Home automation system. design ideas.

[PeterG]

G'day All,
      i am in the process of buying a home and have started to think about what i will build into it. So far i will have external weather monitoring feeding back to our home server. Outside will have normal garden lights fitted with RGB LEDS so the color can be dialled up from a controller inside the house or maybe even from a webpage on the server.
      These are just ideas i am thinking about. I have decided to design as much as possible from the ground up, without buying items off the shelf where possible. The controllers will be PIC Micros. As for comminication, i was thinking of going wireless but i do recall seeing a 'One Wire to Serial' device that would be good to use, that way i could get away with cheeper 4 core cable.
      Anyone got any ideas of this? Input from others is always good.

Regards
Peter

[DJPhil]

If you have a long driveway you could install vehicle sensing, optical or buried loop BFO.

I always wanted to set up a webcam or cheap digital camera to take a picture of the front door when the doorbell rings and feed it to an aux input on the living room tv and/or computer monitor.

I'd also intended to use CHDK with a cheap camera to make a motion sensitive camera for a bird feeder.

Just some weird ideas.

[PeterG]

The driveway idea sounds like fun. It could be set up to announce the vehicle and also take a timestamped pic. The house would need to be wired for sound for it to announce, but it is doable.

      I have sold the temp monitoring and garden lights idea to the Wife, now just have to bring her around to the new ideas...LOL

[david77]

Oh, that sounds like fun!

I have often thought about what I would do if I ever buy my own house...
My house would have to have an "engine room", somewhere where all the electrics, server, network,
telephone stuff could be installed.

1. central light control. All lights have to be switchable from a central control, thus enabling automated
switching of lights while away to deter burglars.
All lights could be switched off together by a single switch when leaving the house.

2. central power shut-off. Same as lights with all other appliances. You would never have to worry about
stand-by appliances. Everything's off when you leave the house. Could be controlled by the door lock,
when door gets locked the house assumes that nobody's in it and switches itself off.
Refrigeration and heating devices would have to be excluded, of course .

3. automated garden watering. Either timer controlled or by sensing humidity of the soil.
Could include a pump and rain water cistern to save water and money.

4. burglar alarm. Either with reed contacts on doors and windows or IR sensors in the rooms.
Can also be tied into a central server/communications system that calls your mobile and/or police.

Now it gets really ambitious:
- electric sheep: A robot device that mows the lawn
- electric house maid: A robot device that vacuums the house while I'm out. I'm thinking about a
real vacuum on wheels here, not those rubbish little Roomba thingies.

One problem you have to think about: If you ever have to sell your house this stuff could potentialy
be troublesome. I wouldn't buy a house where some madman has installed a self designed home automation
system...

[PeterG]

Well, we have just got ourselves a 4 bedroom house that we got for a great price( due to the area) one room has already been claimed by myself as my play room, with just the two of us, that leaves one room for the kids when they come to visit and one room for my Wife to do her hobby or whatever.

Look out Wilmot..LOL

[ngkee22]

I guess this is becoming a popular idea.  I have been thinking about what all could be done to automate some house activities also.  It seems like this will eventually happen and become a good business area.  If you could tie all of the home automation in with the new smart grid idea to help monitor energy usage, people may actually be interested in buying it.  It could even be extended to recreational vehicles, like motor homes and yachts.

I thought this would be a great business to start if you can get the startup money.  It would take a couple of years of hard work to get a good prototype system together though.  It could be one of those businesses where you enjoy going to work every day and dreaming up new ideas.  Almost any idea could be turned into reality, so there is a lot of room for creativity.

I think that if I could get the startup money, I would give this idea a shot and see what I can produce.

[EEVblog]

Look out Wilmot..LOL

As in Palmyra Ave Willmot?

Dave.

[saturation]

Domotics has been around for decades and pretty much has been done; the reason its not more widespread are the lack of a single standard, and that things can go horribly wrong after a lightning storm or a a high voltage transient.  You have to choose your network standard, and work with that.

Unlike PC networks, domotics interfaces 2 items that need high isolation, line voltage and low voltage digital electronics.

If you've ever worked in a building that has centralized control over HVAC, lighting, and security, far more sophisticated that you can build at home, you'll know how bad a malfunction can get.  By decentralizing your appliances without domotics, a problem in one, doesn't affect all.  If you network them together, they can all go down, or their controllers fry, and you have no appliances, lights, etc., even if power exists in the grid.

Because new standards are continuously evolving, if you hardwire you house now, chances are its obsolete by the time you finish wiring.  

http://en.wikipedia.org/wiki/Home_automation

I've used X10 since the 1980s, and I've had some passing experience with the other formats.  You can buy modules for different appliances and control them with hard wired controllers, RF, or via your PC and many ways. Its an open standard, so you can build your own and use the protocol to transmit into your system.

As the system is old and relatively low tech, it has been resistant to power transients, but it has its own pitfalls, described here.  But you can get up and running as soon as the tear open the box and plug it in.

http://en.wikipedia.org/wiki/X10_%28industry_standard%29

[PeterG]

Wilmot as in Captain Cook Drive, near Resolution Av.
We settle early next month so i am looking at ideas for now. Still have to do the new kitchen, bathroom and loo thing first. We plan on moving in about a month after we settle.

[ngkee22]

I have been reading for about a year on home automation.  I have noticed that there isn't a standard yet and that there are numerous areas where issues could arise.  I personally have some reservations on security being integrated with the systems and what all could go wrong in that area.  I have recently been reading a little on some wireless standards like zwave and zigbee (hope they don't mind me using their name on here).  They seem like they are progressing well; I have noticed some products that use their standards.

While I would enjoy a business like this, I do believe it may be a little early because of the lack of standards, but I do believe it will happen and it is getting closer.  I think the smart grid technologies will help get some standards in place, if they can ever agree.  I think that as the smart grid become reality, consumers may want to monitor their power bills themselves, and have the ability to know where they are using the most energy.  It is kind of like the fuel economy monitor in your car, if you can see what is happening, you may be more inclined to conserve.

[PeterG]

Extending home automation to include security is something that could easily become a nightmare. I don't think it will be an issue with what i am planing.

Regards

[NiHaoMike]

You can use something like CAN bus for interconnections. Or wireless.

I'm thinking about doing something similar but since I'm looking forward to alternative energy, a lot of the power distribution would be 48V DC or something. Large loads like HVAC would have dedicated inverters and there'll be a few smaller inverters for compatibility.

[TheDirty]

If you are interested in a simple wireless home network for these simple sensors Jee Labs is a good place to look.  He's got a huge long daily blog about making his own network with the RFN12B's and AVR, but there's lots of experimentation and everything is open.

EDIT: Forgot a link.
http://news.jeelabs.org/

[ngkee22]

Thanks for that information, I will have to check out the site and see what all he has done.

[PeterG]

I had a quick scan through the jeelabs site. Looks like it is something that i could use in this project.

Regards

[shodan]

X10 is unreliable but the alternative are crazy expensive
insteon at 80$ per switch is so far out the market it's in low earth orbit !!

forget 48VDC for power distribution unless you want to wire your house in gauge 0  (your wiring would cost more than the house itself, even at last year's exponentially inflated prices)

if you play around with X10 you will find it is very suitable to merge security and home automation because the same sensors that turn on your driveway's lamp or turn off your kitchen's light when you're not there are the same sensors that ready-made home security system uses, I bought one and ditched the brains for a X10 to PC controller

one thing that this thread need is http://www.google.com/powermeter/about/
it is just brilliant !!! and it's ready-made real live product you can buy in stores already at a decent price
it's a clamp-meter that reads your whole house and use signature detection to know which appliances are on when and how much power they suck and with lots of google glues give you real nice stats !! a must imho
the device to make it work ==> http://www.theenergydetective.com/

when you are done dicking around turning on lights with X10

it's time to graduate to 1-wire or I²C temp/humitity/light/pressure sensors and use all that information to control your heat pump/oil furnace, you just rip out it's dump as rocks brains/electronics and start fresh with arduino(s)   these things use relays for decision making FFS !!!

when you're done with the house you take the soldering iron to the car (it too, is massively stupid) !!!

[PeterG]

I think X10 is very limited for what i have in mind. I plan on using I2C based chips/sensors communicating over a 1-Wire system running back to a central controller. 1-Wire gives me the cable length i need and minimal current draw per device.

If i wanted something quick and easy, i would use C-Bus or similar. I am doing this for the fun of it tho.....

Regards

[NiHaoMike]

forget 48VDC for power distribution unless you want to wire your house in gauge 0  (your wiring would cost more than the house itself, even at last year's exponentially inflated prices)

The large loads will be supplied by dedicated programmable inverters next to the batteries, so there won't be much high current wiring. It actually could be some other voltage, 48V is common in some server rooms (although power distribution is limited to just that room) because it is the nominal voltage of 24 lead acid cells in series. Higher voltages would require larger battery arrays (charge balancing becomes a problem) or DC/DC converters (efficiency loss). I think for my application, 48V is a good compromise.

[andersendr]

I would pick something using the Zigbee stack.  They even have a home automation profile    I would suggest reading this book on the subject:

Zigbee Wireless Networking, Drew Gislason
ISBN: 978-0-7506-8597-9

It deals with using Freescale radios and BEEStack in this book since the author has a lot of experience with that product line.

[toftat]

Having meddled with x10 in the past, I have been moving (albeit slowly due to the higher cost) to Insteon.

With experience of both, do not go with x10. The price is right, but the functionality simply isn't there. I had significant and inconsistent issues with reliability, with very strange results... Lights that would only change state in one direction, others that would not change state at all, motion detectors that wouldn't, you name it.

One of the most frustrating things was the one way nature of the protocol. I would install x10 switches in the wall, but they can only controll the connected load. So while you can use a remote to turn the switch on, you can't use the switch to turn something remote on...

Insteon addresses both of these issues, and I am truly a convert... it might cost 3-4 times as much, but it _does_ work...

PM if you want examples, I wrote them here but came off as an evangelist..

[NiHaoMike]

One of the most frustrating things was the one way nature of the protocol. I would install x10 switches in the wall, but they can only controll the connected load. So while you can use a remote to turn the switch on, you can't use the switch to turn something remote on...

Insteon addresses both of these issues, and I am truly a convert... it might cost 3-4 times as much, but it _does_ work...

What's wrong with low voltage switches and wire? It is the control interface of choice in industrial PLC applications.

[toftat]

If I could get at the walls before they were closed up and pull the low voltage wire in then I would possibly take that route. However I beleive (and I could be very wrong) that the wiring code prohibits low voltage and high voltage cable in the same conduit and junction box, making any install either very messy, or very unlikely to pass inspection. While it can be made safe, insurance companies being what they are will jump on any excuse not to payout.

Insteon puts the signalling on the power line and the wiring issues "go away".

[PeterG]

I am looking at using low voltage wire to control the weather sensors. And wireless for the low voltage garden lights and other outside systems.

[toftat]

I will be using Insteon outlets for my outside lights, my concern is what the GFCI will do to the signal, experience from x10 suggests that it will not go well, but Insteon has out performed x10 in every situation I am will to risk it. Besides, if it doesn't work, I will put the outlet elsewhere.

[PeterG]

Insteon is not an option for Australia as far as i know. And there is nothing on the market in Australia that is reasonably priced and does what i need. As it stands now, all i need is a low voltage line/sig cable (I am thinking standard 4 core alarm cable) for the sensors and the lighting controller. The lighting controller will be communicating via serial. If i cant get the reliability i want for the lighting communication, i may have to use something like a Xbee board.

The temperature sensors i am thinking of using are the DS1821 devices. I have used these over 30m run before with no problems.

[toftat]

Oh, sorry about that! The main benefit of x10/Insteon is their ability to reuse the powerlines for communication, it is also the source of the reliability problems too (noise in the zero crossing)

If you are using serial communications you should be OK, the only recommendation I would make would be using a balanced protocol on twisted pair (rs-422 or rs-485 I think) to help with interference.

The other thing of course would be to be careful if you are interfacing with the mains voltage. In the US my biggest fear would be fire, but with 220v I think I would be equally concerned with taking a shock. I only mention it because 220v into your hand makes for an unpleasant surprise

[PeterG]

For now, i don't see me needing to switch mains power. I hope the system will run off a couple of low voltage power supplies. I have started on the RGB light inserts for the garden lights. These will be run by a PIC Micro with a 3 channel PWM to control the 3 colors running off a serial line.

I am thinking i may make the light modules addressable so i can select the color of individual lights.

[TechGuy]

Hi,
   I came across this site on a google hit searching for something unrelated. I saw this topic and joined to share some information.

I have slowly been working on a HomeAutomation\Alarm\Sensor system based upon RS-485. I choose RS-485 because if it differential signaling that that isn't sensitive to electronic noise and interference. I've based my design on the PIC 18F6722 MCU. The system is designed to be connected using a four conductor connection; two for power and two for the RS-485 communication. So far I have two modules designed; a Dual Zone Fire-alarm controller and a 4 port relay board. All of the modules will be addressable and can be monitored from a central location. Some of the modules and operate independently with out a master controller (such as a the fire-alarm module)

The Dual Zone Fire Alarm Controller support four wire commerical smoke dectectors (two for power and two for signal alert). The alarm controller supports the commerical remote alarm signalling by reversing the power voltage polarity to force the smoke detector to sound the alarm (this can be used to activate all of smoke detector sounders when smoke is detect on one). Each Zone can be used to narrow down where smoke was detected. I've also included support for combusible vapor sensors that can set of the fire alarm if significant amounts of a flammable vapor is present in the air (proactive fire detection).

The four port relay module always you to control four devices up to 125V @ 5As. The relays are latched so they remain on or off without the module applying significant current to constantly energize the relay coil.

All modules can operate from 18VDC to 55VDC and are designed to use very low power. All modules include system monitor tools to monitor voltages (ie Input voltage, 5V for the MCU and other digital logic, and 12V/15V if the module used either of these voltages). It also has a built in temperature monitor. All modules include overvoltage\surge protection, using TVS avalanche diodes and Gas discharge tube devices. RS-485 Speed can be set from 4800bos to 230Kbps. (Slow speed are required for long distance connections that over hundreds to thousands of yards. Data will be transfered using a simplied packet protocol, where each device is assigned its own unique address.

Other modules are planned but I haven't started them. I just finished the four port relay module last week. Future modules will include a general alarm module to detect intrustion, from PIR, glass breakage detector, door & window switches, etc, Door strike\RFID card swipe (WIEGAND Protocol)\Keypad module, AC power sensor to monitor AC voltage and current, perhaps remote camera controller using an inexpensive SPI\I2C camera, and other sensors. I would also like to add a device switch\hub that can be used to connect multiple ports to a central controller that functions simialar to an Eithernet switch, but using RS-485. I've chosen RS-485 because it can work over much longer distances (up to about a mile) and is much better operating in high electric noise enviroments, where ethernet is limited to about 100 meters, and ethernet can't tolerate a lot of electrical noise.

i've attached a schematic of the 4 Port Relay design and PCB layout for your reference. I am not sure if this project is of interest to anyone. Schematic and PCB was created using Diptrace.

[microherb]

"Wilmot as in Captain Cook Drive, near Resolution Av."

Wow, your close to me Darkman1969, I'm just up the Rd in Crammond Blvd off Captain Cook Drive.

Did you know there is an Electronics design company in Resolution Av, if you worked there you'd be able to walk to work in seconds!

[PetrosA]

I'm going to side with the pessimists. If all you're looking to do is just a few automated things here and there like landscape lights and a driveway sensor, go for it. If you want to do the whole house, talk to a company that install automation systems for a living - if something fails later on, you want to be able to call a technician who knows a system, not second guess a custom design. I definitely agree with Saturation that they can be real headaches - no standards, older systems not supported anymore without a complete upgrade, etc. As an electrician, I'm willing to install some limited automation from well established companies, but mostly I wouldn't want it in my house.

[PeterG]

@Microherb: I didn't know there was a company that close. Good to know.

The system i am looking at building is not very complex. All i am looking for is a couple of temperature sensors and external lighting. I am also playing with the idea of a driveway car detector to trigger a "Door bell type device".

[DrGeoff]

This is something I've been doing for 20 years now. I've always designed my own system, since that's half the fun. If you install it in a modular fashion it is pretty easy to remove when you sell/move.

The first design was a low speed (9600bps) repeated RS232 design, no microcontrollers and simple 8 inputs and 8 outputs per RTU module. I used a COM8017 UART backwards. It was running in a house for over 7 years (then we moved).

Next I went for an 80C51 design with 16 inputs and 8 outputs on an RS485 link at 19200 bps. This worked well for about 6 years until the heat stresses in the roof started to selectively erase the Atmel devices I was using. Re-flashing them brought them back to life. Made a note not to use Atmel devices in this type of system again.

Then I used a PIC16F877 for an RTU with 8 inputs and 8 outputs, 4 analogue inputs and a temperature sensor using the same RS485 link and protocol, which replaced the RTu's using Atmel devices. These sat in the roof of the house for about 5 years, until the house was demolished (yes, I took them out before the dozers came through). The design for this one is available online (http://www.axtsystems.com/index.php?option=com_content&view=article&id=68:rtu401&catid=41:projrtu4&Itemid=73) for those that are interested.

Current design is a PIC18F8722 device and ENC28J60 on a 10baseT ethernet network. These RTU's have 16 inputs, 16 outputs, 4 analogue inputs, temp sensing, 1-wire, counter inputs and 2 serial ports. 5 of these sit on a network (both in the roof and under the house). They connect back to a Linux server which houses the event management system, database and web interfaces.

[DJPhil]

. . . an RS485 link . . .

I've got a warm spot in my heart for RS485.

This sounds like too much fun, I've really got to learn to program in some language or another so I can party with micros.
Right after I finish this project . . .

[PeterG]

DJPhil, i feel i should warn you, when you start to play with micros it will become an addiction. I started several years ago and my life has never been the same......LOL
Now days i look at everything and say to myself 'I can make that work better with a Micro or two'
My wife keeps me from going crazy with it tho...

Regards

[gbowne1]

There are things better than the X10 system.

Consider using a PLC system.. complete with all of the HMI panels, switches, relays, sensors, motors, etc.  There are so many options when you use a PLC for home automation, especially when it comes to HVAC.

They are selling for reasonable prices on eBay.

Consider using the GE FANUC 90-30 system or something like the AllenBradley Micrologix 1500.. or one of the Siemens or even something else.

I'm using a GE FANUC 90-30 complete with a large system but will be switching to the Micrologix.

Greg