I'm interested in creating a sequencer for a full-sized traffic light. I'm totally new to this kind of project and I'm curious about the best way to get started. While I know I could just buy one online, I think making it myself would be pretty cool! The lights will be using LEDs, but they'll be powered with 120v. Any tips or ideas?
4 Answers
If you want your traffic light to make some clicky sounds, grab a 4-channel relay module. For a silent setup, use an SSR (Solid State Relay) module instead. Both can connect to an Arduino board, letting you customize it however you like. You could even add some sensors like proximity or sound for extra fun!
You really just need an Arduino Uno or Nano clone paired with a 3 or 4-channel relay board. Connect each light to a separate relay, and then spend a quick 10 minutes learning how to use the DigitalWrite function to control your relays.
Dive into the world of Single Board Computers! An Arduino Nano clone or a Raspberry Pi would work great, especially if you're into Linux. Most boards have a demo program that blinks an LED. Once you get comfortable with that, you can learn how to control relays or SSRs with it, using different pins for more functionality!
Back in the day, I built a traffic light with relay logic, which was fun! Nowadays, I'd suggest going for something simpler like a 555 timer circuit or an Arduino. Just search for "traffic light controller circuit diagram"; there are plenty of creative ideas out there.

Just a heads up, some SSRs might let a bit of current through when they're supposed to be off, which could cause the LEDs to flicker. You might need to add a 'ghost' load to fix that.