I am looking for a way to digitally identify playingcard-sized cards.
The only requirements are:
- ID-cards have to be as small as a regular playing card
Some stuff has to be printed on those cards so humans can read it
Cards can be put into a slot --> information is read from the card by the raspberry
Data read from the cards (by the hardware module) can be very small, like just a number
Has to be cheap!
It doesnt matter if the data is read optically or by some other technique