Hello. I am tasked with solving a pretty difficult problem so I was hoping that you could help me. So I have some traps that I have set up about 20 mi apart within a 50mi radius. When the trap closes, I want to be able to send a signal to from the trap to a receiver. This way I know that the trap has closed and I can go release what was caught. This would save much time and gas from driving and checking each trap every day.
I have found a couple of things, but are extremely expensive. Essentially, I need something that can send the most basic signal data such as a number indicating which trap. That is it.
I have looked into using an App called Securet RemoteControl which will allow me to take a picture from any cell phone and have it emailed to me. In other words, I would put a cell phone in a box out by the trap with the App running. I would send a text to that phone from mine and it would send me a picture letting me know if the door on the trap was down. The problem is all wireless companies make you pay for a data package per phone if the phone is Android. But 10-20 phones and the data plan is way too expensive.
I have thought about having a connection on the trap door, that when closed sends a signal to a homemade phone attached to the trap (or having a short circuit until the door closes and completes the circuit) to send the last text containing a unique ID to my phone. Made from something like this, I was guessing: https://www.sparkfun.com/products/9427
I am guessing I would have to buy antenae and sim cards for each trap as well.
I have tried to think of radio signals for the cost effectiveness, but the range isn’t that great.
Any information or ideas you can give would be great. I am trying to keep it cheap and no monthly fee if at all possible, but not a breaker. I just can’t do a data plan for every phone / trap. If you need more information, don’t hesitate to ask. I appreciate the time! =)
Wow, I guess I did leave out some information haha. Perhaps it’s because I am a complete noob to this. I’m a computer science person, not so much on the hardware
Essentially, these traps would be set around the mountainous region of AZ. I know that while hunting and such, we get cell coverage for the most part with Verizon. It is hilly, dry (for the most part), temps can range from 90* to -10*. I would also need to worry about protecting it from the elements, but I wanted to make sure the task was doable before worrying about other things.
Personally, I was trying to keep it cheap as possible around $200/trap max. Unless I would need a cell plan as well then I am not sure. I know the data plans are just too expensive. I was hoping to get supplies cheap enough if I were to buy in bulk or something.
Yes, 10-20 traps should be more than enough.
There have been problems with vandalism in the past (although illegal and had to charge a few people). I will pretty much have to cut my losses unless a small lock can be made between the comm device and the trap. However, they can just as easily steal the trap. I have used a camera in rural areas. I set it to view the trap and if someone messes with it, I can identify who it is and serve them with papers about how it is illegal to tamper with traps. In short, I am not sure this will be a problem at the moment.
As far as establishing relay points, it may or may not be possible. I know that traps are spread out between highways and stuff and I can’t just put them in the middle of the road. I would really have to plan the traps then. Depending on the range and how often I would need a relay point, is what it really comes down to. But yes, I can do that if that as a use case if I find a solution.
I would like the system to be able to sustain itself for 2-3 days at a minimum. There was talk of lithium batteries, or shorting the circuit until the door closed to not use battery life until it was needed. Charge packs are something else I have heard of.
Battery type doesn’t matter. As long as they are rechargeable, I say that is the only requirement.
So I can ask questions, but I do not have a good answer for you. Often getting into a room with a bunch of people and asking questions tends to bring forth a solution.
It would appear that a single mesh network with one cell phone access point is out. The mountains and the inability to place relay nodes at will would be an issue. But perhaps a few mesh networks (like XBee or ZigBee) with their own cell phone access points might be the solution.
Short of a custom RF solution, using satellite radios, or stringing cables across the country side the cell phone system appears to be you best bet. GSM modules are available that would allow you to post a simple text message. No need to even identify the trap as that would be done by the unique telephone number the text would come from. If this is your approach, you would need the GSM module, a small micro, a battery, a power regulation module, and an interface to the trap.
With something like a reed relay on the trap door, the animal would turn on the device when it enters. The micro would boot up, and configure the GSM module and then send a text. It might then do this every few hours just to make sure the fist message was not lost. It would then do this till you reset the trap or the batteries died. Nice this about the reed relay or other physical switch is that zero power is consumed till the trap is sprung. You could go months on very small batteries.
I have not used GSM modules, but I understand they have an “AT” interface like models of the 1980’s. Should not be to hard to program. I am also at a loss for off the head costs. I would assume the enclosure, micro, battery, and power module might be as little as $50-60. Have no clue on the cell phone module, the sim card, or the fees for the cell phone.
Another solution would be to use multiple mesh networks. That that you would need to carefully layout the traps and relays to get a viable network. The issue here would also be that the system would be consuming power all the time. Sounds like the module approach would be best, but perhaps more expensive.
Cellular is the perfect solution for this appliation - I’ve designed dozens of different remote sensors using both GSM and CDMA. Your best bet is to send an SMS message rather than send “data”. If you get your service through an MVNO that specializies in M2M your rates can be very low.
Thank you fll-freak. It appears this may be the best way to approach the problem.
"Short of a custom RF solution, using satellite radios, or stringing cables across the country side the cell phone system appears to be you best bet. GSM modules are available that would allow you to post a simple text message. No need to even identify the trap as that would be done by the unique telephone number the text would come from. If this is your approach, you would need the GSM module, a small micro, a battery, a power regulation module, and an interface to the trap.
With something like a reed relay on the trap door, the animal would turn on the device when it enters. The micro would boot up, and configure the GSM module and then send a text. It might then do this every few hours just to make sure the fist message was not lost. It would then do this till you reset the trap or the batteries died. Nice this about the reed relay or other physical switch is that zero power is consumed till the trap is sprung. You could go months on very small batteries."
Gsm Man, do you happen to have anymore information as to the actual ‘how-to’ of creating what I am describing. Sorry, I just am not sure what all is needed and how to go about it. I have seen various antenae and interfaces to various SIM cards and such but not sure what is required (what I need v. don’t need). You say that you have done something like this in the past with M2M. How would I go about getting a plan for M2M and establish / setup the link between device and phones (self made phones?). I apologize for asking to be ‘hand-fed’, this is just new territory to me. I appreciate the help nonetheless/ =)
