1. Detection Area vs. Stay Area
These two types of zones are not mutually exclusive; they are designed to work together hierarchically.
Detection Area (The Global Boundary): This is the active box of the sensor. If a person or motion is outside of this area, the sensor completely ignores it. Think of this as defining the physical walls of your room.
Stay Area (The High-Sensitivity Micro-Zone). This is a specialized zone inside your detection area meant for places where people are stationary (e.g., a sofa, desk, or bed). When a target enters this zone, the radar shifts its behavior to lock onto micro-movements like breathing or slight shifting to prevent the lights from turning off while you are sitting still.
How to configure them for a sitting room:
You should be overlapping them.
Set the Detection Area to encompass the whole room.
Draw a Stay Area directly over the couch or chairs where people sit.
2. Why your Stay Area numbers keep moving.
This is a known firmware/Zigbee2MQTT bug.
Community testing and visualizer tools have confirmed that the Stay Areas frequently invert, swap, or flip their left/right (Width min/max) coordinates across the Y-axis immediately after you hit apply.
If you notice the numbers jumping or swapping, try inputting them backwards (swapping your min and max width values) or re-applying the zone a second time. Users have to use tools like the Inovelli mmWave Visualizer add-on to manually fight the inversion until it sticks.
3. What is MmWaveStayLife?
MmWaveStayLife is essentially an independent “Hold Time” (or cooldown timer) specifically for the Stay Area.
Normally, the sensor uses MmWaveHoldTime to decide how long to wait after it stops seeing motion before declaring the room vacant. However, because sitting still makes it much harder for the radar to constantly track you, MmWaveStayLife gives the sensor an extended buffer.
What it means: It is the length of time a target stays detected after the sensor thinks you stopped moving inside that specific Stay Area.
Note on units: Depending on your firmware version, this value might be calculated in increments of 50ms (meaning a value of 300 equals 15 seconds) or in straight seconds. If your lights are turning off too quickly while you are sitting on the couch, you need to increase this number.
4. The Negative Depth Value Paradox (-100 to 600)
Zigbee2MQTT exposes the depth range as 0 to 600 (cm) because standard radar logic dictates that 0 is the face of the sensor, and everything in front of it is positive depth.
However, the hardware’s internal coordinate map allows you to configure a slightly negative depth.
Why is this possible? mmWave radar beams aren’t perfectly flat; they propagate out like a cone or a bubble. A negative depth allows you to capture “bleed-through” or targets that are slightly behind the plane of the wall switch if the sensor is recessed or angled.
Is it OK to do? Yes, it is perfectly fine. If you are tracking targets accurately at -100, you can safely set your zone depth minimum to -100. Just be aware that if you change your global “Room Size Preset” in the dropdown menu later, it will likely overwrite your custom negative values back to 0.
This is just my understanding and someone else may be able to more acurately/better discribe it.