Showing posts with label Alarm. Show all posts
Showing posts with label Alarm. Show all posts

Monday, April 3, 2017

Coolest motion detection sensor


Intro

Ever want to build an alarm system?
The RCWL-0516 is a human body motion detection sensor. A sensor, that detects, through induction, human body movement. So it should only react if a body movement is detected. Moving objects should be ignored. How cool is that?

Wiring


Straight forward. 
GND => GND
5V => VIN
D2 => OUT

Pin 3V3 on the RCWL-0516 is an output. And the CDS-pin you can attach a light sensor. I will cover it in a later video.


Videos

Wiring & Use


ESP & detection tests





Code

Seriously? You set the pin, the RCWL-0516 is attached to, as an input. And if you register a 'HIGH' signal, you do stuff. Watch the video. Coding is done in 2 minutes.

Q&A

Update 29-05-2017
This sensor seems to get quite an attention. There are some questions that some of my viewers asks. Here is what I found out.

Q: Can you use the RCWL-0516 with an ESP8266? Or will you get randomly false positive results?
A: I've done a short term test with the ESP8266 on a NodeMCU board. It seems to work just fine. 
The ESP greater Version 12-E is shielded and is FCC certified. So it should, by definition, not interfere with other electronics.
 However one viewer reported randomly false positive results on a long shot.

Q: Is the water in the human body responsible for the detection?
A: Probably. I tested it with an empty and with a water filled bottle. And even with a cat. And it seems that the bigger the object the further away it can be detected.

Q: Can it be mounted mobile to detect persons? 
A: No. The sensor seems to be quite sensible to movement itself. Any movement of the sensor itself seems to trigger the output.

Q: Does the radiation of the sensor harm you in long term?
A: No. The Sensor uses about 30 milliwatts (mW). The radiation output is limited to that value. That is far less than your smartphone emits.

Links

Amazon

RWCL-0516
NodeMcu
Arduino Uno