By Sam Holland, co-founder of informal

Why this crossed our desks: After seeing the complicated design of the SimpliSafe Water Sensor, and the simplicity of the Temperature Sensor, we wanted to see how the Motion Sensor stacked up. This sensor is the most baffling of the ones we’ve torn down so far, and has the least in common with the other SimpliSafe accessories. It stands out from the Water Sensor and the Temperature Sensor, due to the internal architecture and electronics used. Our assumption is that an external contractor or manufacturing partner did the design work on this sensor — or that it was maybe the first product made by the team.

The button and battery wiring could’ve been eliminated with a simple redesign, creating cost savings from not having to hand-solder items together, and reducing complicated assembly steps. We found the fastener-free assembly to be very difficult to disassemble, but well designed.

We wonder if the first version of the design had more screws to hold everything together, and they shifted to using snaps later in the product development process. There are some circular molded plastic features that don’t need to be on the housing, which sometimes means they’re artifacts from modifying the tooling later. Anyway, this was a fascinating teardown for all of these reasons. Read on to understand how we arrived at this conclusion!

Table of Contents


Overview

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The Motion Sensor uses a technology call passive infrared (PIR) to detect motion within specific areas and then alerts the SimpliSafe hub.

The shape of the sensor and position of the adhesive strips allows the user to either mount the device flat on a wall, or in a corner. Neat!

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Battery cover removed

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Opening it up

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Opening up the Motion Sensor was tricky!

I wonder if the design initially had screws holding the housings together, which were later eliminated by closing up the holes on the rear housing.

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Inside the Motion Sensor

motion sensor inside.PNG

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Cool feature: Fresnel lens

motion sensor cool feature 1.PNG

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*This article from MuRata explains the use of lenses in depth and is a great read.*

Pro Tip: SimpliSafe recommends placing this sensor 6 feet off the ground to detect the largest amount of motion. If you have pets, they recommend flipping the sensor upside down and mounting it 4.5 feet off the ground to ignore anything crawling around on the ground.

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