When you receive your Meross Presence Sensor Thread, it is recommended to first download the Meross App, connect the device via Bluetooth, and follow the in-app instructions to complete pairing and initial setup. During this process, the device will perform an Auto Adjust based on the current environment (such as room layout, installation position, and potential interference sources). This step is very important, as it establishes the baseline detection model and directly affects detection accuracy and stability.

Note:

• All settings adjustments must be made via Bluetooth connection to the Meross App.

• You can wake up the Bluetooth connection by changing the device detection state or pressing the top button on the device. (Bluetooth cannot stay continuously connected in order to reduce power consumption, as core data communication uses the Thread protocol.)

1. Detection Mode

On this page, Sensor Readings display the real-time detection status of Radar and PIR (Presence / Absence).

The device provides three detection modes:

• Radar with PIR Assist (Recommended) Highest accuracy. Radar is primary, PIR assists. Balances accuracy and stability, suitable for most scenarios.

• PIR with Radar Assist More power-efficient, but detection accuracy and stability are slightly reduced.

• Radar Only Uses only radar, suitable for stable environments with minimal interference.

2. Range & Sensitivity

This page is used for fine-tuning the detection area and trigger logic. It is the core setting affecting detection performance and includes: Range, Auto Adjust, Mode, and Threshold.

If there was interference during the initial setup (such as people moving), it is recommended to run Auto Adjust again on this page to obtain more accurate baseline parameters.

The system provides three preset sensitivity levels (Mode) for quick use in most scenarios. However, these presets are only general references.

To achieve higher detection accuracy, it is recommended to:

• Adjust the detection range to exclude interference areas

• Customize the threshold values to optimize trigger and maintain logic

2.1 Range

You can exclude interference or limit the detection area by masking specific zones.

• Tap an area to turn it gray → the area is masked (excluded from detection)

• Commonly masked areas include: curtains, air conditioner vents, hallways outside the door, etc.

As shown in the example:

• 0–3.2 m is shown in orange → Presence detected

• 3.2–5 m → Absence

• 5–6 m → Masked (gray), detection results in this area are ignored

⚠️ Note: Detection distance is not strictly linearly mapped to the UI scale. It should be judged based on actual environment and data.

Common interference sources: https://www.meross.com/en-gc/FAQ/739.html

Detection range reference: https://www.meross.com/en-gc/FAQ/779.html

2.2 Sensitivity & Threshold

After clicking “Start,” you can view real-time detection data:

• Bar chart: current signal strength

• Blue line: current threshold (Threshold)

• Above threshold → Presence (orange)

• Below threshold → Absence (light blue)

• Gray area → masked area; detection results in this area are ignored

Two key thresholds:

• Presence Trigger Threshold Determines whether the device can enter the “Presence” state

  • Higher value → harder to trigger presence

• Presence Maintain Threshold Determines whether the device can remain in the “Presence” state

  • Higher value → easier to fall back to absence

Example 1: False Absence when staying still (Missed Detection)

Scenario: When you are sitting still, the device occasionally or frequently switches to Absence

Observation:

• Focus on Presence Maintain Threshold

• The bar chart (signal) is often below the Maintain threshold line

Cause: Maintain threshold is too high, so presence cannot be maintained

Adjustment: Lower the Presence Maintain Threshold (move the blue line down)

Example 2: Presence not triggered when someone is present

Scenario: You enter the room or make slight movements, but the device does not switch to Presence

Observation:

• Focus on Presence Trigger Threshold

• The bar chart does not reach the Trigger threshold line

Cause: Trigger threshold is too high, so presence cannot be triggered

Adjustment: Lower the Presence Trigger Threshold

Example 3: False Presence when no one is present

Scenario: The room is empty, but the device still shows Presence

Observation:

• Focus on Presence Trigger Threshold

• Interference signals (bar chart) exceed the Trigger threshold

Cause: Trigger threshold is too low, making the device too sensitive to environmental interference

Adjustment: Increase the Presence Trigger Threshold Or use Range to mask interference areas

Example 4: Frequent state switching (Unstable detection)

Scenario: The state frequently switches between Presence and Absence

Observation:

• Focus on Presence Maintain Threshold

• The bar chart fluctuates around the threshold line

Cause: Maintain threshold is too close to the current signal, lacking stability margin

Adjustment: Lower the Presence Maintain Threshold appropriately (to stabilize presence state)

3. Sensor Configuration

This section controls multi-sensor behavior and the time logic of state determination, directly affecting response speed and stability.

• Absence Duration = determines how long after leaving before turning off devices

• Presence Duration = determines how long after arriving before turning on devices
  
  

3.1 Absence Duration

Controls how long after detecting “absence” before the device reports it.

• Shorter time:

  • Devices (e.g., lights) turn off faster after leaving

  • Higher risk of false absence (may turn off while someone is still present)

  • ? Recommendation: set to 30 seconds or more in daily scenarios to reduce false absence

• Longer time:

  • Lower risk of misjudgment, more stable detection

  • Slower response, possible delay in turning off devices

3.2 Presence Duration

Controls how long continuous activity must be detected before reporting “presence”.

• Shorter time:

  • Faster response, suitable for hallways, closets, and other instant-trigger scenarios

  • ? Recommendation: not longer than 2 seconds

  • May be falsely triggered by pets, curtains, etc.

• Longer time:

  • Filters short disturbances, improves accuracy

  • Slight delay in reporting presence; presence may not trigger immediately when entering the area

3.3 Multi-Sensor Distance

For multi-sensor setups, you can adjust the distance between sensors to avoid interference.

For detailed setup instructions, please refer to the video below.