JMT HLK-LD2410-AA Test Kit

Like the D, the AA is a stationary presence sensor. Its hardware is minimal and its firmware is built around micro-motion, so it reports three states of a person in the room:

• Physical activity: walking, moving around.
• Slight movement: typing, shifting in a chair, gesturing.
• Rest: sitting or lying still, where a PIR sensor gives up.

The 9m figure is for moving people. Detecting someone completely still depends on the micro-motion signal, which is weaker than the return from a walking body, so the dependable range for rest is shorter. Plan the room around the spots where people sit, and check those with the sensor in place.

Where the extra reach earns its keep:

• A lounge where the sofa is 6 or 7m from the only sensible mounting wall.
• Halls and landings where one sensor should cover the full length.
• Workshops and garages with a bench at the far end.

Mounting choices by space:

1. Standard room, 2.4–3m ceiling: ceiling or wall both work. The ceiling keeps the cone off doors and windows.
2. High ceiling, 3–6m: the ceiling is the AA's strength. Mount centrally, antenna face pointing at the floor.
3. Long, narrow room: wall mount at one end, pointing along the length, to use the 9m reach.
4. Stairwell: ceiling at the top, looking down the flight.

At height, the distance from sensor to person grows fast. Someone sitting on a sofa under a 5m ceiling is already around 4m from the radar before any sideways distance, so the AA's reach is what makes a high mount practical at all.

Installation habits that avoid false presence:

• Keep the antenna face clear of metal fittings, light housings and ducts.
• Stay away from ceiling fans; on a high ceiling they often hang right next to the best spot.
• Do not aim a wall-mounted AA at windows with blinds that move in a draught.
• Run power cleanly; long supply runs up to a high ceiling need a stable supply at the sensor end.

How cone angle and distance combine is explained on range and field of view. For a case that fits a ceiling rose or a surface box, see the LD2410 case notes.

That split fixes the classic presence-sensor dilemma. With a single threshold, a setting sensitive enough to hold a still reader also triggers on a fan or a curtain; a setting strict enough to ignore the fan drops the reader. Separate values let you ask for a clear signal to start presence and accept a faint one to keep it.

• Trigger high: ignores brief noise and pets passing the edge of the cone.
• Hold low: keeps presence while someone breathes quietly on the sofa.
• No-one delay: a timeout after the hold signal fades, before the room reads empty.

The AA takes these settings over Bluetooth or the serial port, with multi-level parameter adjustment for changing scenes. A sensible order:

1. With the room empty, raise the trigger threshold until nothing starts presence.
2. Sit still at the farthest seat and lower the hold threshold until presence stays.
3. Set the no-one delay to cover short pauses, a minute or two for a lounge.
4. Cap the maximum distance at your far wall.

Do not assume the AA speaks the LD2410C's command set. Check the frame format and baud rate against Hi-Link's LD2410-AA manual before pointing an existing library or the stock ESPHome ld2410 component at it. The GPIO output needs no protocol at all, so it is the quickest way into Home Assistant while you work out the UART.

For the configurator, open the HLKRadarTool and PC tool notes; confirm the tool version supports the AA before you connect.

Choose the AA when:

• The people you want to detect sit more than 5 or 6m from any mounting point.
• The ceiling is higher than 3m.
• False triggers from fans or pets have beaten a single-threshold sensor.

Choose something else when:

• The room is small. The LD2410C covers it, works with stock ESPHome and tunes from a phone.
• You need batteries. The LD2410S runs from 3.3V at very low current.
• You want ceiling coverage of normal rooms in bulk. The LD2410D comes in 3- and 4-packs.

Before you commit a design to the AA, use the kit to settle three things: that the moving range and the still range both reach your seats, that the ceiling height you plan works in your space, and that your software can read its UART or GPIO output. Once those pass, the design is ready.

Family figures side by side are on the datasheet summary, and the main versions are compared on the version comparison. For raw position tracking across a big room, compare the LD2410 and LD2450.