International, Inc.STI-V34150 Wireless Battery Powered Driveway Monitor with Voice Receiver

Update: I last wrote about this product in January 2018 (see article below) and wanted to pass along a few more observations noted since then.1) Sensor sensitivity setting: I've achieved the best results by using the "Medium" setting which is attained by removing the small black rectangular jumper, leaving all three control pins exposed. Plenty of sensitivity to detect vehicles while drastically reducing the false alarm rate due to electrical storms and strong wind. Remember, the slightest movement of the sensor will cause an alarm.2) Condensation: If water vapor condenses onto the circuit board then false alarms will occur until the condensation evaporates. I had one sensor prone to condensation in late morning to early afternoon in the summertime only. As discussed below, I placed a cloth inside the sensor to help absorb the condensation. However, I found a much better solution that involves sealing the circuit board with a clear urethane coating. As a test, I placed an unsealed sensor into my kitchen freezer for 24 hrs. to make the circuit board extremely cold. After pulling the sensor out of the freezer, a very fine layer of condensation formed. I installed fresh batteries and the sensor sent continuous false alarms until the condensation evaporated. This test was repeated several times with identical results. To create a waterproof barrier between the circuit board and the alarm-causing condensation, I sprayed the circuit board with four fine coats of clear urethane. I repeated the tests and Problem Solved - no more false alarms! The sealer product I used is CRC Seal Coat available on Amazon. Very simple to apply and specifically formulated for electronic circuitry and will not alter the functionality of the sensor.Hope this helps and don't hesitate to contact me if you have any questions.January 2018As an RF engineer I've been evaluating and testing this product for over a year and maintain a rather elaborate setup of six sensors and two receivers which feed my surveillance DVR and activate spotlights when a vehicle approaches. I'd like to share a few lessons learned and address the two most common issues reported by users.1) Sensor occasionally misses vehicles or detects them going in only one direction, either up or down the driveway: This observation can be caused by multipath fading where the signal from the sensor reaches the receiver by two or more paths. The vehicle appears as a big reflector and its size, shape, speed, and angle relative to the sensor can cause multipath and prevent the receiver from properly processing the transmitted signal. Fortunately, there are a few things you can do to minimize the effects of multipath fading and improve the performance of the driveway alarm system. The key is to maximize signal strength at the receiver by doing the following: a. Achieve line-of-sight: If you stand next to the receiver and can’t see the sensor then you don’t have line-of-sight. If at all possible, locate the receiver on a window sill with a direct path to the sensor. Otherwise, mount the receiver closest to the ceiling (higher the better) on an exterior wall. Interior and exterior walls attenuate the signal so avoid placing the receiver behind multiple interior walls. A brick exterior wall can reduce the signal reception range by half. b. Use an external antenna: Sometimes it’s not practical to mount the receiver near the ceiling so use an external antenna to accomplish the same goal. c. Use a repeater (STI-34109): If possible, mount the repeater in the attic or highest point in your home. Although this adds additional cost, the receiver can now be located practically anywhere in the house including the basement. I have a repeater and it works amazingly well and requires no additional programming. d. Sensor: Locate the sensor as close to the receiver as possible instead of at the end of the driveway. The sensor should always be located where the vehicle can’t pass between it and the receiver. Otherwise, the wireless signal from the sensor will be blocked by the vehicle and never reach the receiver. e. Local interference: While not a multipath issue, you’d be surprised to learn how many wireless devices throughout your home use the same frequency (433.9 MHz) as the driveway sensor. Devices on the same frequency can interfere with each other and give the false impression the driveway alarm system is not functioning properly. In my home I have a wireless subwoofer and outdoor thermometer causing interference so I just disabled them.2) Sensor worked great for the first few months then started alarming continuously: This could actually be a few things including a weak battery, low signal level or in my case condensation. I installed the sensors in January of last year when the air was cold and dry. However, once the warm and humid weather arrived in June, a few of my sensors started alarming continuously. Upon inspection I noticed water droplets had formed on the inside lid of the sensor and was dripping down onto the circuit board causing the endless number of false alarms. As a simple fix I covered the circuit board with a piece of super absorbent towel (Quickie Original Towel – Home Depot) and replaced the lid. The towel has no effect on the sensor and almost any absorbent material should work just fine.Bottom Line: The majority of reported issues about this product are caused by the unsuccessful reception of the sensor’s transmitted signal and not a faulty magnetometer. Unfortunately, the laws-of-physics and Mother Nature can cause a bit of frustration.I’m here to help so if STI technical support can’t resolve your issue then feel free to send me an email at [email protected] (yes, it’s a real address). I’m not affiliated with nor have a financial interest in STI. My help is absolutely free – retired engineer trying to stay busy.

I purchased this item since we live out in the middle of nowhere and we own about 20 acres. Our driveway is rather long and sometimes hard to hear when folks are coming up -- at night it's so dark you generally cannot see much w/out light. Since my husband travels a lot for work this has been an excellent safety feature for our home. I specifically purchased this since it detects metal and not motion -- We live in the woods and have all sort of critters running around.I have had this for a couple of months now, so far its worked really well! The instructions were a little hard to follow but set up was just fine. I have the receiver sitting in the window of our living room and the sensor a little bit down our driveway and it picks up every single time a car comes up our driveway. I like that there are a ton of alarm options pick from and the volume is loud (wakes me up -- but I sleep light)I have only had 2 instances when the alarm went off at about 11pm and there was no car -- It could very well be a neighbors dog running around w/ a collar or an animal that bumped into it? My husband only went out to investigate once and saw and animal running around down the hill (dark -- hard to see) the second time I just grabbed the gun and turned on lights since I was home alone :)

Ref Failures of two Safety Technology Driveway Alarms – See orders below.Gentlemen:I've purchased two of these units per the two orders below. Both have failed within a few months of use. I'll describe the sequence. The first unit was purchased on December 14th, 2017 and the second unit was purchased on July 1, 2018.Both units were installed according to directions within the package and worked perfectly out of the box. Around May we noticed a number of false alarms over about three days after which the unit stopped working. About a week later, I inspected the unit and after unscrewing the top of the transmitter, found an ant colony along with eggs between the circuit boards. Cleaning the unit's boards, did not help. The only egress possible would have been through 1 of the two millimeter holes in the bottom of the transmitter. I set this unit aside as a lost cause.Needing a long range driveway alarm and liking the Safety Technology unit, I purchased another unit, after putting ant poison around the installation area. This unit was installed around Mid July and worked normally until late September. In this case, there were no ants noted and no reason for the failure I could see after observation.After two failures, I am asking what to do. Obviously, I would like my money back as the units are not performing as expected or in fact at all?Please advise soonest as I need to purchase replacements.Sincerely,John Teer

Since my infrared driveway monitor goes off all the time from the wildlife passing in front of it, this "metal detector" one placed closer up the driveway works well as a reality check. Placement is key, follow the instructions, and you shouldn't have any large solid objects between the detector and the base alert chime for it to work well. Lightning strikes, even in the distance will occasionally trigger false alarms, just so you know. Got mine refurbished on Amazon for less than $40 and everything looked brand new! Awesome value!!

Ok, so it works most of the time. But for this kind of product, it needs to pretty much dingdong every time a car comes down the driveway. I'd say it is about 90% effective.The outdoor unit is around 1ft from the driveway edge and the indoor unit is just inside 1 exterior wall with a total distance of about 120'.