I am working with RFID, using Motorola FX7400 reader to read tags, all that without much trouble.
This reader operates in a determined frequency(902 MHz to 928 MHz).
I want to limit this frequency to two bands, one going from 902 to 907 and another going from 915 to 928. I searched the API for something like that but I couldn't find anything. Is that possible? Has anyone tried that? Someone? Please?
For everyone with the same problem: The solution I arrived is that I need to put a firmware who meets that criteria.
I've got this answer in a RFID training, with people who has expertise with this tecnology.
This answer is applicable only for Motorola FX Series. For other brands and series, consult your vendor.
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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.
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/
I wrote some code that processes 135,000 books. I just got word from my retailer that 983 books seem to have an issue and is blaming my code for "screwing up" his inventory. I have a friend on the inside that says that there has been an on going issue with his inventory and it doesnt look to be me.
I'm thinking that if the issue was my code, more than .73% (983/135,000) of the data would be affected. How do I reply to him in mathematical terms to disprove his theory that it was my code?
Maybe exactly 983 books have a cedilla. Or Japanese characters. Or diphthongs.
I don't think there's any way you can use statistics here that won't cause statisticians to cringe.
Why don't you just offer a 0.73% discount to your fee, based on the outcome? :-)
Or, offer to fix the problem, meaning that they'll have to provide the information as to why they think they're screwed up.
In other words, make them specify what "screwed up" actually means. Do they not open in the reader? Do they open but characters or formatting are incorrect? Do they "brick" the reading devices?
Without real information, there's little you can do.
Ok, so I go this VoIP service and need a simple test of the sound quality transmitted. 2 VMs will "talk", and the tests will be done by a third computer. We have the record of the sound spoken and another recording of the sound received(.wav). The testing computer receives both files (pre and pos transmission, pos-transmission should have a little noise or errors) and need to compare the sound quality between then. The only relevant info, would be an output saying how good the quality is at he receiver end. (something like 0.0 - 1.0 score) I'm having a lot of trouble comparing the 2 sounds recorded, any insight and help would be great. Oh yeah, this must be automatized, so there is no one to listen both records and say how bad one of then is. The computer should be able to determine the final quality.
Sorry for any mistake, English is not my first language, and thanks again for any possible help.
The question is very interesting, but unfortunately you have thin chances of getting a perfect solution since it is an open problem. You might be interested in PESQ (Perceptual Evaluation of Speech Quality) (implementation at: http://www.itu.int/rec/T-REC-P.862-200102-I/en)
provided GPS will not work precisely in closed environment like rooms etc,I m interested to know whether Accelerometer can be used to find the position of object relative to certain point? If not then what other technology iphone4 provides to cater it?
Thanks
The accelerometer cannot reliably provide location information, even with the aid of the gyroscope. GPS is the best you are likely to get.
OTOH, work-arounds abound in the augmented-reality space. Consider the ARDefender game.