Please be patient, I understand this is probably an extremely simple question to someone who know what they're doing. My background is in automotive electronics and software development. What I'm attempting here is completely new to me (but very fun). I am trying to use a Raspberry Pi to check the 'open door' switch, and operate the wall switch for each of my 2 garage doors. This is part of a home automation project I'm working on.
I am using an old 18v laptop power supply, a buck converter to pull that down to 12v (For the 2 LED under cabinet lights I'm also running with the Pi), and an LM7805 regulator for the Raspberry Pi power source. The laptop power supply is plugged in to the same circuit as the garage door openers. I understand that my Raspberry Pi is isolated from the garage door opener circuits, and because of this I have no idea how measure voltage at the 'door open' switch or operate a transistor to short the wall switch to ground so I can operate the door.
The voltage at the 'door open' switch is 8 VDC open, 0 VDC closed to case ground. I want to use a transistor to operate the wall switch (20 mA max measured current to ground when operated) controlled by the Pi. The garage door openers (2) each have a 24 volt AC - DC converter for the logic circuits. I had thought about using this as a power supply, but was afraid is might not be up to the task since I'm also running 2 LED strips with the same device I want to use to operate the garage doors.
I hope this gives someone enough information without running on with too much. Thanks in advance for your help.
I am using an old 18v laptop power supply, a buck converter to pull that down to 12v (For the 2 LED under cabinet lights I'm also running with the Pi), and an LM7805 regulator for the Raspberry Pi power source. The laptop power supply is plugged in to the same circuit as the garage door openers. I understand that my Raspberry Pi is isolated from the garage door opener circuits, and because of this I have no idea how measure voltage at the 'door open' switch or operate a transistor to short the wall switch to ground so I can operate the door.
The voltage at the 'door open' switch is 8 VDC open, 0 VDC closed to case ground. I want to use a transistor to operate the wall switch (20 mA max measured current to ground when operated) controlled by the Pi. The garage door openers (2) each have a 24 volt AC - DC converter for the logic circuits. I had thought about using this as a power supply, but was afraid is might not be up to the task since I'm also running 2 LED strips with the same device I want to use to operate the garage doors.
I hope this gives someone enough information without running on with too much. Thanks in advance for your help.