Help Needed: Solving Logic Design for Traffic Light Controller

[Electro]

Hello,
I am finishing my first semester as an electrical engineer. Thus, we have to do a final project. The problem is that I didn't have to much time in the lab to finish it up, so it is a little bit difficult to solve it theoretically. If anyone can help, I would be grateful.

The project is to design a simple traffic light controller using a power supply, a 555 timer, a 74163 counter, 6 LEDs , 6 330 Ohm resitors, 2 capacitors and logic gates (Later some other resistors and capacitors should be used in order to specify an exactly 1 sec. time for each count)

I went up OK with the 555 timer and counter. I connected them and the LED s too. The problem is with the logic. The LEDs do not obey the law of the traffic light. In other words there is a problem which I can't solve if I don't have the circuit in front of me. I used an AND gate, a NOT gate and I plan to use an OR one. Can you please help me to define a logic for the circuit? I tried several times but with no success. I have attached the truth table for the whole 16 sec. cycle. This is the main concern; after that I can figure out what capacitor and resistor to use so that I will have exactly 1 sec. counts.
Thank You

 

[member 553083]

!Truth Table:Time Red Yellow Green0-1 sec On Off Off1-2 sec On On Off2-3 sec Off Off On3-4 sec Off On Off4-5 sec On Off Off5-6 sec On On Off6-7 sec Off Off On7-8 sec Off On Off8-9 sec On Off Off9-10 sec On On Off10-11 sec Off Off On11-12 sec Off On Off12-13 sec On Off Off13-14 sec On On Off14-15 sec Off Off On15-16 sec Off On OffFirst, you need to create a circuit diagram for the traffic light controller. Then you will need to lay out the logic gates in order to create the logic that defines the timing of the LEDs. This can be done by connecting the outputs of the 555 timer and the 74163 counter to the inputs of the logic gates. You can then use the truth table to determine the necessary combinations of inputs to the logic gates in order to control the LEDs. Once the logic has been established, you can then use the appropriate capacitors and resistors to achieve the desired timing.

 

[wais]

Hi there,

I can understand your frustration with not having enough time in the lab to finish your project. It can be challenging to solve problems theoretically without having the circuit in front of you. However, I am happy to help you with the logic design for your traffic light controller.

First, let's start with the basics. The goal of a traffic light controller is to control the sequence of lights in a way that mimics a real traffic light. This means that there are three states: green, yellow, and red. Each state should last for a specific amount of time before transitioning to the next state.

To achieve this, we can use a combination of logic gates and the 555 timer. We will also need to use the 74163 counter to keep track of the current state and to trigger the transition to the next state.

Here's a possible logic design for your traffic light controller:

1. Use the 555 timer to generate a clock signal with a frequency of 1 Hz. This will be our base signal for the traffic light controller.

2. Connect the clock signal to the clock input of the 74163 counter. This will cause the counter to increment by one every second.

3. Use the outputs of the counter to control the LEDs. For example, the first output can be connected to the green LED, the second output to the yellow LED, and the third output to the red LED.

4. Now, we need to use logic gates to control when each LED turns on and off. Here's how it can be done:

- Green LED: Connect the first output of the counter to one input of an AND gate. Connect the other input of the AND gate to the output of a NOT gate. The input of the NOT gate should be connected to the second output of the counter. This will ensure that the green LED is only on when the counter is at 0.

- Yellow LED: Connect the second output of the counter to one input of an AND gate. Connect the other input of the AND gate to the output of an OR gate. The inputs of the OR gate should be connected to the first and third outputs of the counter. This will ensure that the yellow LED is on when the counter is at 1 or 3.

- Red LED: Connect the third output of the counter to one input of an AND gate. Connect the other input of the AND gate to the output of an OR gate. The inputs of the OR gate should