Nordic Semiconductor, the manufacturer of the System on a Chip (SoC) in many beacons, has published the latest online issue of Wireless Quarter Magazine. It showcases the many uses of Nordic SoCs.
The latest issue of the magazine highlights the increasing use of IoT. Nordic Semiconductor has been known for enabling Bluetooth and cellular solutions and with their recent acquisition of Imagination Technologies this now extends to WiFi.
The magazine covers many usecases including:
Bluetooth connected prosthetics
CHIP smart home
Smart health
There’s also an informative article exploring the usefulness of patents.
Cordova, previously called PhoneGap, is a mobile cross platform development tool that uses web pages and Javascript.
Don Coleman of Chariot Solutions maintains the open source cordova-plugin-ble-central custom plugin (blue area in above diagram) that provides a Bluetooth API for scanning, connecting to service characteristics, reading and writing values and characteristic change notification. Examples are provided.
The recent updates provide support for new permissions and API changes in Android 10+. It’s great to see the plugin updated because the problem with many tools and libraries is that they rarely keep up to date with changes in the underlying iOS and Android APIs.
The solution processes the received signal strength (RSSI) to determine anomaly rates of beacons and hence filter out abnormal signals. This helps to overcome the problems of unreliable signal strength in indoor locations due to reflections and obstacles.
The system achieves an average positioning error of 1.5m.
When people think about IoT sensors they tend to envisage, for experimenters, discrete electronic components connected to single board computers (SBC) or for industrial, custom sensors connected to microcontrollers.
The problem for experimenters is the solution is fragile and needs to be evolved into a custom electronic design before it can be used in production. For industrial solutions, they tend to be proprietary, require deeply invasive installation and very expensive.
Example IoT Dashboard Using Sensor Beacons
Sensor beacons provide an easy, ready-made solution that have the following advantages:
They provide a solution that’s equally as good for experimentation as it is for the final production
They can be placed in remote areas where there’s no power or network connectivity.
They can be self powered and last for 5+ years.
They can detect quantities such as position, movement, temperature, humidity, air pressure, light and magnetism (hall effect), proximity and heart rate.
They can be easily attached to existing to exiting assets to make them IoT enabled.
Being Bluetooth standards-based, the sensor data can be easily read via gateways, smartphone apps or single board computers and sent on, as necessary, to servers.
Bluetooth-WiFi Gateway
Using beacons sensors in this way also provides for the ‘big data’ required for AI machine learning.
The Bluetooth SIG has a new Developer Study Guide by Martin Woolley showing how to create a Bluetooth gateway. Gateways are the bridge between Bluetooth devices and the Internet.
The developer study guide explains GAP, GATT, broadcasting devices and develops an architecture for capturing Bluetooth data:
It’s implemented using Python on a Raspberry Pi 4:
The guide has a section on Buy vs Build where it’s explained that, depending on your skills and budget, you might consider buying a commercial gateway.
Raspberry Pi based solutions aren’t always reliable in the long term because the micro SD card eventually fails. Most gateways also send (push) data to your server rather than an application having to query (pull) the gateway as is the case with the example in the study guide.
FedEx has started to use Bluetooth sensor beacons to track packages. The SenseAware ID device provides more frequent location updates and temperature, humidity and vibration data for premium packages.
SenseAware ID is part of the FedEx SenseAware offering that has previously used devices with cellular technologies. SenseAware ID devices are instead detected by gateways at UPS sites.
There’s a new app for iOS called Stepping In & Out that uses iBeacons to remind you when you move into or out of an area containing a beacon.
The source code is available on GitHub. It provides an example how to create an app using Swift that triggers when going into and out of zones. This can also be used for commercially oriented applications.
The W2 advertises iBeacon, Eddystone and acceleration. It’s rechargeable via USB and can be configured to provide continuous, button triggered or motion triggered advertising.
The acceleration sensor is the STMicroelectronics LIS3DH that’s configurable for scales of up to ±2g/±4g/±8g/±16g.
Bluetooth tags/beacons detect the position of people and assets. Software maps jobs, valuable tools, parts, sub-assemblies and people onto your floor plans or maps.
The main uses are:
Searching. Knowing the location of something such as a piece of equipment, parts, stock, pallets, a job or person without ringing round. Locating expensive, shared, equipment so fewer spare assets are required to cover an area.
Security. Alerting when people or assets enter or leave an area.
Protection. Detecting quantities such as temperature and humidity for sensitive items that can spoil.
Process Control. Knowing where things have been. Knowing what happened at a particular location. Knowing when measured values exceeded their expected range.
Bluetooth LE is particularly suitable because it is:
Real Time. Better than barcode scans and NFC tags where the data is only as up to date as the last successful manual scan.
Compatible. Bluetooth LE works with existing devices such as smartphones, tablets, laptops and desktops.
Inexpensive. Commodity hardware is more affordable than non-standard technologies such as ultra wideband (UWB).
The end result is reduced downtime, less time re-ordering or re-making things that have been lost, optimum productivity and better use of skilled staff doing their job rather than searching for assets and people.
Flutter is Google’s UI toolkit for building native applications for mobile, web, and desktop from a single codebase. There are plugins that add functionality to Flutter. One such plugin is the beacon_plugin that makes it easier to scan and range iBeacons on iOS and Android. The plugin is open source on GitHub.
