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March 15, 2006

Results and Reflections

Although it came down to the wire, we were able to align all the components just right, achieving our first objective of successfully dealing cards. Out of an inserted deck of 52 cards, we were able to deal all but 10 cards, a fairly low failure rate, given the complexity and time constraints of the project.

We were also able to achieve our second objective of reading the cards, although with limited success. We were only able to accurately read approximately 1 out of every 7 or 8 cards. This seemed to be a result of the dealer spitting out the cards too quickly for the scanner to read the barcode. Additionally, given the limitations of our PC-104 stack inputs and the ps/2 scanners we purchased, we were not able to interface the two, but had to output the card value to another computer and monitor.

Finally, we were able to achieve our third objective of moving the cart into different dealing positions with consistent success. After dealing a card in each direction, the cart moved to the next space without a single failure.

Our fourth objective, of lowest priority, was to flip cards as they were dealt. We were unable to address this task in our programming, although we were able to flip cards by activating the solenoids manually. We did not have time to fine-tune the timing between the card sliding off the deck, being scanned, and then being flipped before it left the dealer.

Although we were able to confidently declare our project a success, given that we achieved our three primary objectives, there are a number of improvements and changes that we would make in either continuing or redoing the project.

The biggest challenge we faced throughout the project was balancing the complexity of our mechanisms with the time constraints of the quarter. There were a number of changes we would have liked to make, had the project run a few weeks longer.

For example, we recognized early on that the springs used to lift the deck would have wide variance in applied force, depending on how many cards were in the bin. An entire deck compressed the springs by nearly 50%, causing the cards to bind and sometimes prevent their exit from the dealer. We would have liked to incorporate constant-force springs into the dealer, which would have applied the same force, regardless of how many cards were in the bin. We decided to stick with the standard compression springs only because the design was already developed and time was quickly growing short.

Another example is in the dealing wheel. We initially planned on using a belt with 2 sprockets that ran the length of the cards, and would pull each card entirely off the deck. However, once we began fabrication, we decided to experiment with a wheel instead, which was much easier and quicker to fabricate in the machine shop. By the time we realized that this was a more difficult solution to implement, we did not have enough time to order the necessary components and re-machine parts. We were able to make our single wheel work relatively consistently, but we believe a belt and sprocket system would have been even more consistent. Additionally, the belt would have allowed us to pull the card out more slowly, allowing the scanner more time to accurately read each card. As it was, we had to spin the wheel fast enough to simply accelerate each card enough for it to overcome the friction forces. This meant the cards flew out of the dealer, often distances up to 3 feet, and often moved too quickly for the scanner to read.

Although we were not able to accomplish everything we had originally outlined in the initial project conception, our ambitious objectives motivated us to develop the very best dealer we could in the short time we had. From here, our initial vision of an automated blackjack dealer and player is very attainable, and would only require the implementation of the card-flipping solenoids, a more consistent dealing mechanism using a belt and sprockets, and some additional programming.

We very much enjoyed working on this project and in this class, despite the difficulties and long hours, and we only wish we had more time to accomplish everything we wanted.