[HELP][RENEW]Traffic Lights

Thread Starter

nubpwn3r

Joined Oct 15, 2015
15
soo after some help from you guys I have made the project and it was working smoothly
we showed it to our professor but he was not pleased, he recommended that we redo it so that GREEN HAS A COUNT OF AT LEAST 10, RED ALSO 10 AND YELLOW 3.

the seven segment display should behave so that when for example: Green counts down from 10 to 1, after 1, it resets back for the next duration of the next light which is yellow with a count of 2, then comes red after the 1 count of yellow

so the 7 segment display should show something like this:
Green: 10 9 8.......2 1 ~> Yellow: 2 1 ~> Red: 10 9...... 2 1 ~> Green.... cycle back

Our current project is a traffic light with a countdown of 9 to 0 Green count of 4. Red count of 4. and yellow count of 2.
Using 74192 as the clock 0 to 9. connected to 7447 and is then conneted to 7 segment display
• For the lights red green yellow, we used CD4017BE decade counter and each output is connected to a LED

our professors recomendation is found above in bold:

thus we need to use two seven segments for the 2 digit count for red and green LED

-my problem is how do i do that im currently thinking of JK F/F as a 5 bit modified countdown BUT i think its impossible to put it into a 7 segment decoder with 5 bits

-another thing i can think of is using multiplexers, but the only available multiplexer here is 4 to 1

other than these things, i am clueless

need help pls


Edit1: added condition i forgot to post awhile back about the 7 segment behavior
 
Last edited:

GopherT

Joined Nov 23, 2012
8,012
soo after some help from you guys I have made the project and it was working smoothly
we showed it to our professor but he was not pleased, he recommended that we redo it so that GREEN HAS A COUNT OF AT LEAST 10, RED ALSO 10 AND YELLOW 3.

Our current project is a traffic light with a countdown of 9 to 0 Green count of 4. Red count of 4. and yellow count of 2.
Using 74192 as the clock 0 to 9. connected to 7447 and is then conneted to 7 segment display
• For the lights red green yellow, we used CD4017BE decade counter and each output is connected to a LED

our professors recomendation is found above in bold:

thus we need to use two seven segments for the 2 digit count for red and green LED

-my problem is how do i do that im currently thinking of JK F/F as a 5 bit modified countdown BUT i think its impossible to put it into a 7 segment decoder with 5 bits

-another thing i can think of is using multiplexers, but the only available multiplexer here is 4 to 1

other than these things, i am clueless

need help pls

There are chips like the CD4510 that can be cascaded together. The clock pulse goes into the first one (ones digit) and that puts out a binary-converted-decimal (BCD) output. After a binary 9, the count rolls over to 0 AND, there is a special output that sends a clock pulse out to the next cD4510 in the cascade.

You can put together as you want. The good news, you can count UP or Down.

Google datasheet - CD4510.

The output of each of these chips can then go to a CD4511 (decodes the BCD output to a 7-seg display) which drive a 7-segment LED
 

Thread Starter

nubpwn3r

Joined Oct 15, 2015
15
There are chips like the CD4510 that can be cascaded together. The clock pulse goes into the first one (ones digit) and that puts out a binary-converted-decimal (BCD) output. After a binary 9, the count rolls over to 0 AND, there is a special output that sends a clock pulse out to the next cD4510 in the cascade.

You can put together as you want. The good news, you can count UP or Down.

Google datasheet - CD4510.

The output of each of these chips can then go to a CD4511 (decodes the BCD output to a 7-seg display) which drive a 7-segment LED

ty for urgent reply really appreciated it
ahhhh i get the point but that would only make a bigger scale of our project

the seven segment display should behave so that when for example: Green counts down from 10 to 1, after 1, it resets back for the next duration of the next light which is yellow with a count of 2, then comes red after the 1 count of yellow

so the 7 segment display should show something like this:
Green: 10 9 8.......2 1 ~> Yellow: 2 1 ~> Red: 10 9...... 2 1 ~> Green.... cycle back

im a bit at fault for forgeting to include that condition in my post, gonna make an edit right away
 

djsfantasi

Joined Apr 11, 2010
5,705
Are you sure the count has to be 10 to 1? Counting from 9 to 0 is also a ten count. Only needs one 7 segment display.
Per GopherT's post, the 4510 can be configured to count down. Then a decade counter can count to which color should be displayed. Look up the data sheet for a 4017.
 

Thread Starter

nubpwn3r

Joined Oct 15, 2015
15
Are you sure the count has to be 10 to 1? Counting from 9 to 0 is also a ten count. Only needs one 7 segment display.
Per GopherT's post, the 4510 can be configured to count down. Then a decade counter can count to which color should be displayed. Look up the data sheet for a 4017.
what i am trying to say is that the countdown for the light green / red should be 2 digits sooo it should be at least 10 which is a two digit number
other details can be found in my previous posts.

that was our first design for the traffic light, a 9 to 0 count but yea professor made revision sad
 
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