iBeacon, Eddystone, Bluetooth, IoT sensor beacons, apps, platforms
We have recently come across Beacon Server, a useful application for Raspberry Pi 3 and OS X, by Yannick Weiss in Switzerland, that detects beacons and calls webhooks, for example IFTTT when a beacon enters or leaves the area. It’s controlled via a web interface:
There’s recent research by Beakcheol Jang, Hyunjung Kim and Jong Wook Ki of Sangmyung University, S Korea on An Accurate Indoor Positioning Algorithm Using Sensors and Crowdsourced Landmarks.
The paper describes how to obtain more accurate heading direction and user coordinates by combining smartphone sensors and iBeacons as landmarks.
There’s a video on Facebook where the Spencer Matthews from BBC’s Watchdog programme looks into beacons:
We were contacted by a researcher from BBC Watchdog as they wanted to understand the mechanism and were initially confused as to whether the devices in stores were receiving phone Bluetooth signals or the other way around, phones receiving Bluetooth signals.
What the video doesn’t say is apps are needed to see the beacons. In the case of Facebook this will be Facebook app. You can turn off Bluetooth for that app if you don’t want to be tracked. However, as the video explains, Bluetooth is only one mechanism. WiFi, GPS and cell tower data can also be used to determine location.
Getting back to beacons, Google has an under-promoted similar mechanism ‘Project Beacon’ tied to Adwords where you can work out if an ad caused a store visit.
As there’s no official web site or information, it’s unclear if ‘Project Beacon’ is still active.
The BBC Watchdog video shows how many consumers see such adverts as intrusive and creepy. As previously with Eddysone URL, marketers are being too blunt, alienating consumers and it’s a turn-off. Instead they need to provide useful information and tools, not adverts, then convert the consumer to a sale. Marketers need to put in place marketing that causes the consumer to say, “That’s cool, I must tell my friends” rather than “That’s creepy”.
We have a new range of Sato beacons in stock:
Most, except the sensor beacons, are waterproof to IP67. All the beacons can be configured to advertise multiple channels at the same time including iBeacon, Eddystone UID, Eddystone URL, Eddystone TLM, sensor (where available), acceleration (where available) and device info.
Sato beacons use the button in an innovative way. Instead of going OFF, the button long press is detected for SOS type scenarios. The beacon is instead turned off using the configuration app or programatically via your custom app.
Scapy is a useful command line Python program, that works on Linux, that enables the user to send, sniff and dissect network packets, including Bluetooth LE. It can be used for testing, development and security testing.
Scapy allows:
If you are considering developing Bluetooth LE on Android, you should take a look at Stuart Kent’s Android Bluetooth Low Energy Resources on GitHub. He provides lots of links to introductions, videos, libraries, guides, questions on Stack Overflow and example app source code.
If you need more information take a look at the Android section of the BluetoothLE Wiki. If you need to rely on background processing read Don’t Kill My App.
If you have upgraded to Android 10 then you will find you are asked whether particular apps, especially those using maps or Bluetooth, can use Location permission (all the time, only while using the app or Deny). Something like:
You will find that this screen appears, for each app using Location, at a seemingly random time. Why is this? Why do apps you haven’t just started suddenly ask for the permission? What are they doing? How should you answer?
The change of Android location permissions to include ‘only while using the app’ is part of Android 10. For app architectural purposes, some apps get location or Bluetooth scan in an Android Service that runs in background. This Service can be started and stopped by the Android OS according to whether the OS needs resources and also when an app is upgraded. The starting of the Service might cause it to get location or do an initial Bluetooth scan, as part of startup, even though the app isn’t going to use this information. These things used to be transparent but now have the knock on affect of causing the OS to ask for the first-time permission seemingly at a random time.
If, for example in the above BBC Weather app, you need the app to show the latest weather for a location on a widget or otherwise use location-related data in background then select ‘Allow all the time’. Otherwise select ‘Allow only while using the app’. Beware of selecting ‘Deny’ as it’s likely it might cause the app to malfunction in some way.
Our empirical experiences are that Android 10 background restrictions do actually noticeably improve battery life, unlike previous Android ‘Doze’ and App Standby restrictions that seemed to create pain and no gain.
There’s novel recent research on City Marathon Active Timing System Using Bluetooth Low Energy Technology by Chun-I Sun, Jung-Tang Huang, Shih-Chi Weng and Meng-Fan Chien of Taiwan.
The authors discuss the use of beacons vs RFID and create a system using Received Signal Strength Indicator RSSI and gateways connected to detector mats:
Beacons are carried by athletes. The gateways sync their times via NTP and send data up to a MongoDB database:
An accuracy of ±156 ms was achieved which compares well to the nearest second used to generally record times and resolution accuracy of 0.1s for commercial transponder timing systems.
Nordic, the manufacturer of the System on a Chip (SoC) in many beacons, has the latest issue of Wireless Quarter Magazine. It showcases the many uses of Nordic SoCs.
News from the world of beacons and Bluetooth LE includes:
There’s recent research by Gabriele Salvatore de Blasi, José Carlos Rodríguez-Rodríguez, Carmelo R. García and Alexis Quesada-Arencibia of University of Las Palmas de Gran Canaria, Spain on Beacon-Related Parameters of Bluetooth Low Energy: Development of a Semi-Automatic System to Study Their Impact on Indoor Positioning Systems.
The paper starts by giving an overview of fingerprinting. It explains how fingerprinting is time-consuming and labour-intensive. Fingerprinting is affected by:
“Reflection, refraction, path loss, large fluctuations, multipath fading, non-line-of-sight (NLOS) conditions”
A problem is that some environment-related factors change over time, such as changes in hardware/furniture, the presence of people and ambient humidity conditions meaning that fingerprinting isn’t a one-off activity.
The researchers conclude that the highest transmission power (+4 dBm) produces the best location accuracy. However, this uses a lot of battery power. Use of the lowest power (−20 dBm) only worsened the accuracy by 11.8%. Similarly, lowering the density of the beacons by around 50%, the error increase was only about 9.2%. Increasing the advertising interval didn’t have a significant impact on the accuracy.
The affect of beacon orientation was assessed and vertical orientation was found to be best. As expected, introducing a slight electrical noise during the positioning phase did not significantly affect accuracy.
Read about Locating with Beacons