This is a review for the Mighty Mule FM231 Wireless Driveway Alarm. Some driveway alarms that you install will detect everything that comes down your driveway (including dogs and people). This one is geared toward detecting cars only. The Mighty Mule FM231 is a newer version than the 131 (I also have a review of the 131 listed on my site as well).
Let’s start with the basics of how a driveway alarm works and the basics of how most alarm systems work. You have a sensor and then something trips the sensor. That something can be a person, a car, an animal. It just all depends on how the driveway alarm is setup. For this particular driveway alarm, it has to be large metal body. This works on the principle of radio frequency induction. This is the same principle that lets your car trip the red light at an intersection. So if you are looking for a driveway alarm that is only going to work for cars, then consider this model. After being tripped, the sensor will send a message to the receiver. You will place the receiver somewhere inside your home where you can hear it when it goes off. So you then have some advanced warning that someone is coming down your driveway.
So how do you choose if this driveway alarm is right for you? Well, the first question is the most important. What do you want to know about what is in your driveway. Do you want to know anytime someone walks down your driveway or just drives down it? If you want to know when someone is walking down your driveway, then consider another model, but this one is great for cars because of the way it is designed.
You can put the receiver, or base station as they call it, up to 400 feet away from the sensor. That’s pretty far and further than most people have driveway. The chimes are not overly loud or annoying and this doesn’t go off when someone is just walking in your driveway. I saw this recently on Amazon for $79 dollars but there was a better deal going on at Home Depot for around $56 dollars.