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Decisions Module Help


The Decisions Module

    The Decisions Module is made up of elements which each have input terminals, output terminals, or both. The input sensor elements along the left side only have output terminals, where they output to you what is going on in the "outside world." The logic gates in center take inputs and generate outputs by performing the boolean operations NOT, AND, and OR. The output devices along the right side have only input terminals, and what you input to them determines what they output to the outside world.
    To connect two terminals (the small gray circles) with a "wire", drag from an element's output terminal to an element's input terminal. Output from the first element now becomes the input to the second element. To delete a wire, you just have to shift-click on it. Here is an example:


    Here a wire has been drawn between the push switch and the lamp. The lamp will now light up whenever the mouse is down on the push switch.
    Here is an example of using the OR logic gate. If the temperature sensor has been heated up OR the mouse is down on the push switch, the lamp will turn on:


    In the example below, a NOT gate and an AND gate are used, and the output from the NOT gate goes back across the board to the input terminal of the AND gate. For the buzzer to sound, the light sensor must be NOT reporting any light, AND the slide switch must in the "on" or "1" position.


Here are some tips about using the board:
  • The slide switch can be operated simply by clicking on it.
  • The light sensor will report light as long as it is not "blocked" by putting the cursor in front of it.
  • The temperature sensor can be "heated up" by moving the cursor back and forth across it. It will then "cool down" after a few seconds.
  • The push switch can be operated by holding the mouse down on it or with the space bar.
  • To use the buzzer, make sure the system volume on your computer is turned up high enough that you can hear it, but not all the way, or the sound will be very loud. The buzzer sound is made by repeating a small sound clip over and over again, so it may not always perform reliably.
  • You can change the color that new wires are created in by clicking repeatedly on the small color box in the lower-right corner of board.
  • In general, if two wires connect to the same input terminal, their values will be "OR"ed.


Click here to return to the main Decisions Module page.