Madame Lucy
The Amazing Fortune-Telling Goose
Natalie Levinson '09 & Christina Miller '08

The Coin Sensor

Inserting a coin into the box started Lucy's fortune telling routine.

Process:

Construction
We constructed the box with scraps of cardboard and duct tape, then covered it in fabric and construction paper. A reflectance sensor is taped on the interior of the box, facing the coin slit. When a coin passes through the slit, the reflectance sensor detects it and the fortune-telling process begins.

The inside of the coin box showing the reflectance sensor and the sloped bottom.

Code
The sensor was set up with auto-thresholding to ensure it would work regardless of any change in light environment.

Here are the sections of our code that ran the coin sensor:

menu 1 [initialize]
menu 2 [accept-coin]

global [coin-threshold change-coin shiny egg-dropped?]

to initialize
            setcoin-threshold (coin-sensor)
            setchange-coin 20
            setshiny 110
end

to accept-coin
            loop [
            waituntil [not coin?]
            waituntil [coin?]
            wait 10
            tell-fortune
            ]
end

to coin?
            ifelse ((coin-threshold - coin-sensor) > change-coin)
            [output 1]
            [output 0]
end

to coin-sensor
            output sensor 0
end