New Arduino user here. Be gentle
Here's the story:
I work from home. My office is in my finished basement. My daughter gets off the bus and comes down to my office (before I'm done with work) every day. Some days I have conference calls that run late. My ultimate goal is to create an LED indicator on the upstairs door that lets her know whether or not I'm on the phone.
My thoughts:
My phone knows whether the line is in use --even if it's on a totally different phone in the house. This leads me to believe there's a (hopefully a relatively simple) way to determine whether or not the line is in use.
Here's what I need:
How do I design a circuit to detect whether or not my phone line is in use? I've searched the forums here and I've yet to find any tips.
Thanks!