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Sense when garage door is open. Light/LED light turns on? Answered

Hi there, I have an automatic garage. But sometimes i forget to close it and it stays open all night. Apart from someone being able to steal stuff, it would also allow an intruder into the house while we are asleep! So what I am looking to do is whenever the door is open, that a light inside the house turns on. My garage door is a panel lift door. My initial thought was to use alarm sensors. One on the wall and one on the door. If the sensors are not near each other, a light in the house should turn on. The serial circuit would look something like the following. GarageDoor > GarageDoorSensor > Less than an inch of air/space > WallFixedSensor > Wire > CentralLogicDeviceWithBattery > Wire > TinyLight/Led. The hardest bit would be what I have called the CentralLogicDeviceWithBattery. I would like to know what parts i would need and which part connects to which part. thank you


An alternative is to train yourself not to leave it open. Assuming you get out of the car and go into the house through a door - put a "thing" on the door handle that says "shut the garage!". Maybe you just wrap it with cord and have something like a key-ring dangling from it - when your hand hits it you'll get the reminder? L

A simple micro switch on the door and a suitable lamp in the house would do the trick for a fraction of the cost of a microprocessor system.

Kilt Y

9 years ago

It sounds like you have the logic part down pat and are well on your way!

If you wanted to get fancy and go all out you could check out: https://www.instructables.com/id/Garage-Monitor-3k/

...a more budget minded schematic is attached.

1)Garagedoor-> Sensor
-Use a reed switch with a magnet in such a way that a circuit is closed whenever the garage door is open. (You could also use contact switches, pressure switches, IR etc.
-Modify a night-light attached to a wall to give your circuit power only when it's dark (Instead of turning on a LED night light, it outputs a logic "high" for the garage switch to operate

2) Sensor->Wire
-You could use a small RC toy's Radio Transmitter and reciever to make the project wireless. Just add an NPN transistor or some kind of amplifier to make sure the radio switch operates

-Attach the receiver/wire to another amplifier circuit. Use a transistor styled amplifier or an OPAMP circuit to boost the receiver's juice
-Attache the output of this Amplifier to your LED/relay for your home lights.


Hi YakAttack, Thank you so much for taking the time to help me. The first link looks awesome, also because i can use it to know how far i need to drive the car in. Thanks also for the other information you provided. I will visit my local radio shack and we'll see which way i go. Ill start this project next weekend. It could take some time, especially with the initial investigation; and hope to give you a "I have succeeded" message one day. Have a great day! Cheers, Mike