1. Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.
    Dismiss Notice

please help with my crossroad traffic light project...

Discussion in 'Homework Help' started by D@rkL0rd, Jun 22, 2014.

  1. DerStrom8

    DerStrom8 Super Moderator Most Helpful Member

    Joined:
    Aug 9, 2010
    Messages:
    5,484
    Likes:
    503
    Location:
    Vermont (GMT-5:00)
    There is not much technical language there, if you read past the sophisticated way of saying it. All it's saying is the following:

    1. The 4017 has 10 outputs that you cycle through
    2. The input pins include a clock, a reset, and an inhibit
    3. The output transitions to the next on the positive clock signal change, assuming Inhibit is low (0v). If the inhibit signal is high (5v), however, it does nothing.
    4. Connecting the Reset pin to +V resets the output back to the first one
    5. A carry-out pin allows multiple 4017s to be "cascaded" one right after another, to allow more outputs to be controlled by one clock.
    Now that's not too complicated, is it? Just read the text carefully, and don't be daunted by the fancy speech :p

    Regards,
    Matt
     
  2. D@rkL0rd

    D@rkL0rd Member

    Joined:
    Jun 22, 2014
    Messages:
    70
    Likes:
    0
    thnx
     
  3. D@rkL0rd

    D@rkL0rd Member

    Joined:
    Jun 22, 2014
    Messages:
    70
    Likes:
    0
    i know i just a newbie here...but never mind i understood it...now i know that i need a high time pulse for .5 sec and low time pulse for 0.5...thnx for your time...
     
  4. dave

    Dave New Member

    Joined:
    Jan 12, 1997
    Messages:
    -
    Likes:
    0


     
  5. D@rkL0rd

    D@rkL0rd Member

    Joined:
    Jun 22, 2014
    Messages:
    70
    Likes:
    0

    thnx...can you please telll what the inhibit pin does i am really not clear on that... and when we connect reset to +V it rests output after full cycle of ten pins or after first pin and moves in a loop...
     
  6. DerStrom8

    DerStrom8 Super Moderator Most Helpful Member

    Joined:
    Aug 9, 2010
    Messages:
    5,484
    Likes:
    503
    Location:
    Vermont (GMT-5:00)
    When high, the inhibit pin prevents the output from advancing even if it receives a clock signal.

    Connecting reset to +V will reset it back to the first output regardless of which output is set at that particular moment. The way my circuit is set up in the simulation video, I have the last output connected to reset. This way, it will reset whenever the last output is reached, allowing it to restart the loop. You can also connect the reset pin to +V at any time (perhaps via a push-button) to manually reset the chip to the first output.
     
    • Thanks Thanks x 1
  7. audioguru

    audioguru Well-Known Member Most Helpful Member

    Joined:
    Mar 16, 2004
    Messages:
    32,444
    Likes:
    936
    Location:
    Canada, of course!
    NO you don't need the clock to have a "high time pulse for 0.5 sec and low time pulse for 0.5 sec". You just need the clock to go high each second so the timing can be high for 0.9 sec and low for 0.1 sec., or high for 0.7 sec and low for 0.3 sec.
    It will even advance each second if the clock was high for 0.1 sec and low for 0.9 sec but it is difficult to get a 555 oscillator to Doo Dat.
     
    • Thanks Thanks x 1
  8. D@rkL0rd

    D@rkL0rd Member

    Joined:
    Jun 22, 2014
    Messages:
    70
    Likes:
    0
    thnx ...
     
  9. D@rkL0rd

    D@rkL0rd Member

    Joined:
    Jun 22, 2014
    Messages:
    70
    Likes:
    0
    thnx
     
  10. alec_t

    alec_t Well-Known Member Most Helpful Member

    Joined:
    Jul 10, 2011
    Messages:
    9,254
    Likes:
    1,218
    Location:
    Cardiff, Wales
    Post deleted
     
  11. D@rkL0rd

    D@rkL0rd Member

    Joined:
    Jun 22, 2014
    Messages:
    70
    Likes:
    0
    well i finally got the required pulse from the timer ....but now in the counter the pin 0 is not going high in the first loop it goes high int he second loop...please help
     

    Attached Files:

  12. DerStrom8

    DerStrom8 Super Moderator Most Helpful Member

    Joined:
    Aug 9, 2010
    Messages:
    5,484
    Likes:
    503
    Location:
    Vermont (GMT-5:00)
    First of all you should connect the EN pin to ground. Right now you aren't even enabling the 4017!
     
  13. D@rkL0rd

    D@rkL0rd Member

    Joined:
    Jun 22, 2014
    Messages:
    70
    Likes:
    0
    so how is it oscillating and connecting it also doesnt solve the problem...
     
  14. DerStrom8

    DerStrom8 Super Moderator Most Helpful Member

    Joined:
    Aug 9, 2010
    Messages:
    5,484
    Likes:
    503
    Location:
    Vermont (GMT-5:00)
    I guess I misunderstood the question. You should still have it connected to ground, and you should have Q9 connected to reset so that it loops without extra delays. This may solve the issue with the LED not turning on "on the first loop". It IS turning on in the first loop, but there is an extra delay when Q9 is on and none of the other pins are. That's why you need to reset the 4017 when Q9 is reached (meaning the light cycle is complete).
     
  15. D@rkL0rd

    D@rkL0rd Member

    Joined:
    Jun 22, 2014
    Messages:
    70
    Likes:
    0
    why isnt the led turning on what am i doing wrong here...
     
  16. DerStrom8

    DerStrom8 Super Moderator Most Helpful Member

    Joined:
    Aug 9, 2010
    Messages:
    5,484
    Likes:
    503
    Location:
    Vermont (GMT-5:00)
    Didn't you read my post? Connect Q9 to Reset and try again.
     
  17. D@rkL0rd

    D@rkL0rd Member

    Joined:
    Jun 22, 2014
    Messages:
    70
    Likes:
    0
    i did connect it but after taht the 9 pin is not going high its just starting from 1 ... i need all ten pins to go high for 1 sec each...i have uploaded the logic table for which i need to create the circuit...
     

    Attached Files:

    • 4.png
      4.png
      File size:
      957.5 KB
      Views:
      136
    • r.png
      r.png
      File size:
      702.6 KB
      Views:
      151
  18. DerStrom8

    DerStrom8 Super Moderator Most Helpful Member

    Joined:
    Aug 9, 2010
    Messages:
    5,484
    Likes:
    503
    Location:
    Vermont (GMT-5:00)
    Oh, so you wanted pin 9 to go high but not do anything? Seems a little odd, but ok.

    So what is the exact problem you're having? You aren't making much sense. Can you take a screen recording of the simulation running? Try a program like Camstudio if you don't have screen recording software already.
     
  19. D@rkL0rd

    D@rkL0rd Member

    Joined:
    Jun 22, 2014
    Messages:
    70
    Likes:
    0
    what i want is every pin of the deacade counter to go high on every loop for 1 sec ...i.e, any pin form 0-3 should for first 4 sec ...but in the first loop the first pin(pin 0)is not going high but in the next loop it is...
     

    Attached Files:

  20. DerStrom8

    DerStrom8 Super Moderator Most Helpful Member

    Joined:
    Aug 9, 2010
    Messages:
    5,484
    Likes:
    503
    Location:
    Vermont (GMT-5:00)
    Oh, I see what you're saying now.

    Could you post the schematic you're following so that I can get straight which LED is R1, G2, etc?
     
  21. DerStrom8

    DerStrom8 Super Moderator Most Helpful Member

    Joined:
    Aug 9, 2010
    Messages:
    5,484
    Likes:
    503
    Location:
    Vermont (GMT-5:00)
    By the way, I have simulated this myself and I, too, only see Q0 on for a fraction of a second before going to the next output. I'm not sure why this is happening, it may be a SPICE glitch....
     

Share This Page