7 seg led countdown

Discussion in 'The Projects Forum' started by masterchief, Aug 19, 2006.

  1. masterchief

    Thread Starter New Member

    Aug 19, 2006
    3
    0
    hi, I am building a countdown unit for my paintball marker.It holds 99 balls
    in the clip . i would like to use the 4511 cmos and 2 7 seg led common cathode. I need to know what chip would be needed for the countdown input
    this is what I it to do
    1. on power up w/ clip removed shows 00.
    2. when clip is installed goes to 99
    3 . when trigger pulled count goes down, marker can cycle as fast as 30 cyc pe sec.
    4. for night games the display needs to be blanked out, the 4511 chip has that capability.
    now for the fun part

    I know you could build a unit w/ a pic controler with all the bells and wisles
    and a lot less parts, i dont know the ist thing about about programming
    if any knows who could write the program i would like it to do this

    1. pwr up
    2. clip removed shows00
    3. cilp install shows 99
    4. counts down 1 for ever input
    5. when count gets to 10 flashes led
    6. when clip removed led shows 00
    7. have a provision for dimming
    8. have a night mode, led stays off until you press a switch


    if any one would like to help me w/ this programing



    thanks alot mc
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    Hi,

    You can do the counting with a couple of 40160 decimal counters. The other functions can be done in CMOS as well. CMOS will run into the 10's of megahertz, so 30 Hz is no problem.

    How are you sensing the paint balls as they are fired? That might be the hard part.
     
  3. masterchief

    Thread Starter New Member

    Aug 19, 2006
    3
    0
    I am going to use the sol output of the marker, running through a reed relay
    or a a solid state relay. what ever is easer.
    probily will need some type of debounce w/ the reed relay,
     
  4. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    HI,

    Can you tell me what a "sol" marker output is? Is that the solenoid?
     
  5. masterchief

    Thread Starter New Member

    Aug 19, 2006
    3
    0
    yes it is the solenoid , sorry my typing is not the best.it is a driven by a 9v
    supply.Thanks
     
  6. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    Hi,

    I don't have the details on the solenoid circuit, but the circuit attached should do the trick. I set Vcc for 12 volts, but the logig will work with anything between 5 volts and 18.

    Got the counter wrong in my first reply - now it's a 4510 up/down counter.
     
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