Double Down

This entry contains the continuation of our project propsal, found here, and continuing from here.

The following is taken from our project proposal:

2 The player

Figure 3: Card’s Barcode

For our device to play any number of card games, it will need to know what cards it deals itself and sometimes which cards are dealt to the player(s). After considering several methods we agreed upon a barcode and phototransistor system, as it would be the simplest to implement in our design and doesn’t require metal contacts or stickers on the cards so that they remain slick for easier dealing.

2.1 Card Recognition

Using a template, a binary barcode will drawn on each card in opposite corners. The barcode will be composed of two parallel 6-bit binary numbers. The first set of lines will be all black and will act as the clock cycle for triggering the reading of the other set of lines next to it. The second set is then the one holding a binary number 1-52 for each card in a deck.

Figure 4: Methods for Sensing Barcode

An LED will light up the underside of the card and either one or two phototransistors will detect if the card reflects or absorbs the light. Two phototransistors can be used as digital inputs for reading the two lines, or one phototransistor can be used as an analog output to differentiate between no lines, one line, or two.

Figure 5: Sensor Position

The phototransistors and LED will be positioned at both outputs of the deck housing and will read the barcode as the card is dispensed. They can either be under a clear ramp that the cards slide down or in a recess of an opaque ramp.