Laird CONNECTIVITY BT710 Sentrius Tracing Sensor User Guide
- June 5, 2024
- Laird CONNECTIVITY
Table of Contents
Laird CONNECTIVITY BT710 Sentrius Tracing Sensor
ABOUT THIS GUIDE
This document provides a comprehensive guide on how to configure the Sentrius™ BT710 Tracker functionality, including Bluetooth parameters, alert parameters, and general use for proximity sensing applications
INTRODUCTION
Product overview
The Sentrius™ BT710 Tracker or “tag” is a battery-powered, Bluetooth v5 integrated sensing and proximity tracking platform enabling tag-to-tag proximity sensing and logging along with tag-gateway communication for log upload. It contains several local alarm peripherals including four bright red LEDs, an RGB LED, an audible speaker, and a vibration motor. For applications where proximity sensing is desired with local alarm indication, the BT710 offers several user-configurable options to suit the use case. The BT710 is powered by Laird Connectivity’s field-proven BL653 BLE module that integrates Nordic Semiconductor’s nRF52833 SoC silicon.
- Clasp
- Status LED
- Speaker
- Alarm LEDs
- Pushbutton
- Magnetic Switch
Note: Laird Connectivity has a comprehensive staff of design services engineers available to help customize the tracker. Please contact your local Laird Connectivity sales representative for more details.
Specifications
See the BT710 product brief for detailed specifications. It’s available
from BT710 series product page or from the following link:
https://www.lairdconnect.com/documentation/product-brief-bt7x0-tracker
DEVICE OPERATION
Activating the Tracker
The Sentrius™ BT710 is shipped with the battery installed and operating in a
low power state called Shipment Mode. When it arrives from the factory, the
tracker is in shipment mode. To wake the device, press the pushbutton for five
seconds until the alarm LEDs turn on and a speaker tone is emitted (startup
sequence). This puts the tracker into Active mode. The tracker blinks the
status LED yellow waiting for its internal clock to be set, either by the
BT710 mobile app or a nearby gateway. If a gateway is not available, connect
the mobile app to automatically set the internal clock. Once in Active mode
with its clock set, the BT710 scans for compatible nearby trackers and
transmits BLE advertisements for other trackers to sense. In Active mode, the
BT710 tracker can be configured using the associated Laird Connectivity BT710
mobile application. The default configuration sets the tracker to periodically
scan for and log other trackers. Additional parameters include BLE
advertising interval, RSSI sense threshold, proximity alarm timers, and alarm
indicator styles. There are two low power modes: Non-Active and Power-Save.
The tracker automatically enters these modes based on motion detection to
extend battery life. User-configurable parameters control timing for this
feature. Separate BLE scanning parameters can be set for each operating mode
to scan less frequently in Non-Active mode and Power-Save mode
Figure 2 – Operating modes of the BT710 tracker
Press and hold the pushbutton for three seconds to perform a battery check. The BT710 lights up a number of its red alarm
- LEDs to indicate approximate voltage level of the battery.
- 4 LEDs on: 75-100% battery life remaining
- 3 LEDs on: 50-75% battery life remaining
- 2 LEDs on: 25-50% battery life remaining
- 1 LED on: 0-25% battery life remaining
When the BT710 senses a battery below the low battery threshold, it alternates a small beep sequence and blinks the status LED orange every 30 seconds as a reminder to change the battery
Factory Reset
If the button is held for more than 10 seconds, the status LED begins to
rapidly blink yellow. Releasing the button performs a factory reset. A factory
reset erases all logs and resets all parameters to defaults. The BT710 goes
through a reset cycle when
finished and emits the startup sequence LED pattern and beeps, followed by
entry into active mode.
Replacing Batteries
The battery is a 3-volt lithium of CR2477 type.
Note: The battery door cover is underneath the clasp on the backside of
the tracker. A coin may be used to aid in removal.
Active Mode Operation
Figure 3 – BLE operations in Active mode
When in Active mode, the tracker sequences through a series of BLE operations
continuously including Scan, Advertise, and Connected. The Scan Interval
parameter determines how much time passes between scan events, at which point
the tracker
awakes from sleep and performs a BLE scan (discovery of other trackers) for a
number of seconds defined by the Scan Duration parameter. When not connected,
the tracker advertises (transmits) data for other trackers to receive when
scanning. The rate of transmit events when performing the Advertise operation
is determined by the Ad Interval parameter. The advertisement data contains
identifiers to help filter out non-tracker devices, including device ID, TX
power, and other
status information. Flags in the advertisement can be used by gateway devices
to determine when a tracker has log data ready for download.
LED Patterns
Pre-Production Hardware
The pre-production tracker hardware provides a multi-color status LED for
detailed operating behavior to the user. The following table (Table 1)
describes the LED patterns used to indicate status. Note the blue LED
illuminates very weakly as
battery level drops
Table 1: Pre-production tracker hardware LEDs
Production Hardware
The production tracker hardware uses a red/green status LED to indicate
operating behavior to the user. The following table (Table 2) describes the
LED patterns used to indicate status.
Table 2: Production hardware LEDs
Alarm Styles
Several indicator styles are available providing control over how alarm
LEDs, audible tones, and vibration motor feedback are activated when an alarm
is triggered. These styles are configurable using the Alarms tab of the BT710
mobile application.
Indicator styles may be selected independently for Alarm 1 and Alarm 2
conditions. The following table (Table 3) describes the styles available for
each alarm indicator.
Table 3: Alarm indicator styles
care and Maintenance
The tracker can be cleaned with a mild, non-abrasive detergent. The tracker
is not IP-rated/waterproof, so do not immerse it in water or cleaning fluids.
The tracker does not require any calibration.
TRACKER ARCHITECTURE
The Sentrius™ BT710 advertises an identifying beacon used by other nearby BT710 compatible Bluetooth tracking devices and gateways to log proximity to the tracker. This advertisement includes information such as a user- configurable device identifier, a hardware identifier, and current status of the Bluetooth tracking device. You can configure a tracker using a Bluetooth connection and the Laird Connectivity ‘Sentrius™ BT710 – Bluetooth Tracker mobile application.
Advertisements
The following tables describe the data available in the advertisements of the BT710 tracker. Once a tracker is configured, it is possible for a mobile app or gateway to connect to the Bluetooth tracking device for configuration of parameters and/or data log download. The Bluetooth tracking device can be configured to transmit with an output power of -20 to +8 dBm.
lM PHY
Table 4: 1M PHY
lM PHY Scan Response
Table 5: 1M PHY scan response
Ad Record Types
Table 6: Advertisement record types
Flags
The flags are a bitmask of the current state of the tracker.
Table 7: Flags
Tracker Configuration
The tracker has several parameters that can be used to tailor it for each use
case. The table below lists the common parameters that can be adjusted by the
user based on the use case the tracker is being applied. These parameters can
be updated using the BT710 mobile application.
Parameter Selection Considerations
The parameters provide flexibility in configuration of timing and operation of the tracker for different use cases. For example, a fixed location asset tracker may be suited to scanning less often than a mobile tracker. The configuration parameters affect how often the tracker operates in each mode and therefore has a direct impact on responsiveness/latency of the log entries and battery life of the device. These parameters must be considered carefully for the log data to serve the purpose of a specific tracking application. The highest power usage occurs during the time the tracker is scanning/discovering other trackers. In this mode, the device is both transmitting its BLE advertisements and has the radio receiver turned on to discover nearby trackers for logging. The defaults target use cases where batteries are changed about once a month. If more time is necessary, the scan interval can be increased (scan less frequently), the scan duration can be decreased (scan for a shorter time period), or the advertising interval can be adjusted to keep the radio in sleep mode more often, thus extending useful battery life. TX power is also a consideration as higher power settings reduce battery life.
Note:
Scan interval, scan duration, and ad interval can be set separately for
Active mode, Non-Active mode, and Power- Save mode. By increasing the scan
interval and reducing the scan duration and ad interval during Non-Active mode
and Power-Save mode, the tracker can conserve battery life when motion is not
detected. For best power savings, set Power-Save mode scan duration to a value
of zero to keep from scanning altogether when the tracker has been idle (no
motion) for an extended period.
Firmware Updates
The BT710 tracker supports over-the-air (OTA) firmware updates when paired with an appropriate Laird Connectivity mobile application or gateway product. The process uses a standard DFU mechanism that can be incorporated into customer apps/products for compatibility.
Proximity Alarms
The tracker implements two programmable alarms that can be used to trigger
local audio, visual, and haptic indicators when a remote tracker is detected
for a configured amount of time. Each alarm has a parameter indicating the
number of seconds a
remote tracker must be detected before triggering the alarm indicators. Each
scan interval, the tracker determines which trackers are within proximity and
meet the configured RSSI threshold to begin recording. A counter increases
each time that same tracker is observed in a scan. Once [the number of scan
intervals a tracker is detected] x [Scan Interval parameter] is equal or
greater than the configured alarm time, the alarm indicators are triggered for
each subsequent scan that tracker is detected until the configured contact
period expires. The following diagram (Figure 4) shows the proximity alarm
timeline given default parameter values.
Figure 4 – Proximity alarm timeline
As a tracker detects other remote trackers (“remotes”) in a BLE scan, each
remote enters into a RAM-based discovery database in order to track the number
of scan intervals each is seen for alarming purposes. Each remote is on its
own timeline
from the perspective of the sensing tracker. Each time a remote is detected in
a BLE scan, a count of seconds is added to that remote’s total detection time
in the database. This number of seconds is equal to the Active Scan Interval
parameter. If a remote is not detected in a scan, the total detection time in
its database entry is not incremented for that scan interval. For example,
with default parameters, each scan interval a remote is detected adds 30
seconds to its total detection time in the database. After any remote is
detected in enough scans such that the total detection time crosses a
configured alarm threshold, the configured alarm indicators are triggered to
alert the user. The alarm continues to trigger each scan interval until no
remotes having total detection time longer than the alarm time setting are
within range. Once “Contact Period” seconds passes since the first time a
remote is detected, its total detection time is reset to zero in the database,
starting a new proximity alarm timeline for that device once it is detected in
a future scan.
Data Logging
The BT710 tracker is designed to log data from other compatible tracker
devices it observes during its BLE scan operations. The following diagram
(Figure 5) shows the data logging timeline and how various parameters affect
each logging phase
Figure 5 – Data logging timeline
As a tracker detects remote trackers (“remotes”) in each BLE scan, the
discovery database is updated and the remote steps through three phases
throughout a single Contact Period.
- Discovery Phase – Remote trackers are tracked in a RAM-only discovery database for each scan they are detected. Once the total detection time is greater than the configured Discovery Duration, the records for the remote are committed to a Flash-based log and the remote enters tracking phase. If a remote is only detected fewer scan intervals than the configured Discovery Duration within a given contact period, they are cleared and not logged to Flash. This is useful for situations where trackers are in proximity for very brief periods of time and do not warrant storage to the Flash-based log.
- Tracking Phase – Remote trackers in the tracking phase get an additional record in the Flash-based log for every scan interval they are detected, up to the maximum records that can be recorded for the duration of the tracking phase (set by the Tracking Duration parameter).
- Untracked Phase – If a remote tracker has been detected for the entirety of the Tracking Phase, no more records are made for that remote until the Contact Period expires. This way, a single remote only takes up a maximum number of Flash log records are determined by the Tracking Duration each Contact Period, allowing the remaining Flash space to be used for detection and logging of other remote devices during that Contact Period.
Data Log Entries
The BT710 tracker can store up to 350 log entries within a 24-hour contact period. Each log entry can store 15 records for a remote tracker, one per scan interval. The number of unique remote trackers that can be logged is a function of the Scan Interval and Tracking Period parameters. For example, with tracking period of 15 minutes, up to 350 unique remote devices can be tracked if scan interval is set to 30 seconds. The following data is logged from the remote tracker’s advertisement data:
Overview
The Sentrius™ BT710 mobile application allows a user to configure tracker parameters and update firmware.
Using the Sentrius”·’ BT710 Mobile App
To use the Sentrius™ BT710 mobile application, follow these steps:
- From the applicable app store (Apple or Android) search for and install the Sentrius™ BT710 mobile application on your mobile device.
- To connect to the BT710 tracker, make sure it is in Active mode.
- Tap FIND BT7 DEVICE to discover the tracker(s) within range of the mobile device.
- Select the tracker to connect. Tracker names start with BT710 and end with the last four digits of the BLE ID as printed on the back of the Bluetooth tracking device. Once connected, the app displays the current parameter values configured for the tracker. Parameters are grouped using tabs near the bottom of the page.
FREQUENTLY ASKED QUESTIONS
Please refer to the support FAQs online which can be found here:- https://www.lairdconnect.com/support/faqs
ADDITIONAL ASSIST /\NCE
Please contact your local sales representative or our support team for further
assistance:
Laird Connectivity
Support Centre:
https://www.lairdconnect.com/resources/support
Email: wireless.support@lairdconnect.com
Phone: Americas: +1-800-492-2320
Europe: +44-1628-858-940
Hong Kong: +852 2923 0610
Web: https://www.lairdconnect.com/iot-devices/iot-sensors/sentrius-bt7x0
-tracker-multi-sensor
Copyright 2020 Laird Connectivity. All Rights Reserved. Any information furnished by Laird Connectivity and its agents is believed to be accurate and reliable. All specifications are subject to change without notice. Responsibility for the use and application of Laird Connectivity materials or products rests with the end user since Laird Connectivity and its agents cannot be aware of all potential uses. Laird Connectivity makes no warranties as to non-infringement nor as to the fitness, merchantability, or sustainability of any Laird Connectivity materials or products for any specific or general uses. Laird Connectivity or any of its affiliates or agents shall not be liable for incidental or consequential damages of any kind. All Laird Connectivity products are sold pursuant to the Laird Connectivity Terms and Conditions of Sale in effect from time to time, a copy of which will be furnished upon request. Other marks may be the property of third parties. Nothing herein provides a license under any Laird Connectivity or any third-party intellectual property right.
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