Help! Alternatives to RFID use on iPhone?

Discussion in 'iOS Programming' started by Reach9, Aug 25, 2013.

  1. Reach9 macrumors 68020

    Reach9

    Joined:
    Aug 17, 2010
    Location:
    In America
    #1
    Hey guys, we're working on an Engineering university project and was wondering if we could get feedback or advice from the community here.

    We're trying to notify someone (an admin) using an iPhone (through an app) if a person has passed through a boiler room of a building, and whether they are near the door or not.
    The usual person who is walking past the door would have a smartphone.

    We initially thought about putting RFID tags on the doors which would sense the smartphone the person is carrying, as they walk past the door. This would show up on the app (that the admin is using) as "someone is near the boiler room door" and once they leave a specific field then it would show up on the app as "nobody is near the boiler room door".
    Hope I made sense.

    Now unfortunately we realized that the iPhone does not have any RFID capabilities, and we want to allow the admin to use the basic iPhone hardware (the admin is not buying external RFID readers). All major Android phones have NFC technology, so they should have RFID capabilities. But we want the admin to be able to use any phone (specifically the iPhone).

    Is there any alternative to RFID we could use? We were thinking of having motion or weight sensors on the doors to detect whether someone has passed it or near it (some doors are very close to each other, would it still work?) and having it send out a simple boolean "T or F" to a cloud system if it senses someone. The iPhone would then pull the information from the cloud and onto the app, allowing the admin to see it in real time.

    Is this possible? How difficult would this be?
    How expensive would such sensors that, when triggered, they push a boolean to the cloud be?
    How would the app pull the data from the cloud?

    Basically the end user should be able to see the status of the boiler room door area through their basic smartphone hardware (including iPhone).

    Any feedback would be appreciated.
     
  2. Duncan C macrumors 6502a

    Duncan C

    Joined:
    Jan 21, 2008
    Location:
    Northern Virginia
    #2

    A couple of ideas come to mind:

    Put a Bluetooth device on the door, and use bluetooth based geofencing on the iPhone to wake up your app when the user enters. However, this would require that the people using it cooperate.

    There are WiFi SSID detectors that sense the ID of every WiFi enabled device that comes in range. You could use one of those to detect any WiFi enabled smartphone that enters the area. That might be too long-range however.

    The simplest, most reliable approach, though, is probably not smartphone based. Put a passive IR (PIR) motion sensor on each door, connected to a device that sends info over the network. You could rig up a device with an Arduino that would do this for less than $200, including the Arduino, PIR motion sensor and WiFi unit.
     
  3. Reach9 thread starter macrumors 68020

    Reach9

    Joined:
    Aug 17, 2010
    Location:
    In America
    #3
    Hi Duncan, I really appreciate your response.

    Bluetooth Geofencing is very interesting, unfortunately I feel that the battery life of the Bluetooth device on the door will be pretty poor.

    You're right, it seems as though a non-smartphone based solution would work the best. But I do want to integrate such a solution with a smartphone.

    If I do use the Arduino method, how much would each PIR sensor cost?
    Also, what would be the battery life to power such a device?
    If i'm understanding this right, it would cost at least $200 to set it up for the entire building as long as it's on the same Wifi network?

    What if I use a proximity/motion sensor ([on the door] to detect whether anyone has passed by), and then program a microcontroller (a component with the sensor) to send a data packet over Wifi to some sort of cloud infrastructure (using a Wifi communication chip, another component), and then have the app pull the data from there?

    Do you know how feasible that would be? How much would it cost?
     
  4. 1458279 Suspended

    1458279

    Joined:
    May 1, 2010
    Location:
    California
    #4
    I don't know if this applies, but BTLE (Blue Tooth Low Energy) is supposed to use those button batteries and can last years. This is a part of the API as of about a year ago (iOS 6 I think). They are supposed to be used for things like temp/humidity sensors and are supposed to be dirt cheap.

    Again, I don't know if BTLE will meet your specs or not, but worth reading about.

    http://en.wikipedia.org/wiki/Bluetooth_low_energy
     
  5. Duncan C macrumors 6502a

    Duncan C

    Joined:
    Jan 21, 2008
    Location:
    Northern Virginia
    #5
    As the other poster said, bluetooth low energy devices last a long time on a set of batteries. You could also set up a bluetooth device using AC power so it would run forever.

    As for the proximity/motion sensor, the cheapest way to go would probably be to use a single microcontroller like an Arduino with multiple PIR motion sensors, one for each door you want to monitor, and a single WiFi unit.

    I mention Arduino specifically because they are widely used, modular, and available in all kinds of configurations. You can get PIR sensor modules, bluetooth modules, WiFi modules, and lots of other goodies that just plug in and work. The Arduino has multiple i/o channels, so you should be able to monitor multiple doors with a single Arduino.

    I don't know the costs off the top of my head, but I'm guessing that you could put together the hardware for such a system for a couple of hundred dollars.
     
  6. Amazing Iceman macrumors 68040

    Amazing Iceman

    Joined:
    Nov 8, 2008
    Location:
    Florida, U.S.A.
    #6
    Bluetooth sounds great, but if the intruder (or person) turns off Bluetooth on his device, then there's nothing to detect.

    As someone else suggested before, an IR detector and why not a camera too (some new cameras have motion detectors in them) may be the best solution.

    Also, I'm not sure if a phone with RFID would still be detectable after you turn it off, which would defeat the purpose of this project.
     
  7. 1458279 Suspended

    1458279

    Joined:
    May 1, 2010
    Location:
    California
    #7
    +1
    I've looked into those Arduino and PI and they look awesome. So much you can do with those things.
     

Share This Page