Rat traps!

I want to have a very simple system where i can know if rat traps get activated, for example: if i place 4 rat snap traps in my brothers house, 4 in my sister's house, and 4 in my house, i want to get a text/email that trap #2 in house #3 was sprung. I want the circuitry on the traps to be small and simple, when 2 contact pads conduct electricity, it will send a signal Bluetooth/RF/wifi etc to one master "Brain" unit that would contact me, the distance in an attic BT might be fine? Cost? battery life? And then should i have the brain unit connect to the wifi used by the homeowner to make contact with me? Or maybe a Sim card for it to text me directly?
Any thoughts or design help would be greatly appreciated.

In principle not too hard… just a matter of stringing the parts together. A simple arduino board eg a nano can do all the prcessing you need. Then a transmitter - wifi or GSM?

if you want to get the message on your phone, could that phone be miles away - ie out of wifi range?
in that case a GSM shield would be required.

Since the device will only be actvated rarely, battery life should be good.

regards

Allan.

Could just put ESP8266's on each trap, and have them report via wifi...

Have the trap actuator connect the battery to the ESP8266, and then have it squawk to your command control server via the site's wifi, and then have it go to sleep for a very long time (or just sleep forever - IIRC you had to connect two pins to make the sleep mode wake up again on the ESP8266). Be sure to remove the LED to minimize power use.

Super cheap solution, can be realized with a battery holder, a switch, and a $1 ESP-8266 board and the wires to hook them together

I'm going to an electronics warehouse an hour away from my house soon, it's like a huge candy house for all of us! I'm hoping to pick up some things to test this idea out, more for the shrinkify options like individual components, I'm hoping to get enough to test 4 rat traps: 2 rat traps at 2 different locations, could you help with a shopping list real quick?

To use esp8266, would they have to connect to the wifi the homeowner is using for Internet? Or can they simply connect to my main server aka arduino nano or whatever i have's wifi independently of the other wifi?

The esp is like a arduino with wifi built in no need of a nano. But to send data remotely it has to be on internet or closes enough to you. I use them with my phone to turn on lights but without using my wifi there range would be limited with wifi I can turn lights on anywhere.

What about my "master" board that the rat traps world report to, if i use the ESP8266 to squawk a signal to my "master" that would be monitoring, the master would need to also have wifi and then GSM to send an SMS text to me so what cheap options do I have? I am looking into taking a "Particle Electron" and adding a ESP8266 to it or maybe a board with wifi and adding GSM. Any advice?

The esp is a way more powerful uC but it's not as easy to use as the arduino because of I/O pins. You can send data over the web nothing else needed with it. I can turn on me lights from work from home from anywhere.
or read the temp feed the dog what ever I could dream up.

It's 32 bit core arduino is 8 bit that's like sending the data from your pc with a 4 core 2.2 gh to a old ibm 386

I don't think you understand my needs, just imagine that there is no wifi available and the rat traps are standalone devices, when one snaps i want to get a text message or email.

Guess you don’t understand that you can do that and more with a esp. And have a arduino based on the esp just not as easy to put together the parts.
I think banggood has some cheap 3g modules
Your rat traps going to cost a bit

Ok, take an ESP8266 and place it in the middle of a huge field with no wifi access, then turn it on, how would it text me?

A ESP8266 is like a Arduino with wifi.
A Particle Electron is like a Arduino with GSM.

so you can have network of ESP's for your trap's

and connect a Electron( or just a GSM shield) to one of the ESP's to get GSM

It's kind of redundant to have an Electron tied to an ESP(2 micro's) but those ESP's are cheaper than a wifi shield. But a GSM shield is probably cheaper than an Electron.

The same why you would a arduino with a gsm then you could talk to 10 or so more all over the field and let the mother trap text you what the ten said then at home with the wifi mother trap in the field can see how there doing to.
And send you text or email you one.

Hutkikz thanks for your reply, i think you understand my project, i think i like the idea of the cheap esp8266 and a 3v button battery and switch for my rat traps (do i need a special 3.3v button battery?)
I think this world be my cheapest (per rat-trap) cost.
Assuming there is no Internet connection where i place the trap, i am assuming to get these traps to notify me, i would need a "central command unit" the size of this does not matter but cost does matter. I know it will need to have wifi to communicate with the ESP8266's in the rat-traps and it will need cellular to contact me via e-mail, SMS etc...
So:
How far is the range of the wifi on the ESP8266 with a small button battery when connected to a central command unit with a stronger battery?
And what is my best options for cost savings on my central command unit?
I was thinking of adding wifi to a cellular board (such as a Particle Electron) using a cheap ESP8266, or adding cellular to a board with wifi already existing.
I hope this clarifies my needs for advice.
Thank you

Interesting project.
am I correct that the spring/wire of the trap closes a switch
that switch powers the ESP8266
getting power, it then outputs to anything listening "I'm alive, the Rat is dead"

GSM-1
the GSM is always powered, always listening.
once it knows an ESP8266 is alive, it knows which one sent the message and the GSM sends out the signal.

GSM-2
alternately. a master ESP8266 is sleeping/waking/listening
upon knowing another ESP8266 is alive, it turns on the GSM
the GSM comes alive, sends the signal.

dave-in-nj:
GSM-2
alternately. a master ESP8266 is sleeping/waking/listening
upon knowing another ESP8266 is alive, it turns on the GSM
the GSM comes alive, sends the signal.

This is how I would do it. you need one of the ESP’s to act as a wifi server anyway so why not just add cellular to that. I think it would be cheaper also.

The trap’s would only be powered when they are sprung and would transmit until the master acknowledges it has received the signal then shut down again. They could run for years on a coin cell.

The master could wake up regularly and check for signals and then go back to sleep or turn on the GSM and send a text then sleep. Because of the GSM and frequent turn on’s it will need a bigger battery.

Thanks everybody, could an esp working as a wifi server turn off another esp after it recieved a signal from it? What's the distance range? What's a going option for a cellular to add to the esp wifi server?

could an esp working as a wifi server turn off another esp after it recieved a signal from it?

No, but it can signal that it is ok for it to go to sleep.

What's the distance range?

I'm wondering this myself. My first lot of ESP's are on the slow boat from china at the moment. Typically wifi is in the 30-50 meter range. But I hear that the ESP has a pretty good transmitter and there are claims of 500 meters or more. IDK But as always much depends on how noisy the local environment is (i.e. downtown big city vs the Outback)

What's a going option for a cellular to add to the esp wifi server?

Pick your flavor.
Arduino GSM

RotorMotor2:
Thanks everybody, could an esp working as a wifi server turn off another esp after it recieved a signal from it? What's the distance range? What's a going option for a cellular to add to the esp wifi server?

deep sleep the ESP8266, since the Rat is no longer concerned with time and chances are, you are not really too concerned with the exact moment of it's demisem, you can wake every x minutes.

not sure what the power is for listening vs. transmitting but that would help cut down on your battery size.

use a solar re-charging cell back-up battery. no need for anything close to full sun as you will rarely use much power and all you need is a minute of power to send your txt. also no need to re-invent the wheel on that.

Not all esp can go long range there are ones that have ant jacks you have to pick them wisely
These have ant jacks and or told to have great range http://www.aliexpress.com/item-img/New-version-1PCS-ESP-07-ESP8266-WiFi-REMOTE-Serial-Transceiver-wireless-Module-ESP-07-UNO-ROBOT/32520995201.html?spm=2114.10010108.1000017.2.1C969h

And a link to where Id get the gsm https://www.aliexpress.com/af/gsm-module.html?ltype=wholesale&d=y&origin=n&isViewCP=y&catId=0&initiative_id=SB_20160905053810&SearchText=gsm+module&blanktest=7