BeaconZone Blog – Page 23 – iBeacon, Eddystone, Bluetooth, IoT sensor beacons, apps, platforms

Custom Bluetooth Beacons

While we stock a very large range of beacons, it’s occasionally the case that beacons needs to be customised to better suit the project. There are different types of customisation with corresponding complexity and cost. There are also different minimum quantities at which the different forms of customisation become financially viable.

The most basic customisation is setting of the settings at the factory at time of manufacture. This saves lots of time at rollout because each beacon doesn’t have to be configured using the smartphone app. If configured at the factory, beacons can still be subsequently updated if there’s a change of some sort.

Beacons with custom settings and labelled

The settings typically include setting the beacon id, power and advertising period. Labels are also usually attached to the beacons so they they can be visually identified. Configuration at the factory implies they are manufactured to order which typically takes 4-6 weeks depending on the factory and time of year. The minimum quantity is usually about 200 to 300 units. We also manually configure smaller quantities for clients but this is much more expensive per unit.

The next level of customisation is changing the colour of the case and/or branding the beacon with a logo. Again, the minimum quantity is usually of the order of 200 to 300 units.

Some customers need the case to be a specific size, shape or to be, for example, more rugged. It’s also possible to re-specify some of the inside components to improve ruggedness, particularly when beacons are to be used under vibration.

Custom cases are much more time consuming and can take 3-6 months. The beacon usually has to be re-certified that’s also time consuming and expensive. Case modifications are usually only financially viable for tens of thousands of beacons.

The final type of customisation is to have non-standard software. This might include new sensors or use existing sensors in innovative ways. This usually takes of the order of 3-6 months software development. Software can be flashed manually onto small numbers of devices but the software image is usually eventually sent to the factory for putting into the beacon at the time of manufacture. Because of the software development cost, this is usually only financially viable for tens of thousands of beacons.

For all customisations, it’s possible to have samples but the factory always needs payment upfront for the full shipment. For very large custom orders we can work on a consultancy basis. We use our skills and expertise to effectively communicate with suitable manufacturers and tie down your specification after which we hand over to you to purchase direct to save costs.

The Affect of the Number of Beacons on the Detection Time

We have been involved in a few projects where there have been 100s of Bluetooth beacons in one place at the same time as opposed to, the more normal, 10s at a time. We have found detection times to be significantly longer. Until now, we have found it difficult to quantify this behaviour.

We have found some research, funded by Samsung, on the Analysis of Latency Performance of Bluetooth Low Energy (BLE) Networks. The research contains lots of theoretical predictions backed up with experimental data that show how the time to detect varies with the number of scanners, number of advertisers, the scan window size, the advertisement period and the advertising interval:

The research concludes that when the number of Bluetooth devices increases, delays in device discovery show an exponential growth even when using multiple advertising channels and small frame sizes.

The authors say:

“We find that the inappropriate parameter settings considerably impair the efficiency of BLE devices, and the wide range of BLE parameters provides high flexibility for BLE devices to be customized for different applications.”

So what typical parameter settings might affect the detection time? What’s really going on? If you look at beacon advertising it transmits for about a millisecond every configurable advertising period (typically 100ms to 1 sec):

In simple terms, if two beacons happen to transmit on the same channel, at a similar time, then the transmissions will collide and receiving device will see corrupted data. The receiver will have to wait for its next scan to possibly see the beacon(s) and this increases the detection time. The chances of collision increase as the number of devices increase and decrease as the beacon advertising period increases.

Note that if two beacons collide and have the same advertising interval, it doesn’t mean they will collide next time. The advertising interval has a small amount of randomisation added to make this less likely to happen.

Beacons Help Find Lost Dementia Patients

The Jockey Club Centre for Positing Ageing in Hong Kong has been working with The Hong Kong University of Science and Technology and St James Settlement to create a system to aid the search for older people with dementia who get lost.

The solution works on the premise that people who get lost generally go to places where there are other people. A Bluetooth beacon-based device is detected by an app installed by 23,400 ‘dementia angels’. They receive an alert when someone is lost and are asked to turn on Bluetooth and location. When the lost person is detected the location is anonymously sent to a cloud server and then to the caregiver to aid with searching.

The beacon comes in several forms including suitable for putting into a wallet or attached to a walking stick. In 45 out of 131 lost episodes, the caregivers were able to use the technology to help search for their relatives with dementia.

87% of caregivers thought that the iBeacon was easy to carry for the people with dementia and 82% observed that their relatives with dementia were willing to carry the iBeacon. 79% of caregivers were satisfied with the durability of the iBeacon and 75% thought that the designated mobile app was easy to use. In addition, 74% of caregivers trusted data security. The overall programme satisfaction rate was 85%, revealing that they held a positive view of using this technology in their daily lives to prevent getting lost.
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Warning System for Home Monitoring

There’s new research into a home people tracking system to detect people who are isolated at home. The context is home isolation due to Covid but this could equally be used for people with limited mobility who need to stay indoors.

The idea is to use Bluetooth rather than visual, camera-based monitoring. Smart bracelets are used that can also monitor position, blood oxygen and heart rate.

The system can also send early warning signals to organisations or relatives through instant messaging software.

The system is implemented using ESP32 single board computers and a Raspberry Pi for data collection.

This uses MQTT, Node-Red and a database.

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Using AI Machine Learning to Improve Ranging Accuracy

There’s new research from Oregon State University, USA and Peking University, Beijing, China on A Machine Learning Approach to Improve Ranging Accuracy with AoA and RSSI.

Machine learning was used to determine the line-of-sight distance in a multipath (reflective) environment. Due to the multipath effect, acquired signals indoors have complex mathematical models. A machine learning Artificial Neural Networks (ANN) is the most efficient way to process these signals.

The system achieved accuracy where 75% of the errors were less than 0.1 m with a median error of 0.037 m and a mean error of 0.092 m. This reduced ranging errors to under 10cm. The researchers were able to achieve high-precision indoor ranging without the need for a wide signal bandwidth nor synchronisation. The system was also simple and low cost to deploy due to low complexity of the equipment.

How to Read the AnkhMaway Sensor Data?

Since we have been selling the AKMW-iB003N-SHT and AKMW-iB004N PLUS SHT we have been getting a few questions regarding accessing the temperature and humidity data.

You should first read the manufacturer’s SHT20 User Guide (username and password supplied with your beacon).

If you are connecting via GATT to read the sensor data then you will need to set the beacon to be always connectable. The way to do this is (for some strange reason) only shown in the iB001M user guide:

So if you wish to transmit iBeacon and remain connectable, set the value to 0x82. Note that if you subsequently set the beacon ‘on’ or ‘off’ in the ‘simple’ configuration screen, accessed via the spanner icon (Android) or Configure option (on iOS), then this will overwrite your set value.

However, you might instead consider reading the sensor data from the advertising data which a) is much easier to program and b) uses much less beacon battery power and c) allows multiple apps to see the data at the same time.

There’s also an iOS example app in the BeaconZone AnkhMaway technical area.

Getting the AnkhMaway Battery Level from Advertising Data

One of the great things about AnkhMaway beacons is that they provide the battery level in the advertising data. This allows you to view or easily programmatically determine the battery level without connecting. For example, here’s the output from the Android iBeaconDetector app:

The last two useful hex characters of the advertising data, ‘5E’ in this case, gives the level out of 100. You can use an online Hex to decimal converter to see the value in decimal that’s 94% in this case.

Note that the battery level in the advertising data is only present for recent firmware versions which might not be the case if you haven’t purchased the beacons from BeaconZone.

Beacons for Immersive Experiences

We are seeing beacons increasingly being used in immersive experiences in theatre productions, events, museums, galleries, theme parks and with augmented reality (AR). Beacons provide physical location cues for tech-driven immersive experiences.

Beacons have a variety of uses in immersive experiences. They cause things to happen based on the location of a person or things or their mutual proximity. They provide a way of counting how many people or things are in an area. Some beacons have buttons that allow for human interaction. There are also sensor beacons that expand what’s possible through the detection of temperature, light, proximity, physical open/closed, movement and fall detection. Beacons replace what might usually have been done manually thus saving costs, sometimes implementing scenarios that are impractical to do manually. While the emphasis is usually all about maximising the experience, beacons also allow the collection of data so that it’s possible to learn from current or past installations.

Beacons are small, battery powered devices that can last months to years without changing the battery. They are detected by smartphones, gateways or single board computers such as Raspberry Pi.

We have immersive experience clients such as dreamthinkspeak, Playlines, Punchdrunk, Sophie Jump using our beacons. We also provide consultancy an example of which is Royal Museums Greenwich’s AR immersive experience for which we have a case study.

Beacons help make immersive experiences more physical and magical.

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Making an iBeacon Using ESP32

Circuit Digest has a new tutorial ESP32 based Bluetooth iBeacon. ESP32 is a small single board computer that can easily be programmed to do different tasks. Many ESP32 boards include Bluetooth so it’s possible to program them to be an iBeacon.

The article first explains how to detect beacons on Android using nRF Connect. This is similar to our post Testing if a Beacon is Working. There’s also a useful table that explains the different ranges for received signal strength (RSSI):

Creating your own beacons means you can customise the advertising and do other IoT-related things at the same. The downside is bare ESP32 boards aren’t as physically robust, easy to configure nor power friendly as a dedicated beacon.

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Faraday RF-Shield Bags in Stock

We have Faraday Radio Frequency RF shield nylon bags in stock. Specially made for us using stronger anti-RF fabric, we have tested this bag shields even our ultra long range Bluetooth beacons.

Faraday bags can be very useful during development when you want to bring beacons in and out of range or need to hide development beacons. They are also useful during setup when you want to shield uncommissioned beacons temporarily.

These bags were originally designed for military, intelligence and police agencies to prevent seized devices from being remotely altered. They shield WiFi, Bluetooth and phone signals up to 70dBm. They can also be used with phones and tablets for personal anti-radiation health reasons, preventing tracking or avoiding communication when you don’t want to be interrupted.

The smallest gap in a Faraday bag can cause radio leakage. Hence, the top has velcro to allow it to be rolled over and securely fastened for full radio blocking.