Overview
In this project, we were tasked at designing a logic circuit that will detect a paper jam in a copier. The design would then be implemented on the digital logic board's Field Programmable Gate Array.
Constraints
Use an external power supply between 6-9 volts
Use resistors
Jam signal connected to LEDs
Activate both an LED and an audio buzzer
3 inputs
Below are images of our Truth Table, Boolean Algebra, K-map, and Simplified Expression:
Constraints
Use an external power supply between 6-9 volts
Use resistors
Jam signal connected to LEDs
Activate both an LED and an audio buzzer
3 inputs
Below are images of our Truth Table, Boolean Algebra, K-map, and Simplified Expression:
Circuit Construction
Explanations and Functions of different parts:
The resistors are in the circuit in order to buffer any input changes so that there is not a flickering effect or unwanted random or accidental input. As my partner Tayyab puts it, it makes it so that "any unconnected inputs need to be tied to a logic 1 or 0 which can easily be done by the pull up resistors."
The purpose of using a combination logic circuit, which we have, is so that you can determine an output using different types of conditions which can affect each other condition in different ways. In this case, using combination allows us to detect when two sensors are lit next to each other, but only if the clear switch is off will the buzzer sound under any condition.
The reason we are using a "flipflop" is so this "printer" can be set or unset to keep producing a noise whenever there is a jam sensed by the light sensors for as long as it takes for the clear switch to be flipped again.
Lastly, the reason the LED goes off and the buzzer stays on is that the buzzer is wired so that is will stay buzzing forever once a jam has been sensed, and in a real world setting this makes sense since a jam detected in a printer will not get fixed by itself, and even if the sensors inside of the device no longer detect a jam, it is most likely still causing issues. The light goes off immediately once the jam is no longer sensed because it lets someone know the state of the sensors, and thus will always need to show the current state, not a past state.
The resistors are in the circuit in order to buffer any input changes so that there is not a flickering effect or unwanted random or accidental input. As my partner Tayyab puts it, it makes it so that "any unconnected inputs need to be tied to a logic 1 or 0 which can easily be done by the pull up resistors."
The purpose of using a combination logic circuit, which we have, is so that you can determine an output using different types of conditions which can affect each other condition in different ways. In this case, using combination allows us to detect when two sensors are lit next to each other, but only if the clear switch is off will the buzzer sound under any condition.
The reason we are using a "flipflop" is so this "printer" can be set or unset to keep producing a noise whenever there is a jam sensed by the light sensors for as long as it takes for the clear switch to be flipped again.
Lastly, the reason the LED goes off and the buzzer stays on is that the buzzer is wired so that is will stay buzzing forever once a jam has been sensed, and in a real world setting this makes sense since a jam detected in a printer will not get fixed by itself, and even if the sensors inside of the device no longer detect a jam, it is most likely still causing issues. The light goes off immediately once the jam is no longer sensed because it lets someone know the state of the sensors, and thus will always need to show the current state, not a past state.
Conclusion
This project was different than our past ones because it was the first time using a "flipflop" in a circuit, and the first time we've done unguided wiring outside of a breadboard or used light sensors in a circuit. From this project I learned how flipflops can be used in circuitry for everyday uses, such as a printer malfunction, how to wire using a 74LS74 logic chip, and how to wire using light sensors. I also didn't know what a "pull-up" resistor was before this.