Overview
For this project, my partner and I had to create a device that would set off alarms when a "copy jam" was triggered. The device had LEDs and light, sensitive switches, so whenever two light sources next to each other were interrupted, a buzzer would sound, an LED on the board would come on, and the motor would stop running. We also had to build a switch that would turn off the light and buzzer. Once the light paths were restored, the motor would begin to run again. This logic was developed by using the below truth table and logic circuit and downloading the circuit onto the programmable chip wired onto the board,
CIRCUITS
To help us build the device, we used the PLTW website as a reference. However, they were using some different parts than us, so the most helpful image in building our device was the body diagram of the programmable chip (pictured below.) Also pictured below are some reference images that describe how we wired the inputs to the chip and the motor around the logic chip and then to the programmable chip.
circuit questions:
a.) Why resistors? This limits the amount of voltage going from the imputs to the programmable chip, which decreases the chances of short-circuiting.
b.) What is the purpose of the combinational logic circuit? This is so the device knows when to detect a jam, when to turn the buzzer and LED on, and when to stop the motor. It also clears all these things so then the device will work normally.
c.)Why do we have a flip flop? The flip flop is so that the buzzer will continue to sound until a clear switch/button is pushed. The motor continues to run as soon as the light hits the sensors again, but the buzzer continues to go off until the clear switch is hit.
d.) LED goes off, but buzzer stays on. The LED will turn off as soon as the lights hit the sensors again, just as the motor will turn back on. However, the buzzer continues to go off until the clear switch is flipped. This is so the person knows there still could be a jam and are able to be certain that they have reset it.
b.) What is the purpose of the combinational logic circuit? This is so the device knows when to detect a jam, when to turn the buzzer and LED on, and when to stop the motor. It also clears all these things so then the device will work normally.
c.)Why do we have a flip flop? The flip flop is so that the buzzer will continue to sound until a clear switch/button is pushed. The motor continues to run as soon as the light hits the sensors again, but the buzzer continues to go off until the clear switch is hit.
d.) LED goes off, but buzzer stays on. The LED will turn off as soon as the lights hit the sensors again, just as the motor will turn back on. However, the buzzer continues to go off until the clear switch is flipped. This is so the person knows there still could be a jam and are able to be certain that they have reset it.
conclusion
This project incorporated many of our concepts and required us to use our knowledge of circuits, truth tables and logic expressions, and wiring. However, we had to build something other than a breadboard for this project, which was new. We also had to use different parts such as a buzzer and motor.
Somethings I learned doing this project is:
1.)Sometimes, breadboards don't want to power for some reason. Don't waste your time crying over it, just start fresh. Usually, it really isn't even the breadboard's fault (no matter how much we want it to be).
2.)Making multiple things happen at one time is challenging, but you are left with a rewarding feeling once you have accomplished your task. THINK about what you are trying to do and how to get there.
3.)I learned just how copiers jam, what happens internally and externally, and how it is solved. Our project is a small version of these principles.
Somethings I learned doing this project is:
1.)Sometimes, breadboards don't want to power for some reason. Don't waste your time crying over it, just start fresh. Usually, it really isn't even the breadboard's fault (no matter how much we want it to be).
2.)Making multiple things happen at one time is challenging, but you are left with a rewarding feeling once you have accomplished your task. THINK about what you are trying to do and how to get there.
3.)I learned just how copiers jam, what happens internally and externally, and how it is solved. Our project is a small version of these principles.