Reliable Driveway Alarm

This solution is not mine, I have borrowed with pride and figured I would share for the benefit of the group.

Might Mule (FM231) makes a highly reliable driveway alarm that senses the presences of a vehicle based on a electromagnetic sensor that buried next to your driveway by detecting masses of metal moving within a 3-12 ft. This eliminates false alarms based on animals, wind, sun, and etc. This unit has a wireless range of 400 feet which is great if you have a long driveway. The unfortunate part is the alarm receiver does not have signal outputs to connect directly to dry contact sensor (Aeotec Dry Contact Sensor Gen5; ZW097-A). To solve this I soldered leads to the visitor LED contacts and added a RED LED (Radio Shack LED 5mm; 2760330/NTE3144) to the leads outside of the receiver enclosure. Now when a vehicle breaks the electromagnetic field the visitor LED flashes and the new RED LED also flashes. Then I picked up a photocell sensor from Home depot (Hampton Bay Photocell Sensor Wire @ Home Depot; ZB2-262468-1500 SKU# 1001543162). Using a drinking straw with a white interior and cut to about 1 inch lenght I placed the added RED LED into the straw and placed the photocell sensor at the other end. Secured the RED LED and the photocell sensor to the straw. Now when the mighty mule visitor GREEN LED flashes the RED LED will flash as well, which is registered by the photocell and the signal is sent to the Aeotec Dry contact sensor. It took several LEDs to determine the correct LED for the entire setup. The green LED wave length is not compatible with the photocell sensor and white LEDs require more voltage than is available from the existing visitor LED leads.

Parts List
1.) Driveway Alarm, Might Mule FM231 ~ $65
2.) Red LED, Radio Shack LED 5mm; 2760330/NTE3144 ~ $3
3.) Photocell Sensor, Hampton Bay Photocell Sensor Wire @ Home Depot; ZB2-262468-1500 SKU# 1001543162 ~ $15
4.) Dry Contact Sensor, Aeotec Dry Contact Sensor Gen5; ZW097-A ~$35
5.) Drinking Straw


Very interesting approach, My driveway is 35’ wide though and it appears the specs say it only handles a 12’ radius. I might have to dig around to see if there are any that go wider. I have been considering photocell solutions as well. After thinking about this more, I suppose my underground dog fence might set this off as well?

Depending on your driveway surface (crushed stone, 21AA) just bury it in the middle. Then you cover a width of 24’, which leaves 5.5’ per side and most vehicles are wider than 5.5’ and the driver would never hug the edge of the driveway. Usually people use the middle of a driveway.

Concrete :confused:

Just purchase two sensors and place one on each side of the driveway, then set the sensors frequency equal to the receiver.

That would leave 11’ un-monitored in the middle which I think is a little too much to be unmonitored, still mulling it over though. I may get 1 and put it by the end of the driveway since i’m on a near a dead end and there’s only 3 houses past me.

Hey, thanks for the instructions on how to do this.

I went to HD and bought the mighty mule driveway alarm but when a visitor comes and the base unit alarms, the green visitor light comes on and stays on until you push the reset button. The visitor light is not flashing. Do you think I have a bad unit?

I am interested in the answer to this too, as I had read somewhere else that the LED stays on until pushing a reset button. If that is the case, I don’t think the above design will be practical, because the signal will just stay on after the car goes by. I’m hoping Spyder1 may have some additional insight on this. Maybe it’s possible to connect the RED LED to the chime, instead of the green LED? I don’t have this Mule unit yet, but understand the chime just goes off once (which is what I think we’d want for this solution).

I returned the might mule alert and bought the Dakota driveway alert and everything is working great now. The Dakota has alot more range and it has a set of triggers on the base unit I was able to connect and Aeon dry contact sensor which activates when the drive alert notifies of a visitor. I use the driveway alert to start recording on security cameras and flashes a light inside and it has been working very well.

OK, this is great to hear… thank you. Just to be sure, is this the unit you’re using?

Also, you just connected the output relay contacts of this unit directly to the Aeotec, and then incorporated the Aeotec into your ST… and are triggering off of that? Sounds like a great solution!

No, I’m using the until that has the sensor you bury underground next to
the driveway. We have too much wildlife for the motion sensor.

Here is a link.

If using the Mighty mule you need to connect the leads to the Visitor LED that flashes RED, not the green LED that confirms the unit is on. Then with SMART things you can set up a rule that only responds to the first flash of the Red LED.

On the mighty mule I bought at home depot the visitor led would come on when activated and would stay list until someone would press the reset button on base unit. That’s why I returned it for the Dakota.

Yes, I have the Aeon sensor connected directly to the Dakota relay on the base unit and named the Aeon sensor Driveway alert. When it’s activated I have it programed to turn on my arlo Cameras and record, notify my phone and chime inside. It’s been working really really good.

I took the valuable conversation from this thread and installed a Dakota MURS driveway sensor and relay. I could use some guidance from the team on getting my driveway sensor setup to meet my objectives.

-Dakota Alert MURS Wireless Vehicle Sensor, Black (MAPS BS Kit)
-Aeotec by Aeon Labs ZW097 Dry Contact Sensor, Small, White
-ST v2
-4x Amazon Echo devices

Relay driveway activity from Dakota M538-BS to Aeotek ZW097
ST to SMS my mobile phone upon driveway event
Get my 4 Amazon Echo’s to announce someone is in the driveway

Dakota installed 1000’ down driveway and all is working great
ZW097 wired to the relay on the back of the M538-BS
ST device handler setup (to reverse open / close) on ZW097
ST can see the ZW097 device and logging events
ST SMS to phone working


  1. What is the proper ST configuration to send an SMS to a mobile phone when ST recieves a state change from the ZW097? (I found 4 different ways to do it in ST - and not sure which is the proper one)
  2. Is there a way to have ST send an event to the Echo’s to announce someone is in the driveway?

Appreciate your time helping me learn ST. Thanks

I did some research and ended up putting a ‘driveway’ alarm in. I found something similar to the Dakota mentioned above that was cheaper (Safeguard). It includes relay output to control a zwave device for comms to Smartthings if desired as the Dakota does. I am not currently using this but wanted capability for future in case I found the need.
This uses PIR sensor that can be up to 1000 ft from base and it is working well. Because it senses anything in front of it, I have had a few ‘false’ alarms due to birds, however, I have had NO false alarms due to sun, trees blowing, etc.
You can plug in base station or use 3 C batteries to mount it anywhere you want. There is LED and sound that includes something like 16 different sounds. It can be set to LED flash, sound, or both. There is no ‘off’ switch so you would switch to LED flash only if you did not want sound.

I have the mighty mule mentioned earlier.

Instead of using the led, I wonder if you could hack it using the tone generator output instead to trigger a dry contact.

I have the same requirement with the possible exception of having the ZW097 activate a Smart Lighting Local automation, which requires a device that is also LOCAL. Can you tell me if the ZW097 shows ‘Local’ under your Device List Execution Location?

My internet connection is slow and unreliable so I am trying to avoid ST cloud processing.

Can’t get this to work. Did you set any jumpers special? Dakota 2500 & Aeotec sensor. Wired to channel 1 Com & Open on receiver. Any thoughts would be appreciated.

I just did a writeup on how to do this using a Dakota Alert alarm with the built in dry contacts. Not trying to hijack the thread, but since the OP is posting a driveway alarm solution from someone else to help the group, I figured he wouldn’t mind this as well:

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