Looking for a suitable input method to identify various obstacles.

Hello there!

I am looking for a suitable input method for the task seen in the attached picture.

The “sensor” should regognize different small obstacles (on very close range or contact ), which have some kind of “readable thing” on them, so the arduino board (arduino uno) gets a specific input. But there are other limitations too:

  • the system must be affordable and small
  • the “readable thing” on the obstacles must be easy and cheap to produce (for example a barcode)

The obvious solution would be a barcode scanner and there are some tutorials around, but I was hoping for something simpler.
For example to equip each obstacle with a different resistor/potentiometer and connect it to an analog input of the arduino, so the input would depend on the incoming voltage. Would that be suitable or are there better solutions?

I’m very interested in your opinion and ideas.
Greetings,
Lucas

Would that be suitable or are there better solutions?

RFID reader and adhesive tags on the "obstacles"? Probably cheaper than barcode reader and very easy wiring. At least it fulfills your "specification".

That would be a possibilty and a very elegant one, too (: .
The mysterious "obstacles" are Tabletop-figures. So I need at least 40 RFID-Chips and a reader/writer module. I just looked for some of those on ebay and they aren't very expensive. So I will do some searching on google to see if it's suitable.

Thank you!

So I need at least 40 RFID-Chips and a reader/writer module. I just looked for some of those on ebay and they aren't very expensive. So I will do some searching on google to see if it's suitable.

40? In your picture you had 4 of them.

In what distance will these figures be when you want to identify them? RFID antennas of reasonable sizes reach about 5-10cm.

pylon:
40? In your picture you had 4 of them.

In what distance will these figures be when you want to identify them? RFID antennas of reasonable sizes reach about 5-10cm.

I was too lazy to draw 40 squares. The distance doesn't really matter. I wanted to place the figures directly over the sensor (one at a time). 5-10 centimeters would defintly be enough.

But what about other solutions? Like a color sensor for example! I could glue colored paper under the figures to identify them.

Like a color sensor for example! I could glue colored paper under the figures to identify them.

you will not be able to generate and read 40 different colours.

Grumpy_Mike:
you will not be able to generate and read 40 different colours.

That's true. But in this case I don't need 40. Because there are figures with the same "attributes". So I would have a group of figures with the same color on the bottom. But the sensor must idenify at least 10-15 different colors without difficulties.

This module should be able to manage that task, right?

This module should be able to manage that task, right?

Well it is worth a try but it might be harder than you think.

I have been using the Lego colour sensor in the EV3 set and that is quite good but that is restricted to 7 colours only. It has an illumination LED as well, I suppose you could add one to that board.