Electronic – Using a microcontroller to make a series of LEDs blink one after the other

ledmicrocontroller

This may seem like a nooby question, but I have a cycle light with 5 LEDs:

* * * * *

And it has a button, which when pressed hase different modes:

  • 1st press: all LEDs blink together
  • 2nd press: all LEDs stay lit
  • 3rd press: 1st LED goes on, then it goes of and 2nd LED goes on, so
    on till 5th, then 4th LED again…
  • 4th press: it turns off.

I was wondering how to make this. I can make a simple circuit so that all are on. I was thinking, that something like an 8-pin microcontroller can be used to make them blink together, but for them to blink independently, I guess I will have to use a microcontroller with enough pins so that each LED has it's own?

But my bike light is pretty small and I don't think it is running an AtMega32 or something. How does it work?

Best Answer

With 5 LEDs, 1 button, and 2 pins for power this is a perfect match for an 8-pin micro-controller. The hobby-friendly DIP-8 package would easily fit in your bike light, but the manufacturer probably used a cheaper un-packaged chip directly bonded to the PCB and put a blob of black goo on it. This manufacturing method is sometimes called "chip on board".