Identification Technique

[Oliver Azren]

Hello,

I'm building a 20cm x 20cm table that is divided into cells, it has 4 rows and 4 columns.
There will be different external blocks that have numbers, each block can stand on a single cell, each block has different number.

each cell on the table should be able to detect and recognize different blocks, so that i could know which block on which cell ...

The problem is, what technique can I ably inside the table/matrix to detect and identify these blocks so that, for instance, i know that the block with the number 5 is on the 3rd cell.

I'm thinking of NFC technology where each cell will has NFC reader and inside each block will be NFC tag but it's not practical due to the size and cost of the reader. any suggestions (it could be wired or wireless technique )?

Thank you in advance,

 

[BradtheRad]

Would this work?

Each cell has a photosensor pointing upward. It can detect if a block is on it.

If the cell is dark, have it emit a brief audio tone. The tone tells all blocks to send out a series of flashes.

The number of flashes identifies the block. (Or any code of your choosing.) The cell sees only the flashes from the block which occupies it.

 

[andre_luis]

Due to it relatively small size, you could think about the possibility of using an imaging system, especially if the numbers are printed in the same orientation.

Unfortunately, a recognition system like this would have to be developed or adapted tailored to your application. A model that could be used in the first stage of the project would be the algorithms used for identification of automobile license plates.

 

[chuckey]

Make you table clear and have a bar code reader underneath. As it scans you can work out the XY coordinates of each bar code number.
Frank