Category: faq

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:

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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.

MQTT vs HTTP for Bluetooth WiFi Gateways?

Bluetooth WiFi gateways offer MQTT and/or HTTP for sending data to servers/cloud services. We are often asked which should be used. HTTP is what’s used by your web browser to fetch and send data to web servers. In very high level terms, MQTT accomplishes a similar thing but is better optimised for mobile devices and the Internet of Things.

HTTP is very ‘chatty’ which means it’s more complex, code wise, to implement at the sending end and wastes a lot of data and processing power getting information from sender to receiver. You can think of HTTP as wrapping the data within lots other data that gets sent backwards and forwards. MQ Telemetry Transport Protocol (MQTT) came out of IBM, is now an ISO standard and uses lightweight publish/subscribe messaging. It requires a smaller code footprint at the sender and uses less network bandwidth. This matters most when you are trying to get the maximum transactions per second or are being billed for data use.

Bluetooth WiFi gateways are powered via USB and have reasonably powerful microcontrollers so MQTT’s efficient processing doesn’t matter that much. The more efficient processing is more applicable to apps running on mobile devices. For example, Facebook uses MQTT which saves battery life.

However, being lightweight, MQTT offers faster response times and lower data use than HTTP that, while not necessarily being of much of an advantantage for the BLE WiFi gateway, benefits the communications medium and server side. The communications medium, that can sometimes be cellular or be data constrained, uses (and possibly bills) less data. More crucially, the server can process more requests in less time. MQTT tends to be better when connectivity is intermittent, bandwidth is at a premium and throughput is critical.

In summary, MQTT has lower latency and is more efficient. Whether these are required advantages depends on your actual project. If you need more help, consider our development services.

Is There a Beacon That Works Without Bluetooth On?

We sometimes get asked if it’s possible that smartphones can detect beacons without Bluetooth being on. All beacons are based on Bluetooth LE that, in turn, relies on Bluetooth being switched on in the phone to scan for beacons. There’s no magic underling operating system mechanism on iOS nor Android that allows you to use Bluetooth without the user having Bluetooth on.

More users are leaving their Bluetooth on due to the proliferation of connecting with other devices such as cars, Bluetooth headphones and smart speakers. If you are writing an app you should take steps to detect if Bluetooth is on and prompt the user appropriately.

The phone and beacon industries need to better educate users that Bluetooth is no longer the heavy battery drainer it was in the early days of smartphones.

How Accurate is Bluetooth Direction Finding?

Bluetooth direction finding promises sub-meter accuracy. In practice, the accuracy varies depending on factors such as the locator hardware quality, radio signal noise, surfaces causing radio reflections, the accuracy of locator placement and beacon orientation. The sophistication of the location engine software in mitigating some of the aforementioned factors can improve the accuracy.

As a guideline, our Location Engine with the Minew G2/AR1 tends to find beacons with a maximum angular error range between 6° to 10°, depending on the above factors. The error in position due to an error in angle gets magnified with distance from the locator. Hence, the accuracy also depends on the distance between the locator and the beacon.

Here are graphs of error vs distance for 6° error and 10° error:

The above accuracies are for hardware such as the Minew G2/AR1 with PCB antennas 50mm apart. It’s expected that greater accuracies might be achieved with hardware having greater inter-antenna distances.

It can be seen that the sub-meter promise has caveats. We have some tips to help reduce angular errors. Averaging data, over time, also reduces angular error with the trade-off of increased latency of detecting location changes. As with all locating technologies, headline performance claims need to be carefully examined and are only achievable in particular situations.

Read about PrecisionRTLS™

Do You Have a Beacon That Makes a Sound When You Are Near?

The quick answer is no.

The longer answer is that beacons don’t know if anyone is near because they are not doing the listening. They just send out information. It’s possible to have a smartphone app see the beacon and the phone make a sound.

F6 Tracker Beacon

We also have special tracker type beacons to which an app can connect rather than just detect. Once connected, the app can cause the beacon to ring. However, only one app user can connect at a time.

What’s the Smallest iBeacon?

Small beacons are sometimes needed so that they remain unobtrusive or need to be embedded into larger devices. The smallest, cased, beacons we supply are:

E8 36mm x 23mm x 5mm
FSC-BP103 37.8mm x 33.8mm x 7.9 mm
U1 Thin 45mm x 25.5mm x 4.8mm

The compromise with small beacons is that they have CR2032 batteries that don’t last as long as larger battery beacons. If the beacons won’t be moving and you have access to USB power, consider using USB beacons that are also small.

Why Doesn’t the Manufacturer’s Configuration App Connect?

When in typical use, it’s not necessary to connect to a beacon. A beacon just advertises and is detected by a smartphone or Bluetooth gateway. However, to initially set up a beacon you usually connect via a smartphone app. The app might not connect for a number of reasons. Here are some tips:

  • Most beacons need to be put into ‘connectable’ mode. For example, for most AnkhMaway beacons this means tapping them sharply on a table until they ring – they remain connectable for 45 secs and once connected remain so until you have configured the beacon. For Axaet and Meeblue beacons they stay connectable for a few minutes after turning them on.
  • Make sure you are connecting to the correct beacon. This is especially important if you are seeing multiple Bluetooth devices in the list. For example, we had one customer who hadn’t removed the plastic battery slip and had been trying to connect to some other Bluetooth beacon/device.
  • Connecting, via what is a wireless interface, might not work first time. While most connections do happen first time, there can be radio interference and radio signal reflections that can cause the connection to fail. Some configuration apps re-try if the first connect fails while others don’t. Make sure you have tried a few times before concluding a particular scenario doesn’t work.
  • Some phones have a faulty Bluetooth beacon stack. That’s the Bluetooth software built into your phone. While you might be able to view the beacon, connecting to it to change settings uses more advanced functionality that’s sometimes faulty. Over time, we have discovered about 5% of our customers have such problems, more so on Android. It’s a much more common problem than a faulty beacon. You can isolate this possibility by trying a different phone and/or different phone OS type.
  • Don’t try connecting from more than one phone at a time. When connected, that phone has exclusive access to the beacon and other phones won’t be able to see the beacon and connect.
  • Make sure you are using the correct password to connect. It’s not the password on the sticker which is the web site technical area password.
  • Try rebooting your phone to reset the internal Bluetooth software.
  • Try resetting the beacon by removing and replacing the battery (where possible). This isn’t the same as turning off via a button press which usually only puts the beacon into hibernation and doesn’t restart the device.
  • Some configuration apps have known bugs. Read the BeaconZone technical area for your particular beacon manufacturer where we document known problems and workarounds.
  • The beacon could be faulty. This is actually a very rare occurrence and you should initially be considering other more likely possibilities (above). You can isolate this possibility if you have another similar beacon. Please contact us for replacement if you conclude you have a faulty beacon.

Why Doesn’t The Beacon Achieve The Specified Range?

The distance that a beacon can transmit is shown in the specification tab for each beacon. This is the maximum range specified by the manufacturer at maximum power under ideal conditions.

Here are some tips if the range is less than expected:

  • Make sure the beacon is operating in normal rather than configuration or connectable mode. Some beacons transmit differently or only for a limited time when they are in connectable mode. For example, with AnkhMaway beacons, make sure the mode has been set to ‘On’ either in the configuration app settings or via service/characteristic parameters.
  • Make sure the beacon is set to 0dBm transmit power (or higher) rather than a negative value that indicates the beacon is to transmit with reduced power.
  • Re-orient the beacon. Most beacons have antennas on the printed circuit board that have differing transmission characteristics depending on their orientation to the observer and whether they are shielded by other components such as the battery. Experiment with different orientations in each of the three dimensions.
  • Try a different observing device (phone). Different phones have different receiving characteristics.
  • Try at a different place. In rare circumstances, the area might be congested with 2.4GHz interference from other beacons, WiFi or other equipment. The area might have particular radio frequency (RF) blocking or reflective qualities.
  • If you can, try a different beacon of the same model to isolate whether it’s a faulty beacon.

The maximum specified range is rarely achieved for any beacon although there have been a cases where we have found beacons to be better than the specification.

All manufacturers, not just those whose beacons we sell, tend to specify the optimum range, outdoors, with no radio interference. You will experience reduced range indoors where there are radio reflections and obstacles. If you need a long range under all circumstances then we recommend you over-specify the beacon range and perhaps look at beacons with an ultra-long range.

What are the Estimated Distances for Tx Powers?

Beacons allow you to set the transmit power to levels such as -30dBm, -20dBm, -16dBm, -12dBm, -8dBm, -4dBm, 0dBm and +4dBm. The number of actual setting values depends on the beacon. 0dbm is the default power recommended for normal use. Our article on Choosing the Transmitted Power explains these values and how they relate to distance.

We are often asked ‘What are the Estimated Distance/s for Tx Powers?’. This depends on the beacon, the environment and the receiver. An analogy is someone shouting a word. How loud does someone have to shout to be heard a certain distance? It depends on how clear the person shouts, how much noise there is and how well the person listening can hear. With beacons it depends on the beacon (mainly antenna) design, how much radio frequency (RF) noise there is, the degree of RF reflections, the receiving ability of the device (smartphone or gateway) you are using and even the weather.

The only way to determine the relationship between distance and power is experimentally and it will likely change over time as the environment changes.