Want my garage door to open when the car is started remotely - How to do this?

Hardware
1

We got a new car for the wife, and it has remote start. If she were to use it while the car is parked in the garage and it’s closed, how could I trigger the garage door to open? She leaves for work every day at 5:30 am, so I guess I could time it in the mornings, but I’d rather it be dynamic for other times.

I was thinking I could use a carbon monoxide detector mounted real low and it would trigger when it detected carbon monoxide, but at that point theres already a build-up, and I’m sure the wife would rather not take the baby out in that.

I’m considering doing something like this, to detect sound. A starter is a very jarring sound when everything else is quiet, that would probably work very well, although I’d be nervous if it did not trigger the automation. So I was thinking I could use one of my many hue bulbs to color indicate it was opened, or one of the google homes to announce that it was opened. And then maybe even use the carbon monoxide detector to open the garage in the event all the others fail.

Does anyone hae any other thoughts about achieving this?

2

Not a fully baked solution but here are the ingredients:

The accessory outlets on many vehicles are only powered-on when the car is operational. That means if you were to install a beacon powered by an accessory outlet, it would only be functional when the car is running. Therefore if the beacon is active, the car’s engine is running. Combine that tidbit of information with a closed garage door and you have all the information you need to act on it (send a warning message to your wife’s phone, open the garage door, flash all the lights in the house, whatever).

The challenge is to find a suitable beacon. There are Bluetooth beacons but they tend to be battery-operated (given that they are designed to be used as always-on tracking devices). Perhaps there’s a way of modifying one so that it’s powered exclusively by an accessory outlet.

This idea is not foolproof. Here’s a false-positive: the car may be on the driveway with its engine running and the garage-door is closed.

Alternately, you use a battery-powered Bluetooth beacon in her car and detect its signal-strength when the car is parked in the garage (as opposed to its signal-strength when parked on the driveway). You can use that as means of detecting its presence within the garage.

A completely different approach would be to use an ultrasonic sensor mounted within the garage to detect the car’s presence. Combine that with the beacon and now you know when the engine is running and the car is in the garage (as opposed to outside on the driveway).

BTW, the CO detector is an interesting approach but you’ll need to find one that can transmit a warning signal that you can receive and use to act on.

EDIT

Need to know:

  • Is the car in the garage?
  • Is the car’s engine running?
  • Is the garage door closed?

If the answer is yes to all three then it’s a potential hazard and we act on it. The challenge is to detect the first two conditions.

3

Sounds like it could be a potentially dangerous automation to rely on, proceed with caution:

  • False positives could result in a dangerous CO build up but could be mitigated by a CO sensor as a failsafe as you said.
  • False negatives could result in your garage door opening in the middle of the night or when no one is home.

In addition to what was said before me, you could use a RPi Zero in the USB port which is only powered on when the car is on and use the monitor (or presence) script, here: [monitor] Reliable, Multi-User, Distributed Bluetooth Occupancy/Presence Detection

4

I agree. It should be considered to be a second line of defense with the first being good operating practices … like never starting a car remotely from home unless you first see it parked in the driveway.

FWIW, I’d put a CO detector in the garage, period. If you enter the garage and the detector is screeching, open the garage door, get back in the house, wait for it to clear (and remotely turn off the car).

1 Like
5

Does the car have builtin Bluetooth for hands free phone calls/audio? That only comes alive when the car is on. Could you put a pi zero w in the garage and have it update HA when it sees the car’s Bluetooth signal? This is a suggestion and a question as it has me thinking about some garage presence ideas.

6

I use two OpenGarage sensors to detect whether our cars are in the garage.

7

Maybe you can start car from obd2?

Below is python library for obd2.
Just monitor car condition and send request from car upon start+connected to WiFi +door close
https://python-obd.readthedocs.io/en/latest/

If possible to start with obd2 it’s possible to have RasOi in car that acts as sensor an connect to your main HA. From within main HA you car request car start and door open based on conditions.

EDIT
Year/make/model/trim level of car would be relevant

8

Agree with posts above regarding caution… this could lead to disaster, however:

  1. I LOVE my opengarage (and opensprinkler) some of my most robust kit
  2. in terms of sensors, think:
  • Motion
  • Vibraion
  • Sound

  1. Have a look at the service that is behid the remote start and see if there are any webhooks or other command line type sensors you could trigger an automation with…

  2. You could look at ODBII device that will detect ignition start and then you use something like traccar to do the trigger in to home assistant via state…

Loads of options, however proceed with caution… then pick whichever one suits your wallet/coding/environment contraints… :slight_smile:

9

here the doc did this

works well I have working in my place

and this

10

Do the headlights come on when the car is started? Could use a light sensor to trigger the door.

11

These are all great suggestions. I want to have as many checks as I can with this automation, if I even decide to do it.

The wife’s vehicle is never parked in the driveway, so that really wont be an issue. I like your idea of a BLE Beacon, and I seen some further recommendations on that line of thought below.

12

It can definitely be dangerous, and I haven’t decided to even do it yet, but I did want to see what the options were. I plan to have as many checks in place as possible if I decide to go through with it.

The RPi Zero is an interesting idea. The thing has 8 12v sockets in it, so finding a place for it will not be an issue.

You’re right about the false positive, but I run my security system through Node-RED so I’d know if it was opened…as well as everyone else in my house, lol.

13

I actually plan to do this either way now, after thinking about it. If there’s a co2 build up, open the garage and turn on my shop fan.

14

It does, but I do not know if it broadcasts outside of adding a phone to it.

15

How do these work exactly? The site doesn’t give much info.

16

When you say start with OBD2, what do you mean? The remote start is something I installed, it’s a Fortin Evo-All remote start.

17

The remote start is by Fortin, it’s the EVO-ALL kit.

I looked into a OBDII device for traccar, but all the info I found was extremely out of date. I’ll need to do more research.

18

I’ll check these out, thank you!

19

I use them purely as distance sensors.
In our garage they are mounted on the beams above each bay and report distance back to HomeAssistant.
For us, 225cm = an empty bay, and around 75cm = car in bay.

They can be used in a variety of ways including as garage door openers. The instructions are also available if you want to go the cheaper route and build one yourself.

21

That is actually a really good idea. What Home Assistant integration did you use for these?