/diy/ - Do It Yourself

>>1287519
>Currently learning some discrete logic
I don't see how this can be done with your 374 D-FF construct (maybe it can) but if you use a standard shift register like the 74HC164 there should be a way to change the direction by chaining a second register and wiring the lamps (e.g. LEDs) _between_ the outputs of the first and the second register. Like Q0A - Q7B, Q1A - Q6B .. Q7A - Q0B. First all outputs of register B are L and one after another lamp comes up until Q7A goes H. Now register B begins to fill and one after another lamp goes off (starting with Q7A - Q0B because both are now H) until all outputs (A and B) are H and all lamps are off. Then you clear both registers and the next cycle begins. I'm hoping this is complicated enough..

The obviously much simpler solution is either the universal shift register (74HC299) mentioned earlier or: 4 bit up/down counter (74HC4516) -> 4-to-16 decoder (74HC4514/15) + some control circuitry = up to 16 lamps, back and forth.

Also, consider cleaning up your mixed bag of logic families. All your functions are available as 74HCxx, e.g. 74HC374/574 (574 only has a different pinout).