Home automation system overview

It occurred to me that anyone coming here can’t see inside my head and probably don’t know my overall design for this system. Honestly, neither do I at this stage but I have a rough idea. Every development project changes as you go, especially when learning new things. Here is my design as it stands and some of the interactions in the system:overviewI will be making categories for each of these in time but for the moment here is an overview.

Input Signals

Any incoming signal into the system:

  • light switch
  • temperature sensor – control heating or cooling
  • humidity sensor – control bathroom fans
  • motion detection – automatic lighting or logging room traffic
  • light or light color sensor – detecting dawn or dust or with RGB light sensors changing inside lighting to match outside weather
  • wind speed – close windows if too windy, also for starting/shutting down wind turbine for power
  • water detection – sense if raining and close windows
  • sonic motion detection – touch-less switches for fading, like the Ninja-Shpere but far dumber
  • simple switch – on-off or momentary switches

I have played with a few of these and thought about most of them for different automated actions but the only one I have made and am using at the moment is my illuminated momentary light switch

IMAG0591While the switch works fine, apart from a slight static electricity problems (the chrome is grounded so if you are statically changed you can get a nice zap). in the programming side I can use these for single, double and triple clicks and holding scenarios.

Scene Manager

This will be the next Arduino code I will work on, it controls everything at a hardware level; in a theater it would be the lighting desk. Since this lighting setup is not just a case of “one light switch turns on a light”, there is a need for an in-between system to manage what is happening. e.g one or multiple momentary switches can control one or more lighting circuits in a fade sequence. Furthermore a switch could be programmed so that when pressed it changes the lighting in a major area, like an open planned kitchen/lounge-room from “I’m in the kitchen and want heaps of light” to “I’m watching a movie and want it dimmed” to “off” (and p.s. I want all the changes to fade in a funky fashion).

Eventually, this will interpret incoming signals, run de-bouncing code run some conditional statements and then send the fading sequence off the the dimmers for the fading.

I would also like to be able to edit configuration on these via the web interface so I can run more complicated scenes or condition.

Web Server

An input device that I didn’t mention before is mobile devices but there is a big arm of this project that will be doing just that but instead of writing an Android and a IOS app, I will host a web server that serves some nice cross browser front end code and use JQuery AJAX to talk to a PHP/postgres back end. Any mobile device will then be able to use the system but I will need to think about security a little more thoroughly that I have at the moment; I don’t want to give everyone that comes to the house the ability to change lights let alone other systems that want to have hanging off (automated Auqaponics greenhouse for example).

Power system

This will have to be done soon as we have had two power outs recently and it drives me crazy, I also have my water pumps on 12VDC so no power means no water either. My thinking with the power system does, and will do for some time, go round in circles. The major draw back in any off-grid setup (I’m not actually off-grid as I have 3phase) is energy storage, this was the key factor in my getting mains power int he first place over a full off grid solar-bettery-inverter setup…the cost of batteries is too high and their life span too short. Anyway there is no point in installing solar panels if fist you don’t look at what is using your power and looking at ways to reduce it, I’m aware that starting with lighting won’t make a massive difference in the bill but it is the start of bigger things.

Don’t wish to brag here but I have an abundance of space, sky and wind living on 100 acres. My plan for the power system is to have a solar array (12VDC or 24VDC) feeding a battery bank that feeds the Arduinos and some other key devices I have (like the water pump). Also adding to the batteries would be a wind turbine, I like the savonius setup using a washing machine Fisher and Pickel SmartDrive motor. Also having a mains charging feed if all else fails.

LED Dimmers

16 channel LED PWM dimmer, WiFi or wired that do the heavy lifting of the system. Thinking further out, I could make a 240VAC version that talks to the controller in the same way but switches mains power with solid state relays, or if someone want to they could make a TRIAC version for AV dimming. I should point out that the dimmers can be used for more than LED down-lights, I have LED strip lighting working nicely (5050) and any 12VDC device could be plugged in. I have limited each channel to 5A bu means of a fuse but the MOSFETS can handle up to 33A continuous but I would upgrade the internal wiring in the dimmer and give the MOSFET’s a heat sink before doing this.

12V LED down-lights

Any 12VDC device can be added really, the dimmer output could be hooked to a separate box to control 240VAC if required but at the moment I am using 15W (5x3W) warm white MR16 downlights.

2 thoughts on “Home automation system overview

  1. I’m also tinkering with the Arduino to do some home automation. However I’m not nearly as far down the line as you.

    I’m busy now to automate my son’s bearded dragons house. What its doing now, is to monitor the temperature and then switch day, night and uv lights on and of as appropriate. I’m busy now with the next step be able to remotely control and monitor it. I will also want to know about power failures, so I’m very interested in how you want to do your power system.

    After this project I want to do some light controlling. I will closely follow what you are doing. Maybe I can get a tip or two?

    • For sure, I am still thinking about the power system as it will be a little tricky. I would love the whole system to have a 100% up-time (never shutdown fully) but doing this is almost impossible. Also dealing with the VDC currents needs some though as these could be quite high if everything is on at the same time. I think once I have the first dimmer finished then I will get some proper amp meter tests going (maybe get the arduino to log it) and work out some hard numbers. My wish list for the power system though is to have batteries as the primary supply (also great for smoothing the power out a little), solar and wind charging and then a mains charger if the solar and wind isn’t providing enough.

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