Open/Close Door sensor based on acceleration

[JDRoberts]

There are several different use case categories for door sensors used in security systems.

The first just tells you that the door was moved. That would be typical on a safe or a liquor cabinet. I already gave you the link to the Honeywell security system accelerometer sensor that’s used for that purpose. You disarm the system before you open the door. You close the door again before you rearm it. So it doesn’t need to know “open” from “closed” – – it just knows “moved.”

The second tells you that a door is open. This is typical for A door that opens and closes a lot where you either want to know that it was left open when it wasn’t supposed to be or you want an event to trigger from the door being opened. This is actually more common for home automation than for home security, and you had said you were interested in security. These devices generally require both an accelerometer and a gyroscope. Notion and Korner fall into this group. But the truth is it’s cheaper to use a reed sensor for these use cases, so that’s what most security systems use for this purpose. The read sensor will also have a longer battery life.

A third looks at garage doors, where a tilt sensor can be used because the door is opening against gravity.

You have to decide which use case you’re going to address. You can’t address all three in the context you’ve given, because they don’t have the same kinds of power draws.

If your number one priority is power draw, why use an accelerometer at all? A reed sensor will beat you on battery life every time.

Korner’s value proposition isn’t battery life. It’s ease of installation because it’s only one piece instead of two. It has sufficient battery life, but again it’s not going to beat a reed sensor.

Korner has filed a patent. One patent. And it is based on the use of a novel combination of components that allows a functional one-piece door and window sensor, as opposed to the the two-piece sensors that have been used for decades in the industry. It is innovative, and useful. It is much easier to install and use, and in many respects it works better.

So I’m just confused about the context driving the selection process. Why specify accelerometer in the first place?

[Moonknight]

Thanks for the respond, you made it easier for me to explain
The company already has reed solution - and that is the sensor I’m looking to replace - they are looking for a one-piece device.

90% of the doors and windows I’m aiming at are not tilting - so the tilt sensor is not the solution for me.

so basicly the proposition I’m looking for is a reliable open/closed door sensor, not based on reed with long battery life.

[JDRoberts]

False alarms have always been higher in the past with accelerometers than with reed sensors. Improving that is supposed to be what’s covered by the Korner patent and why many people are watching it closely. Expectations are that they combined a proximity sensor with an accelerometer, but we don’t know yet. But those are serious hardware engineers (look at the resumes of the founders) doing serious design work. Not something you’re going to compete with with an MCU and an off-the-shelf accelerometer.

https://www.kornersafe.com/ourteam-defaultcontroller.ez

In any case, long story short, if you’re limited to prebuilt pieces it sounds like you need an accelerometer and a gyroscope and your battery life with 433 is going to be two years. Not longer. with zwave plus it will likely be less.

To do any better you need hardware design people, and there’s still no guarantees unless you have a patent level breakthrough.

JMO, of course.

[Moonknight]

Proximity? I couldn’t locate one on the PCB (attached are pics I just took) and how does it go through the plastic shield?
who do you think it works? with the door/window frame? what if the door/window doesn’t have a frame?

BTW, If I’m looking to join the ones who follows the patent is there any site, community you recommend?