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Magnetic Door Switch

Former Member

Hello,

 

I have a existing alarm system which has a magnetic door switch connected to it.  Would it be ok to connect the same switch to the PI?  i.e. connect a pair of wires  from the PI to the same input as the switch on the alarm panel?

  • Is ir possible to connect more than one magnetic switch? If yes, whatbisbthe pinout to thw raspberry's gpios?

  • in reply to atux_null

    This is a 3 year old thread, it may be better to start a new one with the new questions !

     

    in the meantime, there is nothing special about the fact the switch is magnetic, the magnet is just the actuator, the switch part is just like any other, two bits of metal that get pushed together or pulled apart. (With the exception of hall effect switches of course). If a switch contact is already connected to another device, you should be really careful about connecting it to the pi directly, the voltages etc could be very wrong and result in a damaged PI. Use an opto isolator or something in this case.

     

    If the door switch is a typical one, there is a magnet embedded into the door itself and a small "Reed" switch in the frame (This position may be reversed on occasion but the principal is the same)

    There is nothing stopping you adding a second reed switch right next to the first, they would then both get activated by the same magnet, one goes to the alarm, one to the PI

    For the PI, google for the numerous articles on adding switches to the PI, again I would be tempted to use isolated ones as even long lengths of wire can pick up surges and damage the PI if not correctly protected. A suggestion for the control software on the PI would be Node-Red, this is awesome for home automation and sports a graphical workflow editor and fully supports the GPIO of the raspberry pi