Lighting LED's randomly

Discussion in 'The Projects Forum' started by Hyfromatriac, Aug 9, 2014.

  1. Hyfromatriac

    Thread Starter New Member

    Aug 9, 2014
    6
    1
    Hi, for a school Tech Studies project, I am making a dog toy which essentially works on response to stimulus to reward the dog. It works in the following way:

    There are 4 buttons on a hollow circular body with a detachable Lid. The buttons light up randomly, one at a time, and when the button which is lit is pressed, some food is lifted to the surface of the toy.

    Currently I believe I can do this with a 555 timer, but I'm not entirely sure how. Can anybody direct me in the right direction for this light randomization? Also, if you have any ideas on how to raise the food (currently I plan on using a solenoid) to the surface, or launching it, that would be great. Many Thanks

    - Attached is the general design of the lid and buttons, specifications of the body and just a 3D model of the button itself -
     
  2. ericgibbs

    Senior Member

    Jan 29, 2010
    2,499
    380
    hi,
    A 555 will not give a sequenced output, it could be used to step a 4017, which would drive the LED's.
    Do you want this 'dogmatic' :rolleyes: to be running continuously?

    Also how do you plan to power the project.
    E
     
  3. Hyfromatriac

    Thread Starter New Member

    Aug 9, 2014
    6
    1
    thanks for the reply. Yes, as long as it is switched on, I'd like it to be running. However, the project is not set in stone, so if it would be harder to have it running continuously, I can change the design to accommodate this. And I will be using common batteries, probably just 9V. Again, I can change this to a power socket if needs be
     
  4. Alec_t

    AAC Fanatic!

    Sep 17, 2013
    5,766
    1,101
    Have you considered the timing of events? What is the interval between one LED switching on and the next LED switching on? How long should each be on for?
    Are you able to use a microprocessor to control events?
     
  5. wayneh

    Expert

    Sep 9, 2010
    12,087
    3,027
    Those little indoor putting practice things use a small solenoid to kick the golf ball back after a successful putt. That would probably be about the right amount of kick to fling out some kibble. But I don't know how you handle the reload, and how you sequester the food away from a probing tongue.

    I'd consider a screw auger that turns for a set time. This would gently convey the kibble from a reservoir into an opening from which the dog could remove the treat. I don't know where you'd get the auger parts, but the motor could be as easy as the stepper motor from an old printer.

    A similar approach could be that used by a candy machine - a chamber that rotates and is filled by gravity from a reservoir and then delivers an aliquot to the "customer" when it rotates 180°.
     
  6. Bernard

    AAC Fanatic!

    Aug 7, 2008
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    395
    Darn- new scanner only covers about 10 in, will add last 555 tomorrow, if desired.
    Random lightning of LEDs by old fast clock- slow clock driving 4022 [ or 4017 different pin out ] 4 bit counter. Lit LED on for about 1 sec., increase 470k to increase time. If LED #3 is lit, U4-A output will go low if its SW is closed, missing 555 will be triggered, powering solenoid, releasing latch- lid flies open- treat expelled. Cycle can stop or continue in 5 sec.
     
  7. Hyfromatriac

    Thread Starter New Member

    Aug 9, 2014
    6
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    Thank you so much Bernard, that is extremely helpful, hopefully all goes well!
     
  8. MrSmoofy

    Member

    Jul 28, 2014
    112
    5
    This made me think of [​IMG] for dogs :)
     
    Metalmann and ErnieM like this.
  9. Bernard

    AAC Fanatic!

    Aug 7, 2008
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    Picked remainder of IC's. We thought that you were gone, had some other thoughts like a SW lock-out, so if a paw was resting on a SW & he got lucky & that ckt was selected , he got the treat.
    LED's should have a seperate driver, if 4022 [ or 4017 with pin # changed ] as loading output too far will drop output V below a logic hi. needed as input to NAND.
     
    Last edited: Aug 14, 2014
  10. Hyfromatriac

    Thread Starter New Member

    Aug 9, 2014
    6
    1
    Okay, I will keep all this in mind. I am just in the process of picking up all these components, I will be sure to post progress here if you would like to see. Thank you very much again
     
    Bernard likes this.
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