Detecting Temperature With Beacons

Some sensor beacons can be used to monitor temperature. The first thing to consider when comparing temperature beacons is whether they have a dedicated hardware temperature sensor. Some beacons have a temperature sensor inside the main chip (System on a Chip – SoC) that’s less accurate and has less precision. The sensor is mainly there to give an indication of the chip temperature, not the ambient (outside the beacon) temperature. Most beacons only transmit for the order of 1ms every 10 to 5 seconds and enter a very low power state the remainder of the time. This means they not only use low power but don’t significantly heat the SoC. This means the SoC roughly tracks the outside temperature.

In our sensor beacon listings, when we say a beacon has a temperature sensing it has a separate hardware sensor, usually the Sensirion SHT20, providing more accuracy and precision than the sensor in a SoC. Some of our beacons, such as the Minew i3 and i7 have an internal SoC temperature sensor that’s readable but we don’t classify that as a sensor beacon.

The next thing to consider is the casing. In order to quickly track ambient temperature, the casing needs to be open somewhere and usually have a hole. Beacons that say they are waterproof and have temperature sensing won’t track ambient temperature well.

We have had customers use temperature sensing beacons in scientific situations and where they need to periodically calibrate sensing equipment. How do you calibrate temperature sensor beacons? The SHT20 is has a long term drift of only <0.04 deg C/year (the humidity reading vaies difts by <0.5%RH/year) so it doesn’t need calibration for most situations. However, if you need better than this, or check calibration, you will need to periodically calibrate in the software of the device (usually an app) that receives the beacon sensor data.

New Physical Web Association

Last April we asked if the Physical Web was dead and mentioned that a group of people, led by Agustin Musi from Switzerland, was contemplating creating PhysicalWeb2. The Physical Web Association (PHWA) has now been created as a non-profit association with the goal of driving the development, community, and adoption of the Physical Web. The PHWA is now accepting memberships.

A refreshed TestFlight version of the PhyWeb iOS app is available to members. This new app will be promoted via advertising and the press. In time, the PHWA aims to develop a native app kit to add the Physical Web to existing apps, develop brand-neutral apps for iOS and Android and host a metadata service as, presumably, a substitute for the google Physical Web Proxy.

Detecting Movement With Beacons

There are various types of movement that can be detected by beacons:

Movement between zones – This is large scale movement between, for example, rooms. This relies on devices detecting the beacons and relaying the information to software that, stores historical location, plots positions and creates alerts. This is the basis for Real Time Locating Systems (RTLS).

Movement from stationary – This is when something goes from being stationary to moving. There are two ways to do this. You can look at the xyz from a beacon accelerometer to determine it has started moving. Alternatively, some beacons such as the iB003 have motion triggred advertising so you will only see the beacon when it moves.

Falling – Again you can look at the xyz from a beacon accelerometer to determine a beacon is falling. Alternatively, you can use a more intelligent beacon such as the iBS01G that does this for you and just gives indications of a start/during/end of a fall as values in the advertising data.

Vibration – The xyz can be used to determine the degree of the movement and hence vibration.

Posture detection – This is more advanced analysis of the xyz that works out, for example, if someone is walking, running, sitting or standing. Another use is the analysis of sports (e.g. golf, squash, tennis, badminton) swings to determine the type of movement and score the movement.

There also scenarios outside the above that are also possible. For example, we had a customer wanting to know if their forklift truck hadn’t been moving for 2 minutes so as to make best use of it.

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Beacon Within Existing Systems

There’s a trend for beacons becoming parts of existing systems rather than being the main reason for having a system. The two way radio admin system (from Motorola) was one of the early examples. Newer examples are smart desk/meeting room systems, BlindSquare for navigation and (Cisco Meraki) WiFi access points.

Middleware used to create systems is also increasingly including support for beacons. An example is IBM’s MobileFirst Foundation service that has recently provided for beacons via a MobileFirst Adapter. This allows you to easily use beacons within mobile apps with data being stored in the IBM Cloud.

BlindSquare and Beacons

BlindSquare is a popular accessible GPS application developed for the blind and visually impaired. It describes the environment, announces points of interest and street intersections. BlindSquare also works with iBeacons.

An example of use of BlindSquare with beacons is Melbourne Zoo that allows people with visual impairments to get to parts of the zoo that are out of bounds to guide dogs.

More details how to use BlindSquare with iBeacons can be found in the BlindSquare user guide.

Bluetooth Mesh Proxy Kit Available

The Bluetooth Mesh Proxy Kit has recently become available. It provides a great explanation how Bluetooth mesh uses standard Bluetooth LE. It describes the types of mesh node and more specifically, the ‘proxy’ type that allows ordinarily non-mesh devices, such as smartphones, to participate in a mesh network.

There’s a client and server side demo written in Javascript. The demo uses node.js on a Raspberry Pi and Web Bluetooth for the client. While this demonstrates the concepts, it’s more likely production implementations will be in c/c++.

Prognostics, Predictive Maintainance Using Sensor Beacons

A growing use of sensor beacons is in prognostics. Prognostics replaces human inspection with continuously automated monitoring. This cuts costs and potentially detects when things are about to fail rather than when they have failed. This makes processes proactive rather than reactive thus providing for smoother process planning and reducing the knock-on affects of failures. It can also reduce the need for over excessive and costly component replacement that’s sometimes used to reduce in-process failure.

Prognostics is implemented by examining the time series data from sensors, such as those monitoring temperature or vibration, in order to detect anomalies and make forecasts on the remaining useful life of components. The problems with analysing such data values are that they are usually complex and noisy.

Machine learning’s capacity to analyse very large amounts of high dimensional data can take prognostics to a new level. In some circumstances, adding in additional data such as audio and image data can enhance the capabilities and provide for continuously self-learning systems.

A downside of using machine learning is that it requires lots of data. This usually requires a gateway, smartphone, tablet or IoT Edge device to collect initial data. Once the data has been obtained, it need to be categorised, filtered and converted into a form suitable for machine learning. The machine learning results in a ‘model’ that can be used in production systems to provide for classification and prediction.

Update on the Use of Beacons on Aircraft

Last year we wrote about how Beacons might be classed as Personal Electronic Devices (PED) and how companies such as Samsonite were already using tracker beacons in some of their luggage. Since then, there have been some new airline baggage rules that have put some ‘smart’ baggage firms out of business.

The new rules focus more on the batteries than the use of (Bluetooth) wireless. Lithium-ion batteries pose a fire risk, especially when left unattended in the hold. In the US, smart cases are banned from the hold unless the batteries can be removed. The IATA has a paper (pdf) on smart baggage with integrated batteries.

The focus is on baggage (and hence batteries) in the hold. Devices need to be able to be deactivated and/or taken into the cabin rather than stored in the hold.

The CAA says:

“Lithium batteries are very safe, but because of their high energy, if they are not treated with care or if they are abused or have a manufacturing fault, they can catch fire”

The main risk is that baggage gets damaged which then affects the enclosed batteries.

New Long Range (200m), Waterproof i3 in Stock

We have a new variant of the waterproof, long range (up to 200m) i3 in stock. This differs to the previous i3 in that it uses the newer Nordic nRF52 SoC for improved battery life up to 5 years depending on the settings and the type of batteries (takes 2 x AA).

This beacon advertises up to 6 channels that can be iBeacon, Eddystone UID, Eddystone URL, Eddystone TLM and device info.

Radioland’s New X1 Beacon in Stock

We have Radioland’s New X1 beacon in stock that advertises iBeacon. It features two included AA batteries that, depending on settings, can last up to 5 years. This is possible because the beacon uses the TI CC2640 chip that consumes low power. There’s a slider switch on the back to turn the beacon on and off.

This beacon is also waterproof and comes with a separate backplate that allows the beacon to be mounted on a surface.