Tips of sensor to use?


Im going to make visuals on an event. I want the crowd to have the possibility to interact with the visuals through some kind of sensor. My idea is:

To give something I can track to maybe 20 people in the crowd, for them to hold in a hand Then I want to by tracking their handmovement make drawings in my visuals.

My two criteria for the tracking system is:

  1. Have to be something I can "lose". Something inexpensive
  2. Something not driven by batteries

Some ideas:

  1. Since most people today have cellphones, maybe find a way to track the gps signal from a cellphone? Any tips?
  2. Maybe connect small battery to IR-led to track with camera with IR filter. (not perfect solution since it probably will be lightshow among the audience and since i dont want to use batteries)

Any input welcomed!



  • How much is inexpensive?

    If it can't run off batteries, doesn't that disqualify cell phones as well?

  • hehe. yes you are absolutely right. cell phones do run on batteries :-)

    what I meant was that if I can track just the cellphone (maybe the gps or something) then people could use their own phone and the only thing I have to provide is the instructions.

    But prefer something else. How much is inexpensive? Well say about a dollar or two per item to track

  • Are you trying to track all 20 "sensors" at once? Or just one at a time?

    You might use a library like OpenCV to track red balls or something.

  • All 20 at once. (simply making drawings on the screen)

    Im not sure of the lightconditions in the audiance. That could be a problem with colortracking.

  • You're going to have issues no matter what, especially if you're limiting yourself to 1 dollar per device.

    You could also look into using a kinect to track crowd movements.

  • Yeah I usually use kinect sensor for this. But here since its a crowd I think I will have problem with kinect and need something more direct. For example cell phone.

    Okey, say 2 dollar per device :-) I can go up a bit in price then

  • What I mean is, no matter what solution you come up with, you'll have to deal with uncertainties and "what ifs". You aren't going to find a solution that works perfectly in every environment.

    Want cheap? Go with a bunch of colored balls, and track them using OpenCV. Yes you'll have to deal with lighting, but that's what you get for wanting cheap.

    You could also use kinect, but like you said, it might be hard to pick out 20 people from a crowd. You might consider changing your requirements so that it responds to the crowd as a whole, not individuals.

    If you really want to track individuals and not worry about lighting, then it's not going to be cheap. Using wii remotes comes to mind, or Sphero.

  • cell phones could be tracked via WLAN triangulation, GPS inside a room won't work


    red balls.... should be pinned to the shoulder... no... would look strange....

  • PerPer
    edited February 2015

    cell phones could be tracked via WLAN triangulation

    Sounds as a good idea. Never used this before. Do you know any link where this technique is more described, how to use it for example through arduino.

    How to track positions of cell-phones in the room via WLAN and get the values into processing? If it even was possible to set a range (for example "track every availible wifi signal within 20 meters distance and get the position-values and send them to processing") it would be great thing!

  • I have no idea.

    you'd need an app on each cell phone to do this...

  • aha. okej. not enough just to find all availible wifi connections

Sign In or Register to comment.