Tollbooth
Explanation
Inputs- The tollbooth has 4 inputs which are represented by the open switch, closed switch, open limit and closed limit. These inputs control the actions taken by the tollbooth itself.
Outputs- The tollbooth also has 4 outputs which are; open meter, closed meter, open gate, closed gate. These outputs show whether the tollbooth is open, closed or moving in one direction.
States- There are only two states which are Qa and Qb which represent Da and Db
Outputs- The tollbooth also has 4 outputs which are; open meter, closed meter, open gate, closed gate. These outputs show whether the tollbooth is open, closed or moving in one direction.
States- There are only two states which are Qa and Qb which represent Da and Db
Description of Process
The process we are simulating is the physical process taken out by the tollbooth machine.
Example;
Qa Qb
0 0 The gate is closed
0 1 The gate is opening
1 0 The gate is open
1 1 The gate is closing
Example;
Qa Qb
0 0 The gate is closed
0 1 The gate is opening
1 0 The gate is open
1 1 The gate is closing
Conclusion
During this project our group was asked to create a machine that represented the actions taken out by a tollbooth on a day to day basis. In this design we are asked to use PLD to create a functioning prototype that has four inputs and four outputs. The projects finished product is another representation of a state machine which is the topic we are currently learning about. A state machine is a machine that performs a continuous set of actions based off of the push of a button or the flick of a switch. During this project we had few mistakes but instead had multiple instances during which we would complete an objective and not know the next step to take. The easiest part however was without a doubt the building of the machine while the hardest was probably understanding the schematics. The difference in this project when compared to the previous ones is the fact that we combined circuitry and robotics instead of just building the circuit in multi-sim. The project itself was more difficult to understand than create but once we understood everything that was supposed to happen we had little trouble. First when you press the Open Switch you send a logic signal of one to the motor which causes it to open the gate. Then when you press the open limit switch it sends a signal to the LED that tells you the gate is open. When you press the close switch it sends a signal of one to the motor as well and close the gate. These steps help explain the circuit and describe what is supposed to happen which allowed us to understand what we needed to create in order to create a working system. This project was much easier than those at the beginning of the year just because our understanding was better.