Mario Claw

Designed for EECS 373 Fall '05 Final Project

by Eugene Pan and David Miller

Introduction

Our project idea involved the development of a vending machine-type game. The system consisted of the following components:

• Frame - constructed entirely by K'Nex pieces
• Claw - main component of design; involves the use of servos servos
• NES-8 Controller - used to control the movement of claw
• LCD Display - display of timers and game specifics

By integrating the components listed above, our goal was to create a relatively low-budget replica of a claw-type prize retrieval game found in malls and arcades. We wanted to create a system that exhibits the knowledge of embedded system we've obtained this semester. We made use of the Motorola 823 microprocessor to interface our Nintendo-8 controller with our frame and claw. In addition, we incorporated an LCD display to show a timer, directional-pad, and the game's system information. This required a complex hardware design as well as a combination of both assembly and C code. As you can see in our reference section, skills that we have integrated into our design include both the hardware and software areas of designs.

Each component that was used played an essential role in the project. For pictures and more information on individual components, please click on the hyperlinks above.

High Level Design

        Please click here for high level design description.

Member Task Distribution

        David Miller - software implementation of timers and LCD display

        Eugene Pan - integration of servos into claw design and construction of claw unit; hardware design for servos

        combined efforts - construction and optimization of frame unit and movement interrupt units (failed), research and implementation of NES-8 controller, complete hardware design

Hardware and Software Design

Please click here for design specs.

Results and Conclusions of Design

In general, our design worked the way we expected it to. However, some functionalities had to be removed from the design. For example, we had immense difficulties getting our automatic claw reset to work due to noise issues. This was an analog problem, and despite spending many hours of work on it, we were not able to resolve this issue. Another issue that caused a lot of problems was the LCD screen. We spent close to three days trying to figure out why our LCD screen would not initialize, only to discover that the screen we had in possession was damaged. This is key: CHECK WITH OTHER IDENTICAL COMPONENTS! IT MIGHT NOT BE YOUR FAULT. After replacing the damaged piece, our design started to function correctly.

Another problem came with the servos. We spent a lot of time trying to perfect the timers and comparators to generate an exact signal replica found in the timing diagram. This turned into a huge hardware issue, and caused problems within the entire schematic. The eventual fix was to generate a close approximation to the signal, and at the same time simplifying the logic. This is a better method to attacking the problem. Always check to see if exactness is a requirement.

Finally, one unresolved problem, in addition to our reset function, was accessing the second set of fonts for the LCD screen. We were limited to first set, and despite extensive research on all possible LCD types, were not able to free up the second set. This was purely for aesthetic value, but still proved to be a challenge. In the end, we arrived at the conclusion that the second font set may have only been available to other LCD models.

 The components we chose allowed us to generate most of the desired functionalities of the claw. The major movement controls could all be done through the hardware and the NES-8 controller. The remaining timers, LCD screen, and general game procedure was easily created through software. In conclusion, we believe that our project was a success. We did not require anymore processing power and completed the project successfully. However, we were disappointed in the fact that we were not able to integrate our automatic reset function. If we had more time, we may have been able to look into this analog problem and resolved it.

For an example, click here to view videos.

Media Files

Please click here for included media files.

Appendix

At this time, we do not have anything included in the appendix page.

Please click here for appendix.

References

Please click here for reference section.