Gate #3 is 2.25 m
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and so on
Example: restroom or small closet
Imagine a restroom or small closet built with drywall and located near a hallway or another walkable area. The room is 2×2 meters, and you want the lights to turn on only when someone is inside the room. Radar waves can penetrate drywall, so the sensor may detect people walking outside the room, causing false triggers (detection range is 6 meters).
To prevent this, you can limit the detection range:
Set Max Move Distance Gate to 3
Set Max Still Distance Gate to 3
With the default distance resolution (0.75m):
0.75 m × 3 = 2.25 meters (≈7.4 feet)
This means the sensor will ignore movement and presence beyond 2.25 meters, helping eliminate false positives from outside the room.
Engineering Mode
(advanced control)
Sometimes you may notice the sensor triggering too often or not being sensitive enough. In such cases, you can fine-tune its behavior using Engineering Mode.
Engineering Mode basics
After enabling Engineering Mode, the sensor will start reporting Moving and Still Energy values.
Each value ranges from 0 to 100:
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Higher values mean a stronger movement or presence signal
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Lower values mean weaker or no detection
Gates and energy values
As mentioned earlier, the maximum detection range (6 meters) is divided into zones called Gates, from Gate #0 to Gate #8.
For each gate, the sensor reports separate moving and still energy values.
By adjusting the Move Threshold and Still Threshold sliders, you control how strong a signal must be before the sensor reports movement or presence.
The sensor will only trigger detection if the measured energy value exceeds the threshold set for that specific gate.
⚠️ Although these thresholds provide advanced control, we do not recommend spending too much time tuning them unless you have a specific issue to solve.
Important things to keep in mind
Depending on the sensor’s positioning, radar waves can penetrate walls, ceilings, and floors, so detections may come from sources you don’t immediately expect. For example:
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People moving behind a wall or in a neighboring apartment
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Movement upstairs or downstairs
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Running water in a toilet
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Ventilation or ceiling fans
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Moving curtains or hanging objects
These are not necessarily sensor faults, but normal behavior for radar-based detection.
Auto-calibration (recommended before manual tuning)
If you are still confident the sensor is too sensitive, try auto-calibration using the HLKRadarTool mobile app:
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Install HLKRadarTool on your phone
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Connect to the sensor via Bluetooth
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Leave the room and make sure nothing is moving
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Press the Initialize button
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Wait until the auto-calibration process finishes
This allows the sensor to recalibrate itself to the environment and often resolves sensitivity issues without manual tuning.