Beginning
- In this project we had to create a circuit that would mimic a copier being jammed. The three photo sensors were paired with three lamps. If an object broke two adjacent light beams at the same time then a logic 1 is outputted. When two adjacent beams are not broken at the same time then a logic 0 is outputted. The paper should pass through without breaking two beams at once but if it does an alarm will go off.
- Some constraints were having a time limit, limited material usage and we could only work in partners.
Circuits
Explanation of parts and functions
- The pins one, two and three are what connect to the phototransistor setup. For the breadboarding, resistors were needed for the Fishertech kit and the PLD chips. The resistors were used so the circuit would not get shorted out by too much too much voltage.
- The purpose of the combination logic circuit is so the LED and Buzzer go off when they're supposed to. The logic will output a 1 when two adjacent phototransistors are being blocked by paper. This then goes into a clock signal of a D Flip-Flop and it stays on until cleared.
- The Flip-Flop is implemented so the signal that goes through goes into the CLK of the Flip-flop, which is set to toggle. However, once a signal goes through, and a 1 is the output from the Flip-Flop, it will not turn off until cleared. This is for the buzzer, as it is not supposed to stop buzzing until a button (CLR) is reset.
- The LED is implemented after the combinational logic. This means that whenever the logic outputs a 1, the light will be on and when the logic outputs a 0 but the light is off. This differs for the buzzer, which is after the Flip-Flop, since it will stay on until it is cleared.
Conclusion
This project was different from the ones we completed up to now since we used AOI logic gates plus sensors instead of switches, buttons and clocks. In this project I learned how to use AOI logic gates as inputs and how to use other devices as switches.