I am working with a 74HC193 binary up/down counter, and am trying to set up a button to increment or decrement it. The procedure to increment a single step as I understand it is:
- Set pin 4 high
- Wait for change to propagate (30ns or more)
- Set Pin 5 high
- Wait again
- Set both pins low again.
Since it is a button, I am not worried about speed in any way. I would be perfectly happy to have a 2ms pulse followed by a 1ms pulse 1ms later. In my research online, the most promising way to make a pulse is a monostable 555 circuit. I was thinking two of those wth different T values might work, but I can't tell from that page if I can put it on a delay. That seems like a fairly decent debouncing mechanism as well, but I would like a little more control, like a 2ms pulse but 500ms before another input is accepted. Is that possible?
If it is too hard to get two pulses with the proper timing, I suppose I could just hold the count down line high and pulse the count up line once, but that removes my ability to have an additional button to count down.