ME218A Project: The Price Is Right

 

Team Members: Andrew Fahrland, Kristina Babiarz, Josh Oechslin

 

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Overview

 

Team 8ís project was a spin-off version of the TV game show The Price Is right. The game consisted of two stages: a price-guessing stage and a wheel-spinning stage. In the first price-guessing stage, the user is presented with a household item whose price they must guess more than a randomly generated guess by the computer. If the player gets closer to the true price than the computerís guess, they proceed to the second half of the game. In the second half of the game, the player gets to spin the big wheel on the front of the game on which price divisions are printed. The player accumulates money by landing on certain positions on the wheel. The playerís goal is to get as close to $1.00 without going over. Again, the computer generates a random guess which the player must compete against to win. If the player wins both rounds, a motorized dispenser awards the player a gumball.

 

Price Guessing

 

The main interactions with the player during the price guessing stage are text printed to a LCD display, a rotary dial and a button. Game instructions as well as the item to be bid upon are displayed on the LCD screen. The player turns the dial to select a price and the current price is displayed in real-time on the LCD screen. When the player is happy with the price theyíve entered, they push the button on the front panel to enter their guess.

 

LCD Interaction

The LCD is controlled by 10 output bits on the C32: a register select line, an enable line and 8 data bits. Text is slowly scrolled across the screen by printing a letter at a time with a small delay between screen writes.

 

Button and Dial

The button is a simple SPST toggle switch which toggles state every time the button is pressed. The button output is hooked to an input port on the C32 whose state is polled by the codeís event checker. The dial is connected to a rotary potentiometer whose wiper is connected to one of the analog to digital converter ports on the C32. The dialís state is polled every 256 milliseconds when the price is being displayed on the screen.

 

Wheel Spinning

 

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If the player beats the computerís guess in the first stage, they go on to the wheel spinning stage. In this part of the game, the player gets to spin the wheel and try to get as close to $1.00 as possible. They must get closer to $1.00 than a randomly generated guess between 60 cents and a dollar by the computer. Sixteen price divisions on the front of the wheel range between 5 cents and 1 dollar. The wheelís position is tracked using an optical encoder as detailed here.

 

Swag Dispensing

 

If the player successfully beats both parts of the game, they are awarded a gumball by the gameís swag dispenser. The swag dispenser consists of a drum with a hole drilled in it that rotates under a reservoir of gumballs. When the hole points upward, a gumball falls in and is then dumped out when the drum rotates downwards. The drum is rotated by a gear motor and the dispenser was calibrated to reliably dispense a single gumball by adjusting the speed and duration of the motorís rotation.

 

Electronics

 

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A full schematic of the electronics package used to control the game is shown here.

 

Code

 

Our pseudocode and C code used to control the C32 is shown with full comments here.

 

Budget

 

Our budget is shown here.