I recently received this 2-wire door detection sensor (see image below). How can I connect it to my raspberry without causing it damage? The problem is that it was given to me by a friend who unfortunately does not remember the name of this sensor (he kept it in his closet for a long time). All I know is that it is a door sensor with electromagnet and 2 wires. After a ride on google, it seemed to me that the principle of using all sensors of this kind with raspberry is the same. But I have seen fritzing where the two wires are connected directly to the GND and to another gpio of the raspberry. Yet some articles talk about using a resistance ranging between 1-10khm to protect raspberry. This is the reason why I post this question, I would like to have some help on how to proceed. I use a raspberry pi3 ]1