Difficulty: starter

What does a Motion (PIR) sensor look like?

A Browan Motion device is a small device with a protruding PIR sensor.

• One side provides information on

  • unique device ID

  • device type

  • a link to these support pages

  • a QR code that also provides information on device ID, device type, batch etc

• the other side has the Spacewell logo embossed

Unboxing

A Browan Motion sensor is shipped in boxes of 10 devices. Each devices is already clicked into a holder.

Next to 10 devices in their holders, we also provide

• 10 screws. Holders can be screwed or attached to ceilings or desks with tape.

• 10 caps in case of desk installation, see Motion sensor | Why do some Spacewell Motion (PIR) sensors have a cap?

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How does a Motion (PIR) sensor work?

Spacewell motion sensors are Passive Infrared (PIR) sensors, that are triggered depending on changes in infrared light radiating from objects in its field of view. In layman's terms this means that they can be triggered by anything that moves and emits some kind of temperature: this could be a person, or your office dog.

As soon as they detect movement in combination with a change of temperature (for example if you enter a meeting room), the sensor is triggered and a signal is sent to Spacewell Workplace, indicating that this location is now occupied.

Technical

The wireless motion sensor (TBMS100-915) is produced by Browan. The sensor utilizes LoRaWAN connectivity to communicate the presence or not of a person. The sensor is composed of a Passive Infrared Detector and Fresnel Lens. The main body contains the active electronics to measure movement and transmit any changes to a LoRaWAN network.

Inside, the sensor dual passive infrared detectors capture (through the Fresnel lens) the radiated heat of a human body with a field of view covering angles of 123° horizontal and 93° vertical.

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The sensor does not capture any visual data, nor can it detect any form of persona identifying features.

The payload a sensor sends consists out of 8 bytes:

• One byte for the status of the sensor

• One byte for the battery level

• One byte for the temperature of the PCB

• Two bytes for the time elapsed since last event trigger

• Two bytes for the total count of event triggers

 

The sensor will immediately send a message any time there is a transition from vacant to occupied state or vice-versa. Additionally, the sensor will send a message every 10 minutes while in the occupied state and every 1 hour while in the vacant state.

 

Depending on the location that needs to be monitored, the sensor will be placed in different ways:

• For a work space or desk a sensor will be placed with double sided adhesive tape to the bottom side of the table.

• For a meeting room or small closed off work places the sensor will be placed with double sided adhesive tape to the wall near the ceiling.

 

LED will confirm Join Accept, which confirms a successful activation of the device on the sensor platform:

 

The sensors used are FCC, IC, and CE certified. They are compliant with ROHS and REACH.

FCC ID: 2AMUGTBSP100

IC: 22980-TBSP100

Why do some Spacewell Motion (PIR) sensors have a cap?

As you can imagine, we want the sensors to be triggered where it makes sense:

• in meeting rooms, we want to track as much of the room as possible. Imagine someone standing in a corner to make a phone call: the room is occupied, because someone is using that room, so we want the sensor to pick up on any movement to reflect “state: occupied” in the data

• under desks, we want to track the occupancy of the chair in front of the sensor. We don’t want to track people on neighboring chairs when they’re stretching their legs, or people walking by in the hallway behind the desk. To achieve this, we did a lot of tests and ended up with a cap that restricts the “viewing angle” of the sensor.

Visit Quality Assurance Occupancy and Utilization Sensor to understand how meticulous we are in our checks at the end of a project, to make sure that false-positives (the sensor being triggered but the chair at the desk is not occupied) or false-negatives (the sensor not picking up on the movement of the intended person) are kept to a minimum.

How is Motion sensor data reflected in Workplace Live Views?

Upon a Motion sensor being triggered, the signal goes up immediately, but only goes down after a few minutes:

• So as soon as occupancy is detected, a signal is send to the Workplace Platform, which will reflect in Workplace touchpoints' floorplans in near-real time: the location occupancy color goes from GREEN to RED almost instantly, but goes from RED to GREEN based on a fixed timer which cannot be shorter than 10 minutes.

• This means that human motion can only trigger the sensor to go from '0' to '1' , and not the other way around.

Once the sensor goes up (meaning “presence detected”), it can't change its state faster than 10 minutes, which is why the default decay on the red icon lasts 15 minutes. The decay is actually nothing more than a clock counting down until the next refresh, regardless of the presence during that window.

In other words: The reason for using this decay is to indicate that the probability that the location is still occupied is lowering.

Decay Configuration options

Perhaps you would want to indicate in Workplace Live Occupancy View that if a motion sensor has been triggered, the location is occupied for at least 2 more hours, so that colleagues and guests can go to lunch or drop by a meeting without having to fear that someone is clearing out their workplace*

? But at the same time you want to indicate that a meeting room has freed up as quickly as possible, so that it turns green (“available”/”not occupied”) and people can recognize this at a glance?

The Workplace back-end Studio configuration options have you covered: per room category, both the icon and the decay timer can be modified

* (only possible if the locations have been created as rooms in IWMS, as this feature only lists room categories)

How does this reflect in Workplace Dashboards?

Even if you want to show your colleagues in Workplace Live Occupancy View that a desk is “occupied” while you’re actually jumping from meeting to meeting in other rooms, the data will show that the desk was only really occupied for some brief moments. Per default, data aggregation happens per 15 minutes.

Following page provides more insight into how data is saved into the Workplace IoT Platform: https://spacewell.atlassian.net/wiki/spaces/WM/pages/492237

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