Given a triggering event (PIR sensor), I'd like to trigger the following sequence:

• Move servo to one side

• Pause for 1/4 second

• Move servo to other side

• Pause for 1/4 second

• Repeat the above four steps

• Ignore input for 3-4 seconds

I know I can do this with something like an ATTiny, but was wondering if it could be done with a handful of 555s.

What do you think?

 

Sounds like a job for a cheap 8-pin microcontroller and a few lines of code.

 

This company makes modules that can do what you want.

http://www.pololu.com/