4017 36 LED chaser?

[Gryd3]

Can I ask you one more thing? Because I can only have 8 outputs and 8 doesn't go into 36, if I were to add 5 4017s to get 40 outputs which would cover the 36, would I be able to make it skip past the last 4 outputs as I preferably want 36.

I haven't dug into the spec sheet too much again yet, but the method you are currently using to daisy chain them together... can you not substitute in one of the output pins to reset display?

 

[Louis Bates]

here's my circuit, right now I haven't added the extra 4017's. But the 0 pin of the far right 4017 is constantly on and I want to skip that unless there is another way?, for some reason it won't turn off at the right time???

 

[Supercap2F]

Can I ask you one more thing? Because I can only have 8 outputs and 8 doesn't go into 36, if I were to add 5 4017s to get 40 outputs which would cover the 36, would I be able to make it skip past the last 4 outputs as I preferably want 36.

Yes you can make it so it counts through only 36 outputs and then resets. In the data sheet the last stages Q9 output is connected to the reset on the first stage. Just move the reset pin from the Q9 output to the Q4 output on the last stage. They have it set up in the data sheet so that on the first stage it will count through Q0-Q8 but on all the other stages it will only count through Q1-Q8.
Is that what you where after?
Dan

 

[Louis Bates]

Yes Thank you so much for helping I couldn't have done it without you

 

[Supercap2F]

No problem, Louis. If you have any more questions don't hesitate to ask!
Dan

 

[Louis Bates]

Another question

I need to somehow make a length of time that my LED chaser is on for, as it's roulette then it has to be random.

Supercap suggested that when the button is held down a capacitor fills up, then discharges when it's let go, if this is fast enough then would that work

Thanks

 

[Supercap2F]

OK, here's the circuit I suggest:

It's not original to me, it's out of the book "CMOS Cook Book by Don Lancaster". The way it said to work is: When you press S1 it slowly charges C1, increasing the VCO output frequency. When you let off of S1, it discharges C1 through R1, decreasing the VCO output frequency. The VCO by itself would just keep outputting slower and slower pluses. But the when the pluses slow to a certain length, the monostable (first 4013) starts up and holds the second 4013s output low, cutting off the rest of the VCO output pluses.

I don't know just how good it works.... So maybe someone can confirm its feasibility.
Dan