BT510 Bluetooth 5 Long Range IP67 Multi-Sensor

There's a Zephyr RTOS Discord channel.  This is a great place to ask questions and have them answered by the engineers who wrote the software.  There's even a channel for HL7800!

Project Zephyr Discord

BT510 has 1MB internal flash memory. 

These instructions are intended for Linux or Macintosh OS. They may work using WSL, Cigwin, or other bash style terminals in Windows although this is untested. 

It may be desired to communicate with a device attached to the USB-SWD without terminal emulation, I.E. Picocom, Screen, Putty.  This can be useful for writing bash scripts, or if you're using Zephyr's "west flash" and would like a quick way to check your output. 

1. Verify you have the program "stty" available using the command "which stty", if this does not return a value you will need to install it.  Fortunately "stty" generally comes standard with Linux and MacOS.  
2. Identify your serial device.  This can be done using the command "dmesg -w" then connecting the USB-SWD.  You will see output like this (In Linux).

3. (Optional) Assign the device name to a variable, for example "DEVICE=/dev/ttyACM0".
4. Configure "stty" to talk with the device "stty -F $DEVICE 115200 -echo -echoe -echok"
5. To see output from the device execute "cat $DEVICE &".  This will send serial communication from the device to Linux's standard output.  The "&" is to run this program in the background.
6. Now press the reset button on the USB-SWD, you should see the output from your device.  In this example the Zephyr "Hello World" example has been flashed to a BT510. 

7. (Optional) if you would like to send commands back to the device you can use "echo" or add an argument to your shell, "foo() { echo -n -e "$1\r" > $DEVICE; }".  Now commands can be issued directly from the command line, for example "foo "my_command"" will send the string "my_command" to the device. 

As part of the default BT510 firmware developed by Laird Connectivity, the accelerometer data is pretty binary:

• Movement detected.
• No movement detected.

The BT510 motion detection is done by comparing accelerometer data against an arbitrary threshold adjusted by a slider into the Sentrius BT510 phone application.

Any overshoot of acceleration detected will trigger the event "Movement" which then will be advertised afterwards.

The default BT510 accelerometer use-case is mainly targeted to motion detection of an asset during a logistics supply chain. Customers can set the above threshold from 1 to 99 to adapt motion detection sensibility according to their needs.

If customers decide to develop their own firmware, they can have access to further data like acceleration value and orientation.
However, the ST LIS2DH sensor embedded into the BT510 doesn't include vibration frequency application:

Hence it makes the BT510 not really suited for vibration frequency measurement applications.

The BT510 uses a SiLabs SI7055 I²C temperature sensor : https://www.silabs.com/sensors/temperature/si705x/device.si7055

You'll find its calibration certificate here : https://www.silabs.com/documents/public/miscellaneous/si70xx-calibration-certificate.pdf

We do have a dedicated Github page page that exposes Python examples code which undertake common operations between a BT510 and a BL654 loaded with smartBASIC AT Commands Interface.

It especially includes :

• Sensor configuration
• Analysing advertisements
• Reading and decoding BT510 event logs
• ... and many more!

These codes can be easily leveraged for any real world applications that would include BT510 mated with the IG60-BL654 or any other custom gateways.

You can find more information on the following page : https://github.com/LairdCP/BT510-Python

Technically any magnet with sufficient field strength and proper field orientation can be used.
The magnet sensor used in the BT510 is a magnetoresistive sensor and hence the sensitive axis is in the sensor plane (other than for hall sensors where the sensitive axis is perpendicular to the sensor plane). Below picture indicates the sensitive axis. The sensor is NOT sensitive to the direction of the field!



More information about sensitivity and orientation recommendations from the sensor chip perspective is in the SM351LT data sheet. The below picture summarizes the most important aspects. It also shows the orientation of the sensor chip relative to the BT510 enclosure. The magnet coming with the BT510 is a rod-style magnet with axial magnetization and hence the field lines go from the short sides (top/bottom) of the magnet (more or less parallel) along the long sides of the magnet like indicated in the “magnet movement” section of the picture. This orientation ensures the field lines penetrating the sensor chip mainly along its sensitive axis. One can also see that rotating the magnet by 90° would lead to the field lines penetrating the sensor chip perpendicular to the sensitive axis and hence not generate any signal.



When selecting a different magnet than the standard BT510 magnet both field strength and orientation needs to be taken into account. A magnet with higher field strength can cover a larger operating distance to trigger the magnet switch. 

There exist a lot of standard round magnets on the market often used to stick/fix something onto metal surfaces and hence the magnetization is not critical and works for any magnetization type (like axial, vertical, diametrical…). However, often the magnetization type is not even specified for a particular magnet and cheap ones (like used for white boards) sometimes even have several magnetic poles in parallel over the area of the magnet. This actually helps for the common use-case of sticking well to metal surfaces but makes them quite unusable for reliably and reproducibly triggering a sensor chip.

How to best orientate your round magnet to get stable sensor near/far readings would depend on how the magnet is being magnetized and how the magnetic field lines would penetrate the sensor chip when applied. If the magnetization is unknown a magnetic field viewer (aka flux detector/viewer) can be used to "see" the magnetic poles and get the orientation of field lines.
 
The general advice would be to either use a rod-style magnet with axial magnetization in the above shown orientation or a round magnet with known magnetization type and then positioned in a way so that the field lines penetrate the sensor in its most sensitive axis. To ensure this, the magnetization of the magnet must be known before mounting.

Task 10 failed occurs when a firmware update fails. If you see this error please make sure you are using the latest version of the BT510 app and retry the firmware upgrade.

Yes, the BT510 Sentrius™ BT510 sensor is replaceable by removing the rear battery door cover.

The battery is a 3-volt lithium of CR2477 type.

The battery door cover has a gasket inside to keep out liquids.

The Sentrius™ BT510 is a Bluetooth 5 Low Energy multi-sensor and can last for months or years on its replaceable coin-cell battery. That battery life is dependent on lots of factors such as sleep time, ambient temperature, and more.

To estimate how long your BT510 application can go on a single battery, adjust the values at the BT510 battery life estimator

The Sentrius™ BT510 sensors range is dependent on a number of factors some of which are under user control.
You can configure a sensor using a Bluetooth connection and the Laird virtual serial port(vSP) service. The protocol sent over the virtual serial port is JSON-RPC version 2.This allows you to add new commands and features without changing the Bluetooth interface.
This includes being able to configure

• Tx power
• LE Coded (Long Range) PHY

More details are available via the BT510 user guide.

It is also possible to extend the range of the BT510 using the Laird BL654 Repeater/gateway smartbasic programs this allows the Laird BL654 module to function as a repeater or gateway for adverts from Laird’s BT510 sensors. It can also operate in AT mode where it can advertise, scan, connect, and offer GATT client and server capabilities. This application is controlled with the industry standard AT command protocol over a UART interface.

• BT510 Repeater Mode–The module listens for adverts from Laird’s BT510 sensors or other BT510 repeaters and rebroadcasts over the air so that a range extension can be facilitated. All other adverts are ignored.
• BT10 Gateway Mode–The module listens for adverts from Laird’s BT510 orBT510 Repeaters and sends them out in hex format over the UART interface so that a host can process them. It could forward to the cloud if it has the appropriate connectivity. All other adverts are ignored.
• Generic BLE Client/Server Mode–The module can be made to advertise, scan, connect, and pair. In addition, it can enable the creation of a GATT server table on-the-fly and, conversely can be a GATT client to interact with remote GATT servers.

More details are available via the BT510 Repeater/Gateway user guide.
The source code for all of these applications is hosted on our GitHub page:

The Sentrius™ BT510 advertises events. An event can be a temperature measurement, an alarm ,a battery measurement, a button press, a door opening/closing, or movement. The configuration of a sensor determines what kind of events it generates.

Access to accelerometer values is not possible but it is possible to configure the accelerometer sensitivity. You can configure a sensor using a Bluetooth connection and the Laird virtual serial port (VSP) service. The protocol sent over the virtual serial port is JSON-RPC version 2. This allows you to add new commands and features without changing the Bluetooth interface. The BT510 accelerometer creates a movement event.
More details can be found in the BT510 user guide.

Yes!

You can configure a sensor using a Bluetooth connection and the Laird virtual serial port(vSP) service. The protocol sent over the virtual serial port is JSON-RPC version 2. This allows you to add new commands and features without changing the Bluetooth interface.

This includes being able to change the PHY to LE coded for long range applications.
The Laird BT510 smartphone applications allows a user to select LE Coded PHY.
LE Coded PHY can also be selected from your own smartphone application using JSON over VSP BLE connections.
Details can be found in the BT510 user guide

Out of the box the BT510 is configured via a smartphone app but this does not allow a developer to reprogram the BT510. However the BT510 can be programmed by a developer using Zephyr in C. More details can be found at the following link.

The Zephyr OS is based on a small-footprint kernel designed for use on resource-constrained and embedded systems: from simple embedded environmental sensors and LED wearables to sophisticated embedded controllers, smart watches, and IoT wireless applications.

The BT510 sensor is configured using a smartphone via BLE out of the box. It is also possible for a developer to load their own C code onto the BT510 via a programming cable.

The BT510 board does not have an on-board J-Link debug IC as some nRF5x development boards, however, instructions from the Nordic nRF5x Segger J-Link; page also apply to this board, with the additional step of connecting an external debugger.

Laird Connectivity will provide the USB-SWD programming board that supports this connector layout, refer to the USB SWD Programmer product page

The following string should be sent over VSP, where 8 is 8dBm

{"jsonrpc": "2.0", "method": "set", "params": {"txPower": 8}, "id": 1}
Valid values include:
-40 dBm, -20 dBm, -16 dBm, -12 dBm,  -8 dBm, -4 dBm, 0 dBm, +2 dBm, +3 dBm,  +4 dBm, +5 dBm, +6 dBm, +7 dBm, +8 dBm

See the user guide for further details.

After factory defaulting the BT510 it enters shelf mode. Before configuring the BT510 sensor from the app you should press the button on the front of the sensor for 3 seconds to move it from shelf to active mode before configuration from the BT510 app.

Laird Connectivity is committed to the long-term supply of all its standard embedded wireless modules and packaged products. Laird Connectivity’s products are specifically designed to meet the needs of the industrial and medical markets, which typically require 7 – 10 years product lifecycle. Although Laird Connectivity can’t guarantee that a component used in our products will not be obsoleted and cannot be reasonably substituted, Laird Connectivity can assure customers we will continue to sell our product when we have customer demand and can obtain the necessary components to build our products.

View our full policy here.