Project report requirements:
o A brief description of the design process you used to obtain the circuits. Be sure to point
out why you chose a particular design, along with the steps you took to minimize the
amount of hardware required. This includes
State diagram
State reduction
Final (reduced) state table
o Include all design elements, such as truth tables, state diagrams, tables, etc,
o Test the device in the simulator. Include a test plan:
Include your secret code for verification
Example inputs, expected outputs and what happened when you tested.
Descriptions, along with a detailed explanation of what simulations you did, what
they show, to demonstrate that the circuit works properly under “all” circumstances.
NOTE that all Logisim implementations must meet all labeling requirements, as established at the
start of the semester (see Lab 1)
Project Description
There are many security and access control devices on the market that attempt to prevent
unauthorized access to secured areas. One such device is a key-pad based device. To unlock the
door, you must enter a secret decimal code. For example, say a device accepts a 4-digit decimal
code, 1234. The device will unlock the door when “1234” is entered, but it will not unlock if “123”
or “123411” is entered.
For your final project, you are to design an access control system based on a sequence of 6 bits
that accepts a 1-bit at a time, either 0 or 1. This could be implemented with a 2-button keypad (o
and 1), used to enter the binary code.
A second input functions as the Enter key, which ends the key code entry. As the key is entered,
the device outputs Enter = 0 until the input sequence terminates. If the input sequence matches the
access code, then output Enter =1 (for example LED lights up), which will unlock the door in a
full implementation. The secret code is preset: choose your own code (see below).
After two unsuccessful attempts (i.e. the secret code was not matched), the system shuts down and
won’t accept any more bits, and an alarm is triggered. Thus, your circuit has a second output
Alarm, which is set to 1 after two unsuccessful attempts.
Extra credit: Add a reset to the system that presumably only the owner could control: when the
reset key is inserted, the system is again enabled and can accept bits again. You can code the reset
as either 0 (no key) or 1 (key inserted) for this project.
Secret code:
Each of you has their very own secret code: no 2 people in the class can have the same
code
Your code can NOT be a simple sequence of all 1s or all 0s, and must contain a minimum
of 2 ones and 2 zeroes
