Adam_Smith
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Joined: Tue Jun 19, 2018 12:29 pm

Secret Mission Motion Sensor

Tue Jun 19, 2018 12:31 pm

Hello guys :)

I need help in finding the best approach towards a stealth project. I am operating a mission in my home where I need to ensure that I cannot get flanked / approached by someone from behind and not notice. Basically I will need to construct a couple of motion detectors that:

1) Are reliable and won't trigger randomly.
2) Are very small and easy to deploy.
3) Aren't expensive, so if they get destroyed or lost it wouldn't be the end of the world.
4) Work in the dark.
5) Are able to send a message / notification to a device REMOTELY. I can't use anything that makes a noise like buzzers etc.

I've thought of trying to interface an RF system where as soon as the motion sensor detects motion, it uses a connected RF transmitter and sends a signal. But how would I interpret the RF message, and on what device?

A second idea that came to me which I think is more realistic is to set up a raspberry pi server, hosting a simple webpage on my home network. I could then use an esp8266 Wi-Fi board together with a small arduino and motion sensor to send a packet of data to the webserver whenever the motion detector is triggered. I would be connected to my home network from my mobile and be viewing the page, so I will get informed whenever there is motion detected.

What are your thoughts about the potential solutions I have described? Are there any alternative methods that I should consider?

Thank you,

Adam.

Idahowalker
Posts: 239
Joined: Wed Jan 03, 2018 5:43 pm

Re: Secret Mission Motion Sensor

Tue Jun 19, 2018 9:02 pm

These cheap things work real well

RCWL-0516 Microwave Radar Sensor

at detecting motion.
Being a programmer: She says go to the store get 1 bottle of milk, if they have eggs bring back 6. She gets mad cause I brought back 6 bottles of milk.

mattmiller
Posts: 1864
Joined: Thu Feb 05, 2015 11:25 pm

Re: Secret Mission Motion Sensor

Tue Jun 19, 2018 10:34 pm

In my house, I use a PIR connected to a PiZeroW running Node-RED and configure it to send an alert to my phone (I use Pushover free service myself for this)

PS The RCWLs mentioned above are fine as well but they pickup movement behind walls so I just use PIR to just monitor one room

PhatFil
Posts: 235
Joined: Thu Apr 13, 2017 3:55 pm

Re: Secret Mission Motion Sensor

Wed Jun 20, 2018 12:32 am

check out the (£8) sonoff rf bridge https://www.itead.cc/wiki/Sonoff_RF_Bridge_433 when reflashed with alternative firmware on its onboard soc (esp8266) such as Tasmota https://github.com/arendst/Sonoff-Tasmota/wiki your no longer tied or reliant to the chinese servers.

With tasmmota on your bridge and a Pi providing a Mqtt broker and some control s/w such as node red its all (well mostly..) web page configuration and drag n drop control ;)

however in practice using some of the cheapest 433mhz pir devices aliexpress could provide on occasion if 2 devices A and B are triggered in fairly quick succession first A then B the mqtt signal from B can arrive ahead of that from A..

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Gavinmc42
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Re: Secret Mission Motion Sensor

Wed Jun 20, 2018 1:31 am

The problem with radar is you have to sit still.
How about two of these on a hat.
https://www.sparkfun.com/products/14768

With a head up display, it would be like eyes in the back of your head
https://www.sparkfun.com/products/11315
I'm dancing on Rainbows.
Raspberries are not Apples or Oranges

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OutoftheBOTS
Posts: 609
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Re: Secret Mission Motion Sensor

Wed Jun 20, 2018 3:58 am

PIR sensors are cheap and see at night well because they see body heat so also are not set off by other motion not involving heat(windy blowing doors/trees).

The cheap Easy way to link these things remotely is with a ESP8266 node mcu via MQTT message to your RPi

Adam_Smith
Posts: 4
Joined: Tue Jun 19, 2018 12:29 pm

Re: Secret Mission Motion Sensor

Wed Jun 20, 2018 6:45 am

OutoftheBOTS wrote:
Wed Jun 20, 2018 3:58 am
PIR sensors are cheap and see at night well because they see body heat so also are not set off by other motion not involving heat(windy blowing doors/trees).

The cheap Easy way to link these things remotely is with a ESP8266 node mcu via MQTT message to your RPi
I'm quite a novice when it comes to setting up an MQTT broker and subscriber etc. Are there any specific tutorials you recommend? Also, ultimately I must receive the motion alert on my android phone. How can I achieve this?

Adam.

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bensimmo
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Location: East Yorkshire

Re: Secret Mission Motion Sensor

Wed Jun 20, 2018 7:22 am

Are you walking around the room and if so will you be wearing the device on yourself ?
(that's the way I read your question ?)

A more powerhungry way is to use a PiZeroW and a IR camera and some higher 900nm+ LED's (these shoudln't glow to the eye)
just put a small screen in front of your eye in a helmet cam.

Adam_Smith
Posts: 4
Joined: Tue Jun 19, 2018 12:29 pm

Re: Secret Mission Motion Sensor

Wed Jun 20, 2018 7:59 am

bensimmo wrote:
Wed Jun 20, 2018 7:22 am
Are you walking around the room and if so will you be wearing the device on yourself ?
(that's the way I read your question ?)

A more powerhungry way is to use a PiZeroW and a IR camera and some higher 900nm+ LED's (these shoudln't glow to the eye)
just put a small screen in front of your eye in a helmet cam.
Sorry, I did not word my query well. I need to place motion detectors in a staircase and in a room close to my position, not on myself. In fact it is essential that I don't trigger it myself and cause a false positive detection. So if someone is coming up the stairs silently I need to know so I can get away quickly, and if someone is entering a room that leads to my position I will be notified on my mobile and can escape / hide while I have the chance.

p.s. this may sound like some sinister plan but it is a prank on my sibling and nothing illegal, I just want to plan it out well hehe

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Gavinmc42
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Re: Secret Mission Motion Sensor

Wed Jun 20, 2018 8:32 am

Wireless Alarm system, PIR with dialer.

PIR sensor on a Zero W
https://www.adafruit.com/product/189
Some smtp code to email you a message to your phone, add Pi camera to send you a pic.
But this depends on email timing.

Perhaps Pikrellcam with motion detected triggered script.
Does MotionEye OS send message on movement?

The Zero case will fit the Pi Camera, just need the software and USB battery bank.
Can you conceal it so that it overlooks the stairs?
I'm dancing on Rainbows.
Raspberries are not Apples or Oranges

Adam_Smith
Posts: 4
Joined: Tue Jun 19, 2018 12:29 pm

Re: Secret Mission Motion Sensor

Wed Jun 20, 2018 9:26 am

Gavinmc42 wrote:
Wed Jun 20, 2018 8:32 am
Wireless Alarm system, PIR with dialer.

PIR sensor on a Zero W
https://www.adafruit.com/product/189
Some smtp code to email you a message to your phone, add Pi camera to send you a pic.
But this depends on email timing.

Perhaps Pikrellcam with motion detected triggered script.
Does MotionEye OS send message on movement?

The Zero case will fit the Pi Camera, just need the software and USB battery bank.
Can you conceal it so that it overlooks the stairs?
I have the exact same PIR sensor as the one you linked! It's quite a decent one. I will consider smtp, however it is definitely not the quickest and most reliable. Pikrellcam and MotionEye are cool but since there is a risk that I'll end up losing the devices I can't afford to be using Raspberry Pi Cameras and stuff. Just a motion detector that sends a notification via mqtt / wifi is what I need. There isn't much room to hide it so the system must be as tiny as possible.

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Gavinmc42
Posts: 2050
Joined: Wed Aug 28, 2013 3:31 am

Re: Secret Mission Motion Sensor

Wed Jun 20, 2018 10:56 am

This spy camera can be mounted away from the Pi.
https://www.adafruit.com/product/1937
I have even seen camera/microphones hidden in power points

Stairs got carpet?
Vibration/pressure sensor + tiny RF transmitter.
MAX1472 is a SOT23-8 package, very small.

A Piezo buzzer element makes a good shock/vibration sensor.
Got access to underneath the stairs?

Laser tripwire?
Those microwave/radar detectors can work through walls depending of the wall type.
Ultrawide band ones are good for that.
Or up from under wooden stairs?
Hollow banister railings?
I'm dancing on Rainbows.
Raspberries are not Apples or Oranges

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