Calculate Distance between Arduino BLE shield and Phone - bluetooth

Is it possible to calculate the distance between an arduino bluetooth shield (BLE Shield 2.1) and cell phone? More specifically, when the cell phone is within <5 feet of the shield, I want it to perform an action. I know BLE Beacon technology is able to do this in a general sense (immediate, near, far) so I'm wondering if it is possible?
Looking through stack overflow, I've found the following answers but they are all dated:
Answer 1
Answer 2
I know that ultrasonic frequency and laser sight are both options but I am trying to keep costs low so I would prefer a way in which the distance is calculated without the use of an additional tool.

Yes you can use it for distance calculation based on RSSI (received signal strength). You should implement iBeacon on Arduino side as stated in Eirik M answer. The most important thing in my opinion is that you have to be aware of BLE/iBeacon precision.
Please read carefully the following articles to determine if iBeacon technology fits to your needs. If so, implementation should be straight forward.
Broadcasting power and RSSI
The Beacon Experiments: Low-Energy Bluetooth Devices in Action

If BLE beacons are good enough for you, it should be fairly easy to implement a beacon for the Arduino shield. There are a few things you need to be aware of, such as output power and antenna characteristics. I recommend to read up on beacon technology to understand how it works.

Related

Beacon/device that is able to receive signal from another beacon and pass it to smartphone

I've been searching in articles for some simple device that is able to do that(title), but I didnt find any. I am looking for a simple device that is able to get RSSI from some unique beacon in range and then pass it (reveiced RSSI value) to the smartphone(via bluetooth).
I thought about some "smart beacon" that is able to work bidirectional (Get signal from another beacon, then pass it to the smartphone). Has it ever been done?(If yes I would be grateful for any articles).
If I wouldn't find anything I will use another smartphone as that device.
I am unaware of any commercially available products that do this. A more common solution might be a device that scans for other beacons in the vicinity and reports them directly to a server.
The reason that reporting scanned beacons to a smartphone over BLE isn't a common solution is because it would be simpler for the phone to do the scanning itself. Why would you need a separate hardware device to do this?
Such a solution you propose might have the advantage of extending the range of the smartphone, but probably not by much. Consider that if the reliable range of BLE is 40 meters, then a phone 40 meters away from the device you suggest might be able to pick up beacons at most 80 meters away in the same direction. Practically speaking this would rarely even double the scan area covered by the phone simply working by itself.

Who manufacturers BLE devices with low distance or low tx power available or configurable

What BLE beacon models can be configuraged to only be detectable at around 5-7 meters?
I've only used one bluetooth manufacturer and getting the distance (using the signal strength (RSSI)) the distance was not consistently accurate enough. It seems the most accurate way to get distances is by setting the power level lower and only check whether you are in range or not.
I don't know how the power levels translate to distances, so just looking at the txPower on manufacturer sites does not help much. Preferably ones that are configurable and can also be configured to higher or even lower power levels.
You could play with power level (Kontakt IO beacons supports it) but what you want to achieve is really difficult.
To be short, here is great, detailed, explanation of everything what I would wrote.
Hope it helps...

How to use Bluetooth Low Energy badge for localization?

I know, this question has been asked a lot of times. Until yesterday i thought that the answer was "yes, it is possible but you can not obtain an accurate result of your position". My idea is to take a BLE badge in my hand and with other 4 devices, positioned on the ceiling, obtain my current position using the trilateration. After weeks of resarch, i concluded that this method could not be as accurate as i'd like it to be, so i went over.
Now, what about this video? Youtube by Loopd.
They use bluetooth badges, but how they obtain these results?
Thanks to everyone
The results of Bluetooth LE indoor location can be quite accurate, but it requires some processing of the raw signals rather than simple triangulation. Essentially you weight different beacons differently in your position calculation based on how far away they are and filter to smooth the result.
There is a working example as open source at http://vor.space/

Sending iBeacon signal strength(for distance) to arduino board

I have a project using quadcopter(ARDrone).
And i want to controlled it unmanned indoor, using arduino board and iBeacons.
iBeacons send signal strength and floor info to arduino board(inside ARDrone connected main board) and iphone for searching location in building. Project is just controlling drone to go to iphone's location by itself. All calculation parts are managed in server.(triangulation etc.)
Here are the questions.
How can arduino board receive bluetooth 4.0 signal and send it to
server? 4.0 signal can be received by bluetooth 2.0 module?
Do i need to build bluetooth 4.0 receiver module? Or are there any other ways?
In server, complicated calculation will be managed by programs in c++ language but simple things are handled by web language. php? jsp? or other lang which one is better?
and some hints for this project.
I really need your help. thanks;)
3. The calculations to identify the location from the received signal strength and location of the Beacons are fairly straightforward, so should be fine in which ever language you prefer. You will need to use Trilateration, once you have converted RSSI (received signal strength) into a distance.
4. The major challenge you will have is getting accurate distances, iBeacons as you know use Bluetooth LE, what you may not know is that this operates on a Microwave wavelength and so is easily disrupted by humidity in the air, as well as other objects like people. This means that the RSSI readings will jump about a bit, a basic way to overcome this is to take an average over several readings, even so the distances found will be rather inaccurate in many circumstances. To get an idea of the kind of readings that you will get for distance without compensating for environmental factors have a look at my presentation: "Factors effecting positional accuracy of iBeacons", that is based on Estimote iBeacons, but should be relevant for other brands as well, but you will need to do your own experiments to work out the relative errors. I was seeing distance readings that were +-2M away from the real location.
My name is Wojtek Borowicz, I'm a community evangelist at Estimote.
To add to what Chris Thomson (BTW, cool slide deck!) - your first two question can basically be reduced to a single answer: you need your receiver to support Bluetooth Smart on both the hardware and software side. So yes, you need a Bluetooth 4.0 module to receive Bluetooth 4.0 signal and you also need a Bluetooth 4.0 stack for your receiver to be able to 'interpret' that signal.

can bluetooth low energy be used like nfc - say printed to an ID badge?

I'm using my iPhone to scan in a complex 2D barcode. Problem is, the iPhone camera doesn't do so well at very close distances (less than 3 inches).
I was wondering if there were a way I could affix a Bluetooth low energy "sticker" to a piece of paper. The idea being instead of using the camera to scan a 2D barcode, I could just put my iPhone near the paper and "scan" it.
I'm extremely new to Bluetooth tech, so it's quite possible that what I'm asking for is completely ridiculous. Please forgive me, if that is the case.
Unlike NFC, Bluetooth Low-Energy devices need a power source, so it's imposible to just "print" them. They need a BLE chip and a battery to operate. So while you could use BLE same way you use NFC (proximity-based actions), you won't be able to do it with just a sticker.
Register at bluetooth sig for manufactorer id. Then put manufacturer id in advertisement package 0xff with id (16 bit) followed by the data. You must be sure your length is correct or iOS can't decode it.
For NFC, your scanner must be pretty close to the tag. But BLE devices work within several tens of meters without any problem. This is like an active RFID chip.
Of course, you need a power source for it. But if you print this BLE tag to a piece of expensive equipment, the cost of the tag and the battery is not a problem. You can use a button cell battery to power the BLE tag up. Let is broadcast/advertise some info once a second. Of course, you have to add some security mechanism if you want to be away from any replay attacks.

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