Pi Traffic Lights

[RowlandoGloom]

I think I'd like to see opto isolators used in anything that interfaces mains to logic in a school environment (says someone who has been known to directly drive mains Triac chopper circuits from an Arduino at home!).

 

Just a quick update. The relay board I purchased (as with most) come with a 817c optocoupler per channel built on to the board as a means of safety.

Here is the relay I used