For a hallway or front door, a PIR sensor is often the better choice. For a bedroom, office, or living room where you need the lights and HVAC to respond to whether someone is actually present, mmWave is worth the extra cost and setup time.

Which mmWave Sensor Works Best with Home Assistant in 2026?

The right sensor depends on your integration path. Here are the three most practical options:

1. Aqara FP2 (Wi-Fi, Multi-Zone)

The FP2 connects over Wi-Fi and supports up to 30 detection zones with x/y coordinate output. It integrates with Home Assistant via the official Aqara integration (since HA 2023.8). No soldering, no ESPHome. If you want a polished out-of-box experience and don't mind $65-$80, this is the one. Range is rated to 8 meters with a 120-degree field of view. The zone configuration happens in the Aqara app, which is a minor friction point.

2. Zigbee mmWave Sensors (ZY-M100, ZM-35H-20)

Several manufacturers produce Zigbee-based mmWave sensors that pair with Zigbee2MQTT or ZHA. The Tuya ZY-M100 is widely supported and costs around $20-$30. It reports occupancy, illuminance, and distance as separate entities in HA. Range is typically 5-6 meters. These are good if you already have a Zigbee coordinator and want to stay in that ecosystem.

3. ESP32 + HLK-LD2410 (DIY, Maximum Control)

The HLK-LD2410 is a 24 GHz module from Hi-Link that costs about $5-$8. Pair it with an ESP32-C3 or ESP32-S3, flash ESPHome, and you get full control over sensitivity, detection gates, and update intervals. This is the path most software developers take because the ESPHome YAML config is readable, the entity data is rich, and you can tune the sensor behavior to your specific room geometry. [LINK: hlk-ld2410-esp32-kit]

Step-by-Step: Setting Up an ESP32 + LD2410 mmWave Sensor with ESPHome

Step 1: Wire the LD2410 to Your ESP32

The LD2410 communicates over UART. Connect it to your ESP32 as follows:

• LD2410 VCC to ESP32 3.3V
• LD2410 GND to ESP32 GND
• LD2410 TX to ESP32 RX pin (e.g., GPIO16 on most boards)
• LD2410 RX to ESP32 TX pin (e.g., GPIO17)
• LD2410 OUT pin to any GPIO if you want the hardware presence output (optional when using UART)

The LD2410 runs on 3.3V and draws about 80-130 mA during operation. Keep your USB power supply rated for at least 500 mA to be safe.

Step 2: Create an ESPHome Config

In Home Assistant, open the ESPHome add-on and create a new device. Paste this configuration, adjusting GPIO pins and your Wi-Fi credentials:

esphome:
  name: office-presence
  friendly_name: Office Presence Sensor

esp32:
  board: esp32dev
  framework:
    type: arduino

wifi:
  ssid: !secret wifi_ssid
  password: !secret wifi_password

api:
  encryption:
    key: !secret api_key

ota:
  password: !secret ota_password

uart:
  id: ld2410_uart
  tx_pin: GPIO17
  rx_pin: GPIO16
  baud_rate: 256000
  parity: NONE
  stop_bits: 1

ld2410:
  id: ld2410_radar
  uart_id: ld2410_uart

binary_sensor:
  - platform: ld2410
    has_target:
      name: Presence Detected
    has_moving_target:
      name: Moving Target
    has_still_target:
      name: Still Target

sensor:
  - platform: ld2410
    moving_distance:
      name: Moving Target Distance
    still_distance:
      name: Still Target Distance
    moving_energy:
      name: Moving Target Energy
    still_energy:
      name: Still Target Energy
    detection_distance:
      name: Detection Distance

This gives you five sensor entities and three binary sensors in Home Assistant. The has_target binary sensor is your primary presence indicator.

Step 3: Flash and Adopt

Click Install in ESPHome, choose your connection method (USB first time, OTA after that), and wait for the flash to complete. Home Assistant will automatically discover the device via the ESPHome integration. Accept the adoption prompt and your entities will appear.

Step 4: Tune Sensitivity Gates

The LD2410 divides its detection range into gates, each covering approximately 0.75 meters. Gate 0 is closest to the sensor, gate 8 is furthest. You can configure sensitivity per gate to reduce false positives from, for example, a fan or curtains moving in the background.

Add this to your ESPHome config to expose gate sensitivity as numbers you can adjust from the HA UI:

number:
  - platform: ld2410
    timeout:
      name: Radar Timeout
    max_move_distance_gate:
      name: Max Move Distance Gate
    max_still_distance_gate:
      name: Max Still Distance Gate
    g0_move_sensitivity:
      name: Gate 0 Move Sensitivity
    g0_still_sensitivity:
      name: Gate 0 Still Sensitivity
    # Continue g1 through g8 as needed

Start with default sensitivity (50 out of 100) and adjust up or down based on real-world testing in your room.

Step 5: Build a Presence Automation in Home Assistant

Here's a basic automation that keeps lights on while presence is detected and turns them off 2 minutes after the last detection:

alias: Office Lights Presence Control
description: mmWave-based presence automation
trigger:
  - platform: state
    entity_id: binary_sensor.office_presence_sensor_presence_detected
condition: []
action:
  - choose:
      - conditions:
          - condition: state
            entity_id: binary_sensor.office_presence_sensor_presence_detected
            state: "on"
        sequence:
          - service: light.turn_on
            target:
              area_id: office
      - conditions:
          - condition: state
            entity_id: binary_sensor.office_presence_sensor_presence_detected
            state: "off"
            for:
              minutes: 2
        sequence:
          - service: light.turn_off
            target:
              area_id: office
mode: restart

The 2-minute delay buffer prevents the lights from cutting out during brief sensor gaps. Adjust to taste.

Step-by-Step: Setting Up a Zigbee mmWave Sensor (ZY-M100)

If you'd rather skip the soldering, the Zigbee path is straightforward. Pair the ZY-M100 with your Zigbee coordinator using the standard pairing process (hold the reset button until the LED blinks rapidly). In Zigbee2MQTT, it will appear automatically and expose these entities to Home Assistant: occupancy (binary), illuminance_lux (sensor), and target_distance (sensor).

The ZY-M100 uses a 24 GHz radar module and has a configurable sensitivity and distance via Zigbee2MQTT's exposes interface. No custom firmware required. [LINK: zy-m100-zigbee-sensor]

Troubleshooting mmWave Presence Sensors in Home Assistant

Sensor reports presence when nobody is there

Lower the sensitivity on gates closest to objects that move, like HVAC vents, fans, or windows with curtains. On the LD2410, try reducing still_sensitivity on gate 0 and gate 1 to around 20-30. On Zigbee sensors, reduce the sensitivity setting via Zigbee2MQTT.

Sensor misses still occupancy

Make sure the sensor has line-of-sight to where you sit. The LD2410 has a roughly 60-degree cone. Mounting angle matters significantly. Tilting it slightly downward toward where people sit improves still detection. Also check that your detection distance gate covers the distance from sensor to chair.

ESPHome device goes offline frequently

This is almost always a power issue or a weak Wi-Fi signal at the sensor location. Try a different USB power supply with a higher current rating. If the device is far from your router, consider a Zigbee sensor instead or add a Wi-Fi access point closer to the room.

Distance values look wrong

The LD2410 reports distance in centimeters via UART. If values seem inconsistent, check your baud rate setting. The LD2410 default is 256000 baud, and mismatches here cause garbage data that ESPHome will partially parse incorrectly.

Why Software Developers Are Choosing mmWave Presence Detection

The appeal for developers is straightforward: mmWave sensors expose structured, continuous data rather than a simple motion boolean. The LD2410 reports moving energy, still energy, and distance at roughly 10 Hz. You can log this data, visualize it, and write automations that respond to where in a room someone is sitting, not just whether the room is occupied.

ESPHome makes this approachable because the configuration is declarative YAML. If you can read a REST API spec, you can read an ESPHome config. The HA entity model maps directly to the kind of state management developers already think about. It's a short conceptual bridge from writing software to writing firmware, especially with the LD2410 component handling all the serial protocol parsing for you.

Several developers have built multi-sensor room models that track occupancy zones independently, using two or three LD2450 sensors (the multi-target successor to the LD2410) to triangulate position in larger rooms. The LD2450 reports up to three simultaneous targets with x/y coordinates. That's the kind of data you can feed into a room presence model with real spatial awareness. [LINK: hlk-ld2450-multi-target-sensor]

FAQ