Car presence for garage door openening

I’ve been fiddling with this for a while. I’m a cheap SOB, seriously, cheap, so here’s what I’m doing, and what I would like some hopefully better suggestions for:

  1. Car sensor to tell me if car is in or out of garage.
  2. Based on time of day and car presence, my arrival sensor will trigger to open the garage when I get home.
  3. Only when house is disarmed (wife/kids are home) between 2pm and 11pm for when I come home from work.
  4. Life360 working as my presence sensor on my phone.
  5. RM obviously does this as I have multiple conditions.

This all works GREAT except point 1 is a manual virtual switch I trigger on when car is home and off when I leave in the morning.

Due to my cheapness, I have no additional zigbee or z-wave sensors, I do have an unused Insteon contact sensor. I built this amazingly Mad Max contraption from two pieces of steel hanger (like garage door openers use,) zip ties, some motherboard standoffs, a Cisco AP hung ceiling mount plate, and some blood.

When I drive onto the steel hangers, they collapse and the magnetic portion of the contact sensor moves down to the floor where the contact sensor is strapped to the apparatus. It’s springy enough (for now) and does trigger.

Then I have the REALLY bad Insteon Hub send my gmail a notification that it’s open or closed (except closed doesn’t work as it sends to the wrong email) and ifttt parses the gmail email to turn on/off the Smart Things virtual switch.

I tested this morning, moving the car out, sent the email, triggered the switch YAY!

Insteon makes ST looks like a reliable, stable, platform, so when I drove back on the “thingy” it closed the contact but email went to the wrong address. Stupid Insteon…

Anyway, that’s what I’ve got and what I want, anyone have some drastically simpler solutions short of buying a new contact sensor? And even then, some better way to make a wheel pad or something to trigger it? Optical sensor was a thought, but that would be too unreliable, need a physical “the wheel is on the pad so the car MUST be here” kinda thing.

I did try just having wire’s that would move to make or break contact with a spring type device but the Insteon contact sensors are crap and don’t work properly with more than a few INCHES of wire attached to their screw terminals.

Do you have a sensor on the garage door that you can tell if it’s open or closed? Is it a must for you to know if the car is inside or outside the garage?

I’d rather not have stuff on the floor - you could use the same Insteon sensor on a tennis ball on a string tied to a 6inch board on a small hinge mounted on ceiling. Mount the magnet on the board and the sensor on the ceiling at whatever distance it takes to make it reliable when your windshield pushes the ball 6-12 inches.

I’d also rather not use another hub so I’d use a ST contact sensor, but you maybe use Insteon for other things, sounds like you do.

Also sounds like your thing works as-is, n.b. you got ST you got lotsa complication anyway.

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Yep that’s a basic requirement.

Tried some variation on that, had thin wire from the contact sensor going down my string with a weight at the end (had that for years) and when bumped it would pressure the contacts together, but the Insteon would instantly go back to open even though it made solid contact. The garage is really tight so getting enough movement for the weight of the magnet would require far more space than I have to do it at the ceiling like you suggest, though that is a great idea, maybe with my wire contacts I can make that work… Thanks for that, might test it out tonight.

I did think about putting a presence sensor (old phone) in the car with life360 also on it, but then I’d have to worry about power draw over time killing the battery, and from what I’ve seen the ST presence sensors suck, or that would be an easy but pricey solution.

I haven’t had any problems with ST presence sensors. Maybe those people have the first generation.

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They are on sale too. But it can’t tell if your car is inside the garage or outside of the garage.

Yeah I was thinking about that as well, maybe wrap all but one side in tin foil so it only sees it facing a certain direction? Sideways for example, where in the driveway it wouldn’t be facing the hub, but in the garage it would.

How tight of a fit is it? Do you have to pull up to where the bumper of the car is almost touching the wall? If so, is there a place that you can put a semi strong magnet (hidden somewhere) on the front of your vehicle? If you can, put the contact sensor on the wall or object that you pull up to/tightly against.

That way when you move the car out, the contact stays open until you pull back in, close enough to that point where the magnet activates the contact sensor.

If you dont have the means to put the magnet on the car somewhere or dont pull close enough to the wall/an object, disregard this post and ignore me…

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No that’s a great idea, I have some totes that separate “my” space from my wife’s in front of the car, so limited means about 2" of free space, but the totes move a bit from time to time, I might be able to do something like that though…

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I realize you’re trying to not spend any money but how about this? Bed Exit Alarm System For Senior Fall Prevention - Low Cost Fall Prevention

Based on the description, there would be an audible alarm until pressure was reapplied, and no ST integration.

But you could try something like this:

Modifying a parking “chock” to have the contacts touch each other once the tire presses them together(since the linked one is only rated to 25lbs).

Yeah I forgot. You would also need to get window sensor. I’ve got a Bunch laying around and assumed everybody else does also. For some stupid reason.

you could make your own pressure Pad, they are cheap and easy to make yourself and wire the contacts from these up to a contact sensor so when your car is on the pad contact is made.

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You can build something with a Photon and ultrasonic range finder… i have one sitting on my garage door opener measuring the distance from it to the car. Depend on the distance, I can tell which car is parked under.

While your setup sounds interesting…

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Yeah yeah I know! The pad was something I thought of, if I do that I’d want a proper (non Insteon) sensor though.


I feel stupid. The crazy wild things I’ve tried to make one myself. I’m going to give this a try with short leads to the Insteon. Seems break and crush proof.

There is a better way to make it, i used to make them as a kid, if you use thick corrugated cardboard you just need to cut rectangular strips with 5cm width with 10 cm in between each strip in the Middle Layer and then coat the inside facing sides of the outer layers in tinfoil that all that is needed. corrugated Cardboard springs back pretty well and you will get good coverage and you can make a very large mat which can be covered with a carpet.