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Please help... I'm seriously going insane (traffic light + pedestrian light + button)

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kiwisteffu

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this may sound like the most retarded question in the world EVER. but I was assigned a project to make a traffic light and a pedestrian traffic light... basically, if I wanted to cross the street I would push the button, and the pedestrian light would turn green, and the traffic light red.

how do you get buttons to work? Dx AHHH!!!!!!!!!!!!!!!!!!! i can get a traffic light up and working, that's easy, im just breaking my head in 500 pieces trying to figure out how you add a button in there for that specific function... please help Dx I SUCK at electronics, I've exhausted every person who i thought could help, and the diagrams on the internet don't all have that nifty little button I need to understand. x___x

I'M DYING!!!!!!!!!! :(
 
lawl, everyone's asked me the same thing... our traffic light is A LOT simpler than that... we aren't writing it in any code.. bscly we're using flowcharts, a truth table karnaugh maps... and then grabbing equations and creating a simulated circuit on electronics workbench :(

I'll try and getcha a screenshot of the circuit we've mounted (I don't have it, someone else does)... it works FINE, except the button should send the traffic light to a red light immediately after it's pushed and it doesn't.

how would that work though... I'm talking about the flow chart part of the project at least. xDDD; yes I know we're embarrassingly stupid. :(
 
Hard logic problem

OK, so you are doing a hard logic problem as opposed to a soft logic problem. You need to post your flow charts, and any equations from the K-maps. and what ever schematic you have. then we can show you what path to take to finish it.
normally a push button is a pull-up or pull-down circuit with a latch, such as a D-dflip-Flop. Then the latch would reset during the light change cycle using the preset and clear inputs.
 
alright... the thing is I'm not sure if these things are correct... I'm really new at this and not precisely good at it.

My traffic light would change back to red when a button is pressed... I'm assuming that button would be handled by one or two control variables (x, y?)

how wrong am I? oh dear god my head aches. I've spent days looking up stuff related to this on the internet and nothing seems to help...

i'm gonna try and work s'more based on the stuff I looked up and update the thread, but suggestions and tips are welcome. you're also welcome to make fun of me for being such an ignorant prick 8D; i hate being so clueless...

**broken link removed**

oops!! I forgot my diagram was in spanish. presiono stands for "press", while no presiono... means, do nothing, pretty much... I guess that drawing there follows the normal cycle of a traffic light, while also having the possiblity at the yellow and green light to have a button pressed which will send the traffic light back to red.
 
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You indicated that you had developed logic equations, generated K-maps, and built a working virtual circuit. Your circuit had a problem in that you were not able to implement a user push button. Those statements would indicate that your design was fairly well developed. I do not see any evidence of that claim. No one here is going to be the antagonist, or protagonist in your proposed psychodrama. if you are willing to submit an honest evaluation of your work to date, I believe several people would be willing to assist you. If not there is nothing we can do for you.
 
k, i just finished putting together an excel sheet which explains the logic of my circuit... phew.. I dont have a scanner hence why the graphic looks so horrible.

and it just sounds as though i'm not being taken seriously. anyway. I've also attached the 100385397th flow chart I've made. I'm not seeing how any of my work allows user input. to my knowledge, my control variables were supposed to handle that (x, y)... but i don't know. it's an excel spread sheet. truthtable2.xlsx - File Shared from Box.net - Free Online File Storage
**broken link removed**
I'm dead! it's too bad you can't know for sure if this works or not until i've put together a circuit...
 
I suggest some of this step
1. Evaluate all the elements involved
2. Define the outputs and the inputs
3. Make a truth table 0/1
4. Make a Karnauh map that fit the equation from the truth table
5. Build the simple logic diagram with the simple gate AND, OR, NAND, NOR, XAND, XOR,etc
 
huh, I updated the thread with posts with link to everything I did, but it's pending admin approval, anyway it's been a while since I posted those... anyway, I DO have a diagram made in circuit maker.

hang on while I figure out how I can link to mywork without having to wait a million years 8D

---

ok, since I don't wanna wait for a post to be approved, i'll show you guys a screenshot of what seems to be going wrong with the circuit...

How come my Q output on 3 of my JK flipflops isn't receiving a charge? this is what's messing up my traffic light. does that mean I have to start all over again?

how can I upload my LiveWire file right away?

**broken link removed**
 
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for starters look at the JK flip-flop (X). The Q and not-Q are shorted together, along with sw1. a number of other gate inputs are also involved. I suggest that you check your entire design for these types of errors. They usually occur when you move the parts around while setting the spacing or orientation. the connecting wires get tangled and they are not always easy to catch after you have been staring at it for a while. also make sure that all of the connections are made. Some times if you overshoot the connection the program will lay down the track but the overlap won't allow it to connect, and it will read as an open circuit.You might try making a separate attachment of this schematic to your post I think you will get a better result.
 
at the driver end of the lights you can play a bit, when the push button latch a flip-flop, stop the clock for all circuit (by passing the clock through AND gate), drive all lights through another input(force to red- may need driver end modification if not exsisting) same time make padestrian one green. use seperate counter to count enough time to keep it on and then reset the latched flip-flop. now the clock is enables to vehicle side. if you need the push button input to wait until one trafic side complete it sequence of time, you have to take state change and enable push button latch to active.
 
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