Reliable Z-wave/Zigbee motion sensor for house porch

Hello folks,

I have a home integration which would use my Harmony smart hub remote control to turn on the TV and switch the HDMI input to display my security cameras outside when ever someone walks up to my front door of my house. This integration works exactly as I expect but I periodically get false positive for motions.

The current motion sensor that I have is Smartthings motion sensor. This piece of crap sensor kept on providing false positive and at times would just remain positive until I remove the battery and re-insert to reset. I thought that I it is defective so I bought another one from Amazon and new sensor also occasionally have false positive for motion.

Perhaps these Samsung Smartthings motion sensors are not designed to operate outdoor even though it is under a covered porch? I tried the Ecolink sensor, but it seems to be a bit slow to send signal to ST when detecting motion. So can anyone recommend a motion sensor for me that would work outside of the house but under a covered porch that would provide lease amount of false positive?

Much thanks in advance.

All PIR motion sensors have problems outdoors. It doesn’t matter whether they are zigbee or Z wave or what the brand is.

This is because the sensors are actually heat detection sensors and they measure a very small amount of change in heat moving across the field.

When you put them outdoors, Just a breeze moving across them or a random shaft of sunlight can set them off. So none of them are designed for outdoor use.

You basically have three options.

One) rely instead on the motion sensors that come built into cameras, these usually use a different kind of technology and are much more accurate outdoors. So for a front porch many people just install a video doorbell and use the motion detection from that.

Two) use multiple motion sensors in a zone and only trigger your alert if they all detect Something at the same time.

Three) put a piece of PVC tubing over the detection lens on the sensor to significantly narrow the detection field, but also protect it from breezes. This works well for some use cases.

All of these are discussed in detail in the outdoor motion sensor FAQ, so I suggest you look at that next. (This is a clickable link)


Motion sensors are kind of complicated devices, you need to be aware of how they work to optimally place/position them.

Two good ones with great battery life are Monoprice and Ecolink.

If you want control over the “size” of the object that triggers motion, I would consider the Ecolink sensor. If you want control over “distance” from sensor to trigger motion I would consider the Monoprice sensor.

They are designed slightly differently and the jumper pins on the device behave differently as described above.

I had no luck with plain motion sensor outdoor. The sun and cloud shade cause too much false positive. I started noticing this behaviour since I rarely get issue during winter time and night time. There is whole theory about this in google.

Long story short, I found bosch motion sensor like this. Their “TriTrech” come with 2 independent sensors (microwave & PIR). They will confirm each other before it will trigger. Since using this sensor, I never get false positive. Just a warning though (I may not get a good batch), mine is hard to adjust. It will require you to adjust the sensor during installation to match the microwave and PIR on the area you want it to cover. This is not easy to get it right at least in my experience.


Thank you for your response, I am VERY interested. So my issue is probably the same as yours and many others in regards to PIR motion sensors being outdoor, but being covered such as house covered porch but facing false positives. Lately I’ve done countless online searches for solution and I did come across the Bosch motion sensor that mentioned about their “TriTech” features.

Looks like the one you mentioned is “Bosch ISW-ZDL1-WP11G” and it’s $41 from Amazon. I am gonna order it now and give it a try since I’ve spent way too much time over this issue. How is the response time on this sensor? I need a motion sensor with fast response time for my particular integration.

I have four IP security cameras outside of my house so when anyone walks up to my front door, the motion sensor will tell ST to trigger a routine scene which would then tell Alexa to issue command to my Logitech Harmony smart remote controller to turn on the TV and change HDMI input to the security camera input. This works beautifully so when we’re watching TV at home and a package delivery or anyone approaches the porch then our TV will switch input and show us who’s outside.

I will order this sensor and give it a try and will report back to this thread and let others know how it turns out.

Thanks again for your response!

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I believe that is the correct model. I got the DTH from a member here tomasaxerot.

It worked as is. I do not have to make changes.

In term of latency, the first signal of motion after idle state will depend on smartthings latency. It is depend how much of the code will end up local in the hub and remote at cloud. The DTH most likely not in local execution. I am not sure what smartapp you will be using, it could be run on cloud as well. Please take that into consideration. It could take some time before your camera can react to it. This latency may not be constant due to cloud in play. I am also guessing that since you already have the same setup, you will be fine.

For subsequent motion immediately after that one, please look at the manual for the bosch to get the exact number. I do not remember the exact delay time. Bosch delay the next detection for a few minutes. This behavior is common with some other motion detector. This is to save energy/battery on busy traffic area.

Hi Roberts,

Much thanks for your response, it was very helpful and with your information I did more searching around and eventually found my solution. You are correct about PIR sensor not being reliable outdoor due to climate variation factors. I searched around and found other folks discussion about similar problem and the “Bosch Tritech Motion sensor”.

Other people said that this particular sensor is exactly what they needed to solve this problem because it uses both PIR and microwave combined to eliminate false positives. I had it installed for nearly a week now and so far no false positives!