Being a bit more specific: I would like to know whether there's a Smartphone that can detect an RFID tag from few feet away using its original HW (no external devices) and OS capabilities.
Any comment/direction to reading material will be highly appreciated.
I think the answer depends on your use of the word "RFID Tag". In the classic sense, a read-only transponder, equivalent to a bar code, the answer is not yet. There are proposals for 2.4 GHz RFID that could use existing WIFI chipsets to identify nearby objects. Nothing standard or accepted is available.
However, based on the application you describe. One potential answer may be to flip how you are thinking of setting this up. If you just need to know if a certian, unique, person is near a spot in the mall, maybe instead of their phone looking for an RFID tag you need a low cost bluetooth sniffer (connected to a low cost computing board) looking for their phone, via bluetooth MAC addresses, within say 5m. As long as the customer has bluetooth enabled, has signed up for your service and your read points are connected to the internet this approach should cover your use case.
Basically the possibility is very low.
Near field refers the the property of RF fields with very close proximity between the devices. In the case of NFC as it applies here the devices are even closer, in what is termed the "Reactive near-field". Moving further away these properties are lost.
From Wikipedia: "Theoretical working distance with compact standard antennas: up to 20 cm (practical working distance of about 4 centimeters)"
I just found this solution:
http://www.ugrokit.com/
I don't have any experience with it.
Any android device with NFC chip and antenna embedded is capable enough to read RFID tags.
Related
I'd really love to learn to program cheap sensors and modules such as this one:
barometer sensor nRF51822 bluetooth module ibeacon LPS22HB, CR2032 battery holder, specifically to use within iOS and Swift.
I reached out to the company who makes them and tried researching how to get started multiple times, but I really can't figure out where to start. There are also pre-programmed modules, but my interest is programming these cheap ones to fit my needs.
I have the linked module, and a few others, and they appear and can be connected to using beacon detector apps, but display no understandable info.
I'd like to read the barometer pressure reading to start. Help is highly appreciated, I'd love to start working with these.
EDIT/UPDATE: I was able to read the modules manufacture name on one of many iBeacon scanner apps I tried and their name is Yunjia. With this information I am able to find alot more details online about what I have. One website says for these chips I can use LightBlue (the app I used to find the manufacturer name) to modify, read, and write to the module. Any additional advice is welcomed, I'll be researching and testing things out.
I also found the Schematics along with some additional info hidden in the seller website.
Edit 2: I found the manufactures little YouTube channel with some info, looks like I just have to do lots of research and testing and learn everything. https://www.youtube.com/channel/UCvqhWNqDE-v0je0X8XAEF2Q It contains some video instructions.
Edit 3: My short term goal of reading the barometer data was a success! After tons of digging I found I just had to write a value of 0x01 to turn on all sensors, then I was flooded with data and the barometer pressure in bytes which could be translated to the actual amount. Write 0x00 to trun off all sensors.
Apple's iBeacon framework is dirt-simple and very easy to use. It allows you to listen for beacons based a unique UUID, major id, and minor ID. It lets you know when a beacon enters or leaves range, and provides crude (immediate, near, medium, and far) distance values. You can create "beacon regions" that will notify your app when you enter or leave them. That's about it.
If you want to do something like read barometric pressure or temperature readings, you will need to either write your own low-level BLE code or use an existing library. My guess is that these modules are using very standard hardware and that you should be able to find libraries to read their specialized data.
Failing that, you will need specifications on their BLE interface and need to learn how to write Apple Core Bluetooth code. (The link you posted has zero specifications for the units. The only thing it provides is the numbers "nRF51822 bluetooth module ibeacon LPS22HB" (It's not in well-formed English so I don't know how to parse those descriptive terms. I'd google those numbers) Note that Core Bluetooth is a fairly low-level framework and not very easy to learn.
EDIT:
Googling "nRF51822", that is apparently an ARM based chip that includes radio hardware that supports BLE. It sounds like that is a general-purpose chip that vendor would use to build a BLE module. Given that, you'd probably have to reverse-engineer it to figure out how it works.
The "LPS22HB" appears to be a solid state pressure sensor that can be used to build a barometric pressure measurement device. It's no doubt interfaced with the "nRF51822". Without specs you're going to have a very hard time figuring out how it's interfaced however.
I'm developing navigation system for my university as some kind of research activity. I'm using SVGKit to display floor plans. And now I need to provide user locationing service for navigation and tracking. So here's my questions:
1) Do I need some special hardware installed in university (Cisco MSE for example, or some cheaper analogues), or I can apply some software/technologies to our current hardware for server-side user location determining? If I do, what equipment do I need for it? I mean, it would be one unit for the whole university, or one per each floor, or what?
2)
Q: Why doesn't the Redpin iPhone client conform to the iPhone SDK
Agreement? A: Apple does not provide a public API to retrieve WiFi
data. In order to get the iPhone client working we had to use a
private API, which is disallowed by the iPhone SDK Agreement.
(c) http://redpin.org/faq.html Does it mean that RedPin is unacceptable in AppStore, so I can't use it?
3)Does Navizon I.T.S. requires some specific hardware equipment except standart routers?
Thank you all, maybe you can offer me better solutions, I hope. Thanks in advance.
Indoor positioning is a very vast field and many different solutions are available which all use a different combination of hardware/software. Some need no specific hardware to work, others need a very expensive infrastructure to be put in place. In the end, it all depends on the accuracy you are trying to achieve. Here are the most common solutions used, I ordered them by the type of technology used:
Wifi: two main techniques are used here, trilateration and fingerprinting. Both do not require specific hardware if your uni already has deployed access points (APs). Trilateration converts signal strength to distance and then intersect circles (almost exactly like GPS). In general this has poorish accuracy and you need to know the exact position of APs for it to work. Fingerprinting is a pattern matching technique where you first build a wireless map of the environment and then match the measurement against this map.
Bluetooth: same techniques as above can be used with Bluetooth nodes. Of course, there's less Bluetooth nodes than Wifi so you might need to deploy some extra nodes for it to be accurate enough. Same accuracy as Wifi (roughly 5 meters)
Dead reckoning: uses an accelerometer, gyroscope and compass to calculate the speed of heading of the user. Needs to be initialized and calibrated regularly by another absolute positioning technique. Subject to drift so accuracy degrades quickly over time. Upside is its very cheap, no extra hardware or initial survey phase are needed.
UWB: very accurate techniques based on time of flight measurements. Requires expensive hardware for both transmitter and receiver. You can achieve cm accuracy with this but it's probably not what you're after
This is still an field of research so it's not that easy to find something that just works. I suggest contacting the IT department of your university, if they run a Cisco system, I know some of them provide some sort of positioning capabilities but I don't have much details.
As for your iPhone question, any app that accesses the private API to access Wifi measurements will be rejected by the App store, so you won't be able to publish anything that relies on Wifi. You can still use it for research purpose though, you'll just have to figure out the code yourself as there's no official documentation (some unofficial doc is out there though)
Good luck!
I would like to locate the iPhone in a building to build an application with similar features as the iPhone app of the American Museum of Natural History. There is no good GPS reception as there are also rooms in the cellar I would like to cover.
What can save me is that there is good wifi coverage in the whole area, so my idea was to triangulate the position based on the wifi base stations in range, whose positions are known. However I found no public API to find out which base stations are in range.
Questions
Do you have an idea how the app mentioned above manages to get the correct location indoors?
Could one add the wifi base stations manually to Apple's database and use the usual CoreLocation?
Do you have other ideas how to implement it?
Any help is very much appreciated!
Boundary conditions
The indoor navigation is only used during an event to guide guests new to the building, so no complex infrastructure should be installed.
There are approximately 14-18 rooms to be covered. They are in different parts of the building, so wiring everything up would be very costly.
The preferred solution would not require a server backend of any kind and would work with a list of wifi access points and their corresponding locations.
I wouldn't know about 1 and 2. But if you would implement such a thing, turn it around to save a lot of trouble: create your own free-of-charge wifi network, and let the network determine the location, either based on triangulation, or just based on the currently associated access point. Make their signal weak so you have one audible access point per room. Let the app ask a server in what room he appears to be. This will also work for any other mobile/pda/laptop.
As for other ideas: You could use bluetooth to do somewhat the same as you're planning for wifi. You can't do everything with bluetooth, but listing devices seems to be one possibility. So just put a bluetooth device in every room. Bluetooth range is limited by definition.
Another one would be to use the microphone in conjunction with a high pitched sound which identifies the room, but that would cause trouble with dogs (for blind people), attract bats, and repel mice at the same time. Better focus on an RF based solution ;-)
You can also check out Navizon's indoor positioning system:
http://www.navizon.com/product-navizon-indoor-triangulation-system
Their system is able to locate iPhones by using the WiFi signals transmitted by the device and doesn't require an app to run on the phone to locate it. It can locate any other WiFi enabled device for that matter.
Check out wirelesswerx.com They seem to be doing indoor location using Bluetooth and it looks like they can do permanent install or temporary for events.
Is there is a way to determine an iPhone's exact location (indoors, and to a distance of just a couple of feet) via use of radio/antenna's or some other infrastructure located around premises (i.e a hospital, shopping mall, school). Will appreciate any ideas/direction (technologies, research) as for how to overcome this limitation.
If you mean for an area you have control over (setting up a location network for a specific school/hospital) as opposed to generic location, you'd be able to triangulate your position based on wifi signal power for APs with known locations.
If you wanted it to be a generic solution, and you know there would be multiple APs in/around the buildings you wanted, you could triangulate all wifi signals while you have GPS outside the building, and then reference those locations when you lose gps accuracy. The first part is something that many wardriving applications already do.
Here's an article describing a commercial technology for this purpose in high-level detail: link
And here's a link to a SO page where people have started discussing possible methodologies: link
Use the GPS and hope that you got good coverage.
Other than this, you can deploy several wifi hotspots that can measure the signal strength for each packet and do a triangulation to calculate the iPhone position with regards to three or more of these hotspots based on the signal strength each of them measured.
A quick search for "signal triangulation" on the internet reveals a Wi-Fi Based Real-Time Location Tracking technology from Cisco. I have not used it, so I can't vouch for it; and I suspect it's rather expensive. There might be other solutions as well.
The alternative would be to buy several wifi routers or access points and flash them with your own version of the firmware. You can probably use OpenWRT or DD-WRT as a base for this.
Does anyone know what kind of range can you get from the iPhone
bluetooth? Also, would the connection be strictly one to one? I know you
can choose from a number of peers to connect to but once the connection
is established, it seems you can only transfer data between one peer? So
basically, is it possible to create some kind of "multiplayer" experience?
Just answering the range part of your question...
The 10 meter figure for class 2 devices (of which the iPhone is an example) is very much a guideline.
The range of a Bluetooth device is limited by many real world factors. The 2.4 GHz radio frequency used by Bluetooth is strongly absorbed by water. For example, consider an iPhone connected to a Bluetooth mono headset. If the headset is in one ear and the iPhone is in your trouser pocket on the opposite side of your body, then there's a lot of water between the two devices. This will often cause a significant amount of packet loss in practice (you can hear this in the audio being carried). So, in this case, the range is about one meter.
At the opposite extreme, two class 2 devices separated by nothing more than clear air can get ranges of hundreds of meters.
Other factors that influence things are:
Interference - Lots of things use 2.4 GHz. WiFi, for example can cause problems.
Antenna design - Space and cost constraints often mean that the antenna design is sub-optimal. I don't know how good the iPhone is in this respect.
Walls - Generally walls attenuate Bluetooth signals. However, sometimes they are useful reflectors.
Quality of hardware - Some chips work better than others. Even different firmware revisions of the same chip may perform differently. Different versions of the iPhone probably have (or will have) different chips in them.
Protocol - It is possible to work around poor signal quality with error correction and retransmission. Even if the iPhone SDK forces you to use a particular protocol, careful design of your application can make a difference.
So, in summary, you should probably do some real world tests.
The connection is one-to-one, but you can create an adhoc network with one of the phones acting as the master/coordinator. The other phones would route all their communication through the master/coordinator.
One device can theoretically connect to 7 devices. according to the master-slave role, the device can multiplex between each of them giving the user an impression that you are connected to all of them simultaneously. Bluetooth specification does not stop you from doing that.This is theory.
Now for the iphone, whether it can connect to to more than one device can only be answered by apple or someone who knows the iphone bluetooth API. But I am pretty sure the bluetooth chip inside iphone should be able to connect to more than one device.
Range is essentially going to be good enough for a normal sized room to be covered. It can be longer or shorter depending on environmental circumstances, but remember that bluetooth was created to implement short range connections.
A bluetooth device can be part of a piconet of eight devices, one master and up to seven slaves. The slaves cannot communicate with each other, they must talk through the master, think of a star topology with the master in the center. The iPhone SDK has a GameKit framework that can be used to create the network for multiplayer games. Go to developer.apple.com at look at the GKTank and GKRocket sample code to see how it's used. These games only support two players, but the GameKit framework supports more. Look at the app store and you will see games that have four or more players.
Hope this helps to get started.
Apple iPhone 3G has a Class 2 bluetooth module. Class 2 Bluetooth devices have a communication range of 10 meters.
At a given instance a device can connect to just one device because it follows a master/slave communication model. But still we can perform a multiplexing. So we can virtually connect to more than 1 device and by rapidly changing the connected device.
I found a good article here. It explains bluetooth very well.
According to the my knowledge, multicasting is not impossible with bluetooth. So gaining a multiplayer experience is NOT impossible.
The bluetooth in the iPhone is Class-2, with a 10-meter range, approximately.
Unfortunately I can't answer the other parts of your question.
One device can be connected up to 8 others. It all depends on the iPhone bluetooth API (which I don't know anything about), but with Bluetooth itself you could then send data to multiple devices.
I tether my iPhone to my laptop over bluetooth every day, and I seem to remember having done that at the same time as using a bluetooth headset. YMMV.
It’s the latest incarnation of Bluetooth, the wireless device-to-device technology that allows your phone to talk to headsets, car stereos, keyboards and other devices directly, without the need for a router or shared wireless network.