Up/Down Guesing Game PDF Print E-mail
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Thursday, 11 February 2010 15:51

This was a project I created circa 2008 in college for an intro to digital logic course. The game is based around a 555 timer. To play you would...

  1. Flip the switch to the "New Number" position. This would cause the 555 begin incrementing the first 7490 counter (ones digit). The output of bits 0 and 3 are ANDed and drive the second 7490 counter (tens digit). The counters are falling edge sensitive. So when bits 0 and 3 are set (Decimal 9) the AND gate will be active. When the counter rolls back to zero, the AND gate will fall and increment the tens digit. This way I have two counters generating the numbers from 0-99.
  2. The outputs from the decade counters are split two ways, to a set of comparators (we'll see those next) and to a set of multiplexors. When the switch is in the "New Number" position, the multiplexors will display the output of the decade counters. This way the user can see the game generating a new number. The 555 is running fast enough so that the player can not read the display. (This would defeat the purpose of the game)
  3. Flip the switch to the "play" position. The 555 timer will stop counting and the display will now show the number the player has selected on the rotary encoders. The player can now adjust the rotary encoders to guess a number. The player will then press the "guess" button to see if the number they guessed is higher / lower / equal to the generated number. This is accomplished by comparing the generated number and the users guess with two 7485 comparators.
  4. Player can adjust rotary knobs and try to guess a new number until the "Win" LED illuminates.


Last Updated on Saturday, 20 April 2013 14:03