Arduino Cam Timer

I have been doing Arduino work for some time now, but I have a specific need and I was hoping to get some advice. I am building a prop computer. It will have about 180 incandescent lamps. The lamps are divided into 8 circuits that flash in a sequence. I have already used a 16 channel relay board to make them flash in sequence, but I need them to overlap, in other words, one circuit will stay on after another circuit has just come on. In the original prop, a 3 RPM motor turned cams that switched the circuits on and off.
How do I make some of the relays "overlap" the others? I have read about Millis and I believe that would work. I am slowly figuring out millis by looking at some of the online tutorials but I still don't quite get it.
Again, I am just looking for direction as to where to learn
Thanks
Murphy

JMT2825:
I have been doing Arduino work for some time now, but I have a specific need and I was hoping to get some advice. I am building a prop computer. It will have about 180 incandescent lamps. The lamps are divided into 8 circuits that flash in a sequence. I have already used a 16 channel relay board to make them flash in sequence, but I need them to overlap, in other words, one circuit will stay on after another circuit has just come on. In the original prop, a 3 RPM motor turned cams that switched the circuits on and off.
How do I make some of the relays "overlap" the others? I have read about Millis and I believe that would work. I am slowly figuring out millis by looking at some of the online tutorials but I still don't quite get it.
Again, I am just looking for direction as to where to learn
Thanks
Murphy

If this is all your Arduino program will ever do, then millis is not needed. Change the code so you turn off a relay AFTER a you turn on the next relay, and after a short delay.

Paul

There was a similar topic addressed here a few months ago. I wasn’t terriblely impressed with the outcome as I thought the whole thing could have been table driven but it’s worth a read.

Approach to control 9 model fog cannons

Ultimately, it is my belief that it would be fairly easy to replace a cam timer with a table driven Arduino program. It comes down to how many microswitches, how many lobes on the cams and how fast does it rotate...