LD2410 Case: 3D Print Enclosures, Kits and Adding a Light Sensor

Two measurements matter. The first is the gap between the antenna and the inner face of the cover: Hi-Link suggests one or one and a half wavelengths when space allows, which at 24.125GHz means 12.4mm or 18.6mm, within ±1.2mm. The second is wall thickness.

• Half-wavelength thick: Hi-Link's first choice, measured inside the material, with ±20% tolerance.
• Very thin: if half a wavelength will not fit, go to one-eighth of a wavelength or thinner.
• In between: the thicknesses to avoid, since reflections are strongest there.

Wavelength inside plastic is shorter than in air, by the square root of the material's dielectric constant, so the ideal half-wave thickness depends on your filament. Common printing plastics come out at a few millimetres. If you do not know your filament's value, print the front thin, around a millimetre, and keep the gap.

The full radome figures sit alongside the spec table in the datasheet walkthrough.

The original and the B are slim 7x35mm strips, happy in a wall plate or a narrow bezel. The C is a 16x22mm square that pairs well with a XIAO-sized controller in a box barely larger than a matchbox. The B-P has pins already fitted, so allow height for Dupont housings.

1. Orient the antenna side toward the room; the components face the back.
2. Leave the gap from the radome section in front of the antenna.
3. Route the cable out of the back or bottom, not across the antenna face.
4. Add a slot or vent if an ESP32 shares the box; Wi-Fi boards run warm.
5. Include a screw or keyhole mount so the sensor cannot wobble.

• Good filaments: plain PLA, PETG, ABS, ASA.
• Avoid in front of the antenna: carbon-fibre-filled, metal-filled and silk or sparkle filaments with metallic content.
• Avoid: metal screws or inserts directly in the beam.

Community case designs for LD2410 boards with ESP32, D1 Mini and XIAO controllers are plentiful on 3D-printing sites. Search by your exact board and controller pairing, check the stated board version, and print one before a batch. Wiring for each controller is in the ESP32 and Arduino guide.

You have two routes. Some LD2410 firmware includes a light function tied to a light reading on the module, with a threshold from 0 to 255; ESPHome exposes it as the light sensor, the light_threshold number and the light_function select, where the board and firmware support it. The more predictable route is a dedicated I2C sensor on the same ESP32.

i2c:
  sda: GPIO21
  scl: GPIO22

sensor:
  - platform: bh1750
    name: Illuminance
    address: 0x23

• BH1750: cheap and well supported in ESPHome, reports lux.
• VEML7700: wide range and close to the eye's response; also in ESPHome.
• Placement: the light sensor needs a window or a light-permeable front; the radar does not.

Keep the light sensor away from the ESP32's status LED and from the lamp it controls, or the automation switches itself off. A small window facing the room, rather than the ceiling light, gives the most useful reading.

If you would rather buy than build, the Litos v3 pairs a radar with a VEML7700 behind a light-permeable printed front, and the SONOFF SNZB-06P24 adds a light sensor to a Zigbee presence sensor.

The AKAMATIS v2.2 is the most complete. It pairs an LD2410B with a Seeed ESP32-C3 and an external antenna, is powered over USB-C, and arrives with ESPHome firmware. It needs Home Assistant; without it, the sensor has nothing to talk to.

• Pick the test kit if you want to learn the radar first.
• Pick the C with cables for your own printed design.
• Pick the finished sensor if the case is the part you would skip.

A finished sensor also settles the radome question for you, since its maker has designed the front for the radar. For a DIY build, the ESPHome YAML walkthrough gets the controller side running.

Multi-room plans change the maths. A 3- or 4-pack of C modules plus one proven printed design is the cheapest way to cover a house, and every sensor ends up identical, which makes tuning faster from the second room on.

• Plastic wall plates: fine; check the gap and thickness as for a printed case.
• Wood panels and shelves: pass the signal with some loss; thinner is better.
• Metal back boxes: keep the antenna proud of the metal, facing out.
• Glass: passes 24GHz, but coated low-energy window glass can block it.

Height and angle follow Hi-Link's guidance: 1.5–2m on a wall, or 2.6–3m on a ceiling. Inside a case, a slight downward tilt on a wall mount aims the ±60° cone at seated people rather than the ceiling.

Shield the back if the case sits on a shared wall. Aluminium or copper foil on the inside of the case back, insulated from the pins, cuts the rear lobe that otherwise sees the next room. The range and shielding guide covers the side-foil trick for narrowing the beam.

Once it is mounted, retune. The case, the wall and the furniture all change gate energy slightly, and thresholds set on the bench rarely fit the final spot.