DIY Arduino & Raspberry Pi Security System

jeegro

Adventurer
Pi doesn't seem to play nice with RCA/composite signals... so I'll have to dig deeper there.

Another question is a cheap, easy, and effective way to charge the small battery* that powers this system. I guess I could hook it up to my dual batt system, but I'd prefer if it ran on its own battery.

I want the truck to charge the battery if the voltage is greater than 13V (i.e. solar or alternator is running) but I want it to be 1 way only.

A diode?

* something like this: https://www.amazon.com/Alarm-Back-Battery-4-0ah-5-0ah/dp/B002RLQXBU/ref=sr_1_4?ie=UTF8&qid=1494883495&sr=8-4&keywords=security+backup+battery
or https://www.amazon.com/TalentCell-Rechargeable-12000mAh-Multi-led-indicator/dp/B00ME3ZH7C/ref=sr_1_2?ie=UTF8&qid=1494883819&sr=8-2&keywords=12v+lithium+battery

I should probably just hook it up directly to my dual batt...
 
Last edited:

Semi-Hex

Enfant Terrible
Like the concept. Just started looking at a similar system last week at the OE show. I have also been looking at the parts to get something setup. However, I am not a computer person and have no background in this field (outside of working at Atari in the 70's). It needs a longer range with a gateway perhaps (up to 6-7 km), a two way speaker if in case the person showing on your screen is your friend or not and you could tell them hello or gtfo. I've been looking at part on https://www.tindie.com/browse/iot-home/
 

Kiriesh

Adventurer
I've not heard of long-term issues with embedded arduino solutions but YMMV. One thing to keep in mind, RPI's don't like hard shutdowns. You'll probably want a capacitor and voltage monitor setup to trigger a shutdown if you run low on power. You may also want to lock the microSD to read-only and run a separate storage device for actual read/write stuff, SD cards like to corrupt after a while if you're writing constantly so it'd be unreliable as a security system. Just my $0.02.
 

jeegro

Adventurer
After doing some more research, the tech doesn't seem to be there for handling multiple high res cameras - let alone multiplexing - on the Pi. The Pi also wants digital/USB cameras where I was hoping to use analog as the 12v options (blind spot, backup cam, etc) are much more abundant.

I will focus first on the arduino/alarm/sensor side of the project as that seems pretty straightforward.
 

JPaul

Observer
There are several open source software projects for video cameras that have all kinds of bells and whistles such as facial recognition, movement detection, etc. Motion is the one I'm leaning towards (that's it's name, "Motion"), another is ZoneMinder. There are some others as well as ones that require a paid subscription to unlock everything. I'm not sure how much a Pi could handle running those, it all depends on how you set it up. You'd probably be better off running it on a slightly more powerful compact PC running Linux.

The IP camera's aren't a terrible idea, but you have to really lock those things down, most of the ones that you can get actually have firmware in them that tries to phone home to China and send data. Short of cutting off access via a firewall there's not much you can do to disable that "feature."

As for the composite camera's, you'd need a capture device and last time I tried looking they weren't that cheap or useful.

One thing I'm considering is seeing if I can sort out the interface on a wifi capable dash cam I have (Yi dashcam off Amazon, $50 and it's pretty decent). You can live stream the feed while it's recording over wifi, but that is using their app. I doubt it's overly complicated though and wonder if I can setup a Pi to connect to the dashcam's wifi and pull in the stream. At the very least I could have it automatically back up video to a larger storage device since the SD cards can only go up to 64GB in that camera.
 

jeegro

Adventurer
That's a good point. The Pi is great, but they are limited, and end of the day its just a computer running linux. There's probably something out there a bit bigger, with 4+ USB channels that would be better suited for the task... just need to watch out for power consumption.

The other method is to daisy chain Pi's, but ensuring 4+ Pi's are booted up and running correctly 24/7 is wishful thinking.

Maybe there is a separate device the Pi can hook up to, with its own CPU that can process all the video data. I don't know.. haven't found anything yet.

As for the dashcam, integration with the system would be cool, but I think its just that - cool - and not needed or all that useful. Best leave that as its own off-the-shelf standalone system IMO.
 
Lose the battery isolation diode on the front end. Simply monitor battery voltage and use a relay to recharge that battery. You are only talking a few amps and simple bulk charging scene will suffice. You need to create a voltage divider to get the battery voltage down to 3.3 volts Max for the Analog input. When battery voltage gets to either low or high programmed set points you either turn on or off relay. The voltage drop using just a diode is too much loss.

Interfacing to the outside world digital signals needs isolation to protect the processors. If monitoring on/off signals (digital signals) inputs use an opto isolator. If controlling the outside world digital signals either on or off use an opto coupler to drive either an N or P channel Most for the high voltage signal.

Instead of using two processor scheme for processing power take a look at UP or Udoo boards.
 

rayra

Expedition Leader
Needs more Cylon

/neat idea. Keep meaning to dive into messing with Raspberry Pi. Have an idea to build a home theater media PC with a Pi3 with wifi/bluetooth and a small 4Tb drive and embed the whole thing in an art object. Put my movie and audio collection on it.

/and speaking of anthropomorphized computers what I really want to do is embed all that in a small scale model of the W.O.P.R., complete with blinky lights.

 

Recommended books for Overlanding

Don't Go There. It's Not Safe. You'll Die.: And other mor...
by Jared McCaffree, Jessica Mans, Kobus Mans
From $19.99
999 Days Around Africa: The Road Chose Me
by Dan Grec, Dan Grec
From $19.95
Overlanders' Handbook: Worldwide Route & Planning Guide: ...
by Chris Scott
From $29.95

jeegro

Adventurer
Interfacing to the outside world digital signals needs isolation to protect the processors. If monitoring on/off signals (digital signals) inputs use an opto isolator. If controlling the outside world digital signals either on or off use an opto coupler to drive either an N or P channel Most for the high voltage signal.
This one went over my head. I was planning to use GPIO pins to toggle a relay to an alarm/light that receives its power elsewhere. Sensors can probably be powered off the board just fine.

Instead of using two processor scheme for processing power take a look at UP or Udoo boards.
Thanks for the tip on Udoo boards. Much more capable, with arduino built-in. Awesome! Still.... only 3 USB ports though. And googling around on multiple-camera setups yields not-a-lotta.
 
The GPIO pins can NOT supply the current necessary to handle the relay. Trying to drive relays directly from GPIO pins will kill the processor. You need to use the GPIO pin as a driver. Drive an optoisolator then either a transistor or mosfet to handle the current requirements of the relay coil. Try to use relays as little as possible. They are mechanical and have limited life span.

Sensors will need to be fed from the power supply feeding the board not from the board itself. The boards may not be able to supply the amperage needed by the processor and the sensors combined. Remember the the power circuits on the board are designed to supply the on board components plus small amount of interface requirements.
 

jeegro

Adventurer
Thanks, that makes sense now. I forgot to think about the voltage differences. I'll probably take this project slow and try to understand how to actually build circuits properly. I remember messing with RadioShack kits when I was a kid, but I didn't really learn anything as I'd just follow the project tutorials and never actually understand how/why/when to use certain components like resistors/transistors/etc.
 
Top