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.
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.
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.
Occasionally, our customers ask for things we didn’t expect, contradictory requirements or requests that require unusual solutions. Here are some examples:
We were once asked for the beacons we considered to be least attractive. The idea was that they were going to be rolled out into a busy public space and would otherwise easily get spotted and stolen. Small, black beacons turned out to be the solution.
We are often asked what’s the best beacon for Android (or iOS) development. There actually isn’t a best one as they all advertise similar data. Instead, the best beacons are those that can be easily turned on and off to test triggering.
Some people ask for mains powered beacons. We aren’t aware such products exist. Instead look at USB beacons that can be powered by USB mains adapters.
It’s often the case people want the longest possible battery life and the smallest possible beacon. These two factors are mutually exclusive because a large battery is required for a long battery life. It’s necessary to either decide which is the most important or compromise on both factors.
We are sometimes asked to recommend beacons that have the best iOS and/or Android SDK. In these cases the best SDK is no SDK.
These examples demonstrate what’s right for one project isn’t necessarily right for others. This is why we stock the widest beacon range in the World.
You might wonder whether USB beacons can be used to enable desktops/laptops or any USB device to receive beacon transmissions.
USB beacons don’t work this way and only use the USB connection for power. A few such as the Minew U1 have UART USB serial support that can be used to control the beacon but it still doesn’t detect beacons. It beacon only sends and doesn’t receive.
What you need is a ‘Sniffer’ such as the ABSniffer 528. It scans for Bluetooth devices and sends the data via USB to the device powering it.
Alternatively, look for a standard Bluetooth dongle that that supports Bluetooth Low Energy (LE) and an associated programming API for ESP32, Raspberry Pi, Windows or Linux.