Product : Electron with Control Everything Relays.
Concept : Monitor the status of each door of a car (usually a light is provided by default at the main car console as well, i can use that to pick the contact). If door opens, notify the user. Furthermore user could prevent the car to start. Possible options here to disconnect battery terminals ? New to this kind of project. Any help / suggestion would greatly help me.
I haven’t looked into OBD-II IC yet. Tapping into OBD can that be a more practical option ?
Monitoring the interior light using a voltage divider (to drop voltage to < 3.3 vdc) to protect the analog input pin would give you the door entry part.
You would not want to disconnect the battery (to large a relay / current). You could interrupt the starter solenoid (would not stop the engine if running.
Interrupting the ignition (assuming gasoline engine) could shut the engine off, but a failure or shutdown at the wrong time could be dangerous in traffic.
Preventing the start would likely be best and then tracking the location if it is already running.