Recognize active objects with a capacitive touch screen display

Question

I'm trying to develop an app that can recognize an active object (for example: a memory) that touch the smartphone display. Before I start to develop I've to know if there's any objects that my touch screen display can recognize? Which device can be recognizable by a smartphone display? I'm interested to know that for iPhone or for Android phone. I found this app and you can see that with a card I can interact with a mobile device, now I'm asking you if anyone know how to do this kind of app with an iPhone or with an Android phone. Does anyone knows how to do that? There's a library (iOS or Android) to recognize object that I put over the display?

Answer 1

volumique is the company that develops the monopoly card technology that you are talking about. However I will suggest two things.

1. For Android devices you can use NFC. Its kind of what you are doing right now but you just need to bring your object closer to the screen, no need to actually touch it.
2. For iOS, there is no NFC or RFID technology available. However you can develop a hardware which has active capacitors arranged in a pattern over it so when you bring your device closer to the iOS screen, the touch controller should recognize the pattern of the capacitors and report this to the main controller which can do recognition of the object with the help of your code. basically capacitive touch screens used in iPhones are just an array of capacitors arranged in a grid pattern. So when you touch using your finger, you change the capacitance of one or two capacitors and then the controller finds out the location of the change. However if you change the capacitance of say 5 6 sensors at the same time, in a particular order like in a pentagon, then you can write software for your controller that if the location of the sensors whose capacitance has been changed by this external object form the shape of a pentagon, then show the viewer that it is a 5 $ card (just an example). This is one way I can think of doing this.

Thanks