I am getting a DSC alarm system that has a terminal which will go to ground upon an intrusion detection. The purpose of this terminal is to complete a circuit for any device of which you want to attach to it.
I would like to have my arduino email me upon intrusion through yahoo's SMTP server ( I know how to do this already and have it working) . What is the best way to detect if that terminal has gone to ground? I haven't been able to think of it electronically.
OR
Is there a better way to use my Arduino for a detection on my system than this terminal?