Knight Riderlight for truck

A CD4017 combines the count and decode functions into one chip. As mentioned above, add two quad XOR packages as gated inverters controlled by the ff.

Knight Riderscanner light with sound

Note also that the original KITT used incandescent bulbs which have a perceptable rise time and a notably slow fall time, possibly enhanced electronically (e.g. it might be an electromechanical action with capacitors added). Thus, KITT had a "trailing edge" behind the sweep. If you want to do this with LEDs, you'll need either a lot more logic, or something analog to simulate the attack-sustain-release behavior seen here. Watch this on desktop not mobile - then you can use the , and . keys on the main keyboard to single-frame through the sequence.

Knight RiderLED scanner Light

As mentioned above, change to an up/down counter whose direction is controlled by the ff, driving the 138 decoder. This feels like the minimum-chip-count solution using discrete logic.

Stack Exchange network consists of 183 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Now you know why everyone gets this wrong. They either double-beat at the ends, or they totally forget about attack/sustain/release and blink the lights on and off abruptly.

Note that it did not dwell for a double-beat on the 1 and 8. So you actually have a sequence of 14 steps. Thus we arrange them like this.

Knight Rider lightsfor car

Knight Riderlight Bar original

You could use a counter with up/down capability like a 4029 and have the first and last decoded outputs toggle a flip-flop on the UP/DOWN pin. Or a microcontroller, which would allow you to have any pattern you want and e.g. cycle through them with a switch.

Knight RiderLED light scanner Bar Red

I was thinking of using a flip-flop (76N) for the multiplexer selection, but I have to get a clock signal when either all bits are 0s or 1s.

So nothing easier. Set up logic for a 14-light marquee, then merge 02 and 14 to drive lamp 2, 03 and 13 to drive lamp 3, etc.

Electronics noob here. I made a simple follow-LED circuit in one direction using a 555 timer, a 93N counter, and a 138N decoder. Now I want to make it go back and forth.

I could use an AND gate for when all are 1 and a NAND for 0, but how then I would have to select from those two on some kind of condition. But they are not clock signals.

With inverters and multiplexers, I think you are heading down a relatively complex path. Search for knight rider schematic to see how others have solved this.