Vii Video Game System

The Project

A video game system for kids in grades 7-10 with little to no soldering experience to build. The main console was driven by a Parallax Propeller microcontroller with a Serial EEPROM for boot code loading, and an SD card for game storage. On boot, the system presented a menu listing the games on the SD card, which could then be loaded into RAM.

Campers built both the main console board and the controller.

Design Constraints

  • Cost – The budget available per kit was very limited, so a strategy of low-cost components and the pursuit of donated parts was used.
  • Ease of Assembly – the kits were assembled by children with little to no soldering experience, so components had to be well-spaced, and traces difficult to sever.
  • Fun – both offering a good assortment of games, but also providing room for expansion on the console board (a second controller, headphone jack, keyboard and mouse ports, serial port) for those campers wishing to enhance their experience with the system.

My Role

  • Research into initial concept. Identified components required and what work would be required to implement the system. Included research into using accelerometers for a motion-sensitive controller, later abandoned.
  • Circuit Design and Board Layout, with an eye towards ease of assembly
  • Troubleshooting, both of the initial design and of boards completed by campers
  • Training and Documentation. Counsellors had to be trained in how to build the project – soldering, component insertion, desoldering, cleaning up messy work, repairing damaged traces / pads, etc. In addition, the design needed to be well-documented for easy reuse in future camps.
  • Support Hardware Concept, Design and Execution. Over the course of the project several key pieces of hardware were required to keep the project going smoothly, including a self-contained controller tester and an EEPROM programming adapter.

Lessons Learned

  • Ensuring Product Availability – At the last minute, the board had to be respun to account for our chosen SD card socket not being available. Ordering these months earlier would have been a wiser choice.
  • Well-defined feature sets – A motion sensor was initially discussed and was mentioned in the camp advertising, and thus had to be implemented. A proper solution involving an accelerometer was not possible due to assembly complexity and cost, so a less-reliable alternative had to be devised.
  • Designing for childrens’ kits – Despite efforts to prevent assembly issues, a wide variety of soldering problems were encountered. Some were unavoidable, due to ignorance of instructions, others could have been prevented by using larger pad sizes, trace widths and isolation widths. There were substantially fewer problems than in the previous year.
  • Lab Equipment – It is absolutely essential to have good-quality soldering irons. Cheaper models were purchased but had their tips disintegrating within a week, if not less. Slightly more expensive models were later purchased and worked exceptionally well.

Photos

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