iBeacon, Eddystone, Bluetooth, IoT sensor beacons, apps, platforms
There’s a startup, GrowLogic in Australia, developing the next generation of smart agriculture to increase productivity and reduce risk. They have an inspirational image showing what’s possible:
They are achieving this using Bluetooth mesh that’s a proprietary mesh solution from Wirepas rather than Bluetooth SIG mesh.
There’s a new paper by Seyed Mahdi Darroudi, Raül Caldera-Sànchez and Carles Gomez of Department of Network Engineering, Universitat Politècnica de Catalunya/Fundació, Spain on Bluetooth Mesh Energy Consumption: A Model.
They set up some experiments to measure current consumption under various parameters:
They found that a sensor device running on a simple 235 mAh battery, sending a data message every 10 secs, can achieve a lifetime of up to 15.6 months.
This battery is probably a CR2032 battery. Read our post on Beacon Battery Size, Type, Capacity and Life for typical beacons battery sizes and capacities.
Read about Beacons and the Bluetooth Mesh
There’s recent new research on The Bluetooth Mesh Standard: An Overview and Experimental Evaluation (pdf) by Mathias Baert, Jen Rossey, Adnan Shahid ID and Jeroen Hoebeke of Ghent University.
The paper explains how the Bluetooth Mesh Standard came about to address the problem of the variety of BLE meshing solutions that were not interoperable. It includes a great introduction to Bluetooth LE and Mesh with some statistical and experimental insights into mesh performance.
The authors explain how the choice of the use of advertising advertising at 100% duty cycle for lower end-to-end delay has degraded the low energy advantage of BLE advertising thus limiting the usefulness in power (battery) sensitive applications.
The paper contains some useful insights:
“It is clear that there are a lot of factors influencing the communication flows within a Bluetooth Mesh network, requiring more advanced management mechanism for optimizing the performance of the mesh network.”
However, the research had some limitations. Noise was simulated by introducing non-mesh beacons advertising every 20ms. This wasn’t very realistic given that most beacons advertise in the range 100ms to 1000ms. Re-transmit time was considered that complicated calculations – especially as re-transmit is application specific. It wasn’t mentioned that in many mesh sensing applications, unacknowledged messages are acceptable such that there’s no re-transmit. Also, the affect of other mesh network traffic, on the round trip time, wasn’t considered – only one mesh transmission at a time was considered.
Read about Beacons and the Bluetooth Mesh
There’s a new Bluetooth LE Wiki maintained by our founder, Simon Judge:
The Wiki includes information about Bluetooth LE idioms such as advertising, MAC address, Bluetooth name, GATT, transmit power, measured power, range, RSSI, mesh and the new direction finding feature. It also has links to hardware and programming information.
Beacons are small computers with a complete System on a Chip (SoC). There are four main companies that manufacturer SoCs: TI, Dialog, NXP and Nordic. Nordic is the most popular SoC for use in beacons, mainly because of the lower (tool) license cost and ease for beacon manufacturers developing the software (actually called firmware) that runs in the beacons.
Nordic has a new free Wireless Quarter Magazine that showcases uses of Nordic SoCs in many types of device, not just beacons.
Learn about:
There’s a thought provoking article, by Lorenzo Amicucci, on the Nordic Semiconductor blog on End-User Factors Impacting Industrial IoT Connectivity. Nordic is the manufacturer of the System-on-a Chip (SoC) in most beacons and Lorenzo is one of their Business Development Managers. While the article talks about Industrial IoT Connectivity and by implication Bluetooth Mesh, the insights are applicable to any project that has to choose between standard or proprietary technology.
The main conclusion is that the best solution from a technical perspective is not always best for the customer. Instead, the best solution should depend on the longer-term business strategy. While a proprietary technology can have the advantage of differentiating your offering it can suffer from future limited supplier availability and possibly shorter lifetime of the technology. Large rollouts:
“…want the confidence that a huge capital spend won’t be wasted on a technology that will be left obsolete in a couple of years.”
More specfically, new and second sourced products from other vendors need to guarantee interoperability for the lifetime of your project.
Read about Generic Beacons
Nordic, who provide the System on a Chip (SoC) in many beacons, have released v2 of their Mesh SDK that implements standard Bluetooth Mesh.
The main improvements are around support for Bluetooth GATT. It’s now possible for devices such as commercial beacons or smartphones to participate in the mesh via the GATT Proxy mechanism. It’s also possible for devices such as smartphones to provision new devices via GATT through Provisioning Bearer GATT (PB_GATT) rather than via firmware API or the serial API. Unfortunately, there are currently no app examples so there’s a large learning curve and development mountain to overcome to implement products based on these mechanisms.
Martin Woolley, who works for the Bluetooth organisation as an evangelist, has new slides (PDF – needs login at Google for some reason) from a Bluetooth Mesh talk at DroidConIT. The slides explain many of the mesh concepts. Here’s the slide showing the GATT proxy mechanism:
The documentation for Mesh v2 is on the Nordic web site.
Mouser has a free ezine called ‘Methods’ (pdf) that has in-depth articles on the latest advances in Bluetooth.
Steven Hegenderfer, Director of Developer Programs at Bluetooth SIG explains how Bluetooth 5 will enable design engineers to pioneer innovative solutions. Steven Keeping shows how Bluetooth has evolved and Barry Manz explains Bluetooth Mesh Networking and beacons.
Read more about Bluetooth mesh on our web site.
Beacons are small computers with a complete System on a Chip (SoC). There are four main companies that manufacturer SoCs: TI, Dialog, NXP and Nordic. Nordic is the most popular SoC for use in beacons, mainly because of the lower (tool) license cost and ease for beacon manufacturers developing the software (actually called firmware) that runs in the beacons.
Nordic has a new free Wireless Quarter Magazine that showcases uses of Nordic SoCs in many types of device, not just beacons.
The magazine also has articles on how Nordic is the first to launch a Bluetooth mesh Software Development Kit, how Mesh strengthens Bluetooth wireless’ IoT credentials and explains Bluetooth 5’s advertising extensions. The article says of Bluetooth 5’s advertising extensions:
“Advertising extensions, periodic advertisements, and connectionless broadcast will have a major impact on beacons”
However, the article says:
“This won’t happen overnight because few current smartphones incorporate Bluetooth 5, but expect beacons to proliferate over the next several years as new smartphones are rolled out”
A beacon has many settings such as the mode (iBeacon, Eddystone), transmission (ids or URL), power and advertising period. These settings are set via the manufacture app. However, what happens if the beacon is switched off via a button on the side of the button? What happens if the battery is removed? What happens to the settings?
First of all, if you turn off a beacon via a side switch beacons don’t power down but instead go into a very low power sleep mode.
All beacons have a portion of non-volatile flash memory that can be used to save values even when the power is removed by taking out the battery or removing from a USB slot. This means for almost all beacons, removing the power doesn’t cause the beacon to lose its settings. We say ‘almost all’ because we have found one exception to be Sky beacons that while they retain settings when the side switch is pressed on/off, they don’t retain settings if the battery is removed. This is because the firmware (code) in the beacon isn’t saving settings to non-volatile memory.
One thing to be aware of is that the non-volatile memory can only be updated so many times before it stops working. The number of times is very large and isn’t of consequence unless you have your own app that is frequently programatically changing settings. However, for some specialist beacons, for example mesh beacons, internally saved data can and will change more often thus introducing the possibly that beacons can become ‘worn out’ if the software isn’t designed to reduce the frequency of changed saved data.