Start stop using one push button

[Lc85]

Hi,
I am trying to use the one push button to start and stop. I am using difu for the rising edge and a standard latch but my trouble is how to get it stop the second time the button is pressed. Has anyone any experience in this?

Thanks

 

[IRstuff]

This is generally a bad idea for industrial equipment, since there is no positive physical indication that the system has been turned on or off.

TTFN
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[Lc85]

This is just for exercise purposes. I am having trouble writing the logic to get it to stop.

Thanks

 

[IRstuff]

It should be just a toggle flip-flop.

TTFN
faq731-376

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[stevenal]

AND the state of the latch with your rising edge to determine wich direction to take the latch. SETLATCH=NOT LATCH AND REDGE. RESETLATCH=LATCH AND REDGE. Don't know what a difu is, but it sounds bad.

 

[dV8r]

"Don't know what a difu is, but it sounds bad."
I believe this is the instructors term for "plagiarism".

 

[CanadianTaff]

Forget what IRstuff says about bad practice, its actually quite common practice and nothing wrong with it, it has its uses.

The easiest 2 line code is as follows.

Pushbutton Trigger
---[P]-----------( )---

Trigger coil coil
--] [---]/[--+---( )---

Trigger coil |
--]/[---] [--+

The rising edge of the pushbutton turns on Trigger, then Trigger will make the circuit on branch one if coil is off, or break the circuit on branch 2 if coil is on, as its a one shot, the next scan coil will remain at the changed state.

Then coil can be used to energise a lamp or other indication so you know the status.

 

[vector721]

Hey guys,
I prefer to use a counter, but to each his own.