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Discussion Starter · #1 ·
I'm an embedded product designer with over 30yrs experience and I'd like to try my hand at an affordable & expandable HA / HVAC controller. I'd like to keep the MSRP in the $200 range.


The following is a rough draft of the hardware & peripherals, if I've missed something you'd like to see added (or even discarded) please comment.


PIC18F87J60 microcontroller with Ethernet


6 Relays (2 NC/NO, 4 NO, jumpers / labels for GP or HVAC RE2-7)

4 Opto Inputs with interrupts

1 RS485 or RS232 (RTS / CTS could be reassigned as a SW TX / RX)

1 RS485 or XBee / XBee Pro (Zigbee?)

1 SPI (RTCC with battery backup, 128k EEPROM html, ajax)

1 Ethernet 10/100

1 433MHz RX

1 433MHz TX

1 LM35 temperature sensor (freeze sensor)


The yet unnamed suggestions? controller connects to your LAN and could be controlled by anything with a web browser.


When this kit is done I plan on doing a 433 / 315MHz temperature / humidity sender to replace the traditional thermostat on your wall.


I'm trying to gather options, ideas before starting the PCB artwork.


This ZigBee thermostat is $600, I'd rather use my iPad and the aforementioned controller.
 

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Good luck with that...I'd personaly just wait a few weeks for HAI's RC-2000 theremostat that has Zigbee built into it. You can use that and a zigbee to IP gateway for remote access. (netgear has a router with zibee built into it)

The stat has terminals for remote temp sensors as well as a terminal for an outdoor temp/freeze sensor. My understanding is that HAI will make this stat available at CES in January.
 

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Discussion Starter · #3 ·
Interesting, just reading through the manual now. My main project is an Ethernet to RS485, 232, possibly/probably ZigBee with a handful of GP relays and isolated inputs (like a PLC). More like a JDS Stargate with Ethernet or a Sensaphone Web600 device. I personally feel that fancy display wall thermostats are unnecessary and old school, after all how many web browsers do you have in your home? How often do you adjust your thermostat? Wouldn't it be nice if your HVAC could talk to your alarm system and lower the temperature a couple of degrees automatically when your're not home?
 

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Yeah, I have exactly what you want and it's called an HAI omni.


Check it before you waste your time:

http://www.homeauto.com/Products/HAI...niOverview.asp


And yes, it is cool that when I arm my house in certain modes that my stats react.


The omni is built off of PLC architecture and is basically a PLC hiding in the market as a security based automation controller. It can handle 176 general purpose inputs and 136 outputs.


Cheers
 

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Discussion Starter · #5 ·
How much is the controller? I was seeing quotes of $1395 for an HAI OmniPro 2. It's also not open source hardware, firmware or software. I'm also not adding the old style telephone support hardware but some could be added externally via RS232 and a USR voice modem. Of those 176 general purpose inputs and 136 outputs how many are included before you have to purchase expansion boards? The spec sheet notes 8 hardwire outputs. I assume these are relays? I'll read the manual to see if what's included.


Edit: seems no relays are included but are extra cost options.
 

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Discussion Starter · #6 ·
The Web interface software is $309, since this is optional what is the default user interface?
 

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Hey Bill, I am simply trying to enlighten you that there are products in the market that perform the EXACT functions you menioned previously. And yes, they do cost money.


The protocols for HAI's devices are open and the SDK and API's are free. Anyone can develop and interface to them.


Good luck on your project. I wish you all the luck in the world.
 

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 http://www.lagotek.com/products.aspx?product=3


This is a installer only product that's similar to what you're considering.


Key features that are missing from your solution:


USB -- should have at least one USB 1.1 connector

Z-Wave -- wireless home automation interface (could be done with USB dongle)

Power over Ethernet -- should your box be powered via Ethernet

WiFi -- at least 2.4 GHz 802.11n


Also check out micasaverde.com. Their vera product can perform much of the controller functions and you might be better off leveraging that and concentrating on what's missing for flexible HVAC control. Existing z-wave thermostats are awkward to use and control -- a more open and embedded solution would be welcome.
 

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Discussion Starter · #9 ·
I've been musing about this project for a few years. I've found all the devices available are either ancient design, very expensive, difficult to program or upgrade, closed source, single vendor hardware specific. Many appear to be alarm systems that just happen to do home automation usually only if $$$ are spent on upgrades and add ons.


Open source in HA seems to be nowhere to be found. Some companies won't even let you view their manuals. An example is ELK M1 Gold installation manual is not available to the general public.


IMO There is always room for a modern, affordable and open hardware / software HA platform for the masses that doesn't require a team of engineers to get it installed and running.
 

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Discussion Starter · #10 ·
Thanks sglaser. I'm looking at the HIP200 now. Can't seem to find a price on it and once again it appears to be something not available for sale to an end user or DIYer.


USB:

There was another design that used USB but this requires a host computer to be running nearby, IMHO this is unnecessary, overkill and energy wasteful. One iteration of my design used USB and was meant to connect to a modern NAS such as a Q-NAP, Synology, WHS or even PogoPlug. Problem was most of these device don't support any USB protocols aside from mass storage. Of course if USB was really desirable then a simple USB to RS232 dongle could be connected between this device and a PC. A USB host (something that can talk to USB devices) is another ball of wax altogether and a much more complex design and upgrade in hardware. Possible though and food for thought. The very capable PIC32MX675F512H retails for $12 would fit that bill. Hmm...


Z-Wave:

I have a handful of Z-Wave gear (the remote chews through batteries like a baby with candy). I considered it once and I'll search again for an embedded module much like the XBee units offer. Else like you mentioned most of these things have a RS232 version. USB is fine for Windows as long as the drivers are available but it's near impossible to get the source framework needed to port to OS X or Linux and is almost completely non existent on many embedded microcontrollers.


Power over Ethernet:

Excellent idea. Although not commonly available for nearly all consumer level network hardware it shouldn't be too difficult to add.


WiFi:

This would add a fair level of complexity and cost if added at the board level. Since the kit has Ethernet it should work with any existing WiFi to Ethernet bridge. Linksys, D-Link, Asus and more have models for sale.

Asus WL-330G
 

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Discussion Starter · #11 ·
I've been reading through the scant information averrable on the HIP-200. Seems to be a purpose built HVAC controller with a damper control and IR blaster outputs. It's a Z-Wave device not Ethernet or USB. I could not find any pricing info as it's yet another call an installer sort of device. Any idea on it's cost?
 

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I've thought about getting one of these to play around with

HA wall wart
 

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Discussion Starter · #13 ·
Quote:
Originally Posted by jkv
I've thought about getting one of these to play around with

HA wall wart
It's evolved into the PogoPlug. Best Buy sells them. Problem is no serial I/O available, the device is basically a NAS & LAMP server. I mention it in my rant thread in this forum. The new Pro version appears to have WiFi. If it supported USB to RS232 dongles it would open up a world of possibilities.
 

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Why not build your system around a powerful PC based HA application that can also serve media, but has a feature rich IDE for IR, IP, RS232 and even USB support?


This is the FREE PC based software I use on an industrial mini-ITX computer I built:
http://www.cocoontech.com/wiki/Premise


No offense to HAI, Elk, Creston, Control4 or AMX, but they just don't have the flexibility Premise does and it's FREE!


Using the many predefined generic classes, users can make it work with any existing or future technology. For example, I use it with Vizia RF+ (z-wave) for two way lighting feedback. I also have Premise working with an Elk M1G security system.


Premise even offers a home layer so if a customer wants to switch to an entirely different lighting technology, all the customer specific code and web GUI stays intact and you just bind the new lighting techology with the home objects.


If you are serious about this, I would definitely study this free software. I think you'll find it's hard to compete with something that's free.
 

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Discussion Starter · #15 ·
Yes, that's the idea but. You still need the external hardware relays, sensors, IR, ZigBee and it would be nice if it had some autonomy. Although I'm not tackling home security it's something the box could be programmed to do with custom firmware (open source makes that a possibility)

Why not port that neat HA code to a small embedded linux server, then you don't need to buy Windows or the hardware and power necessary to run it.

A PC is a great device for humans, they usually include keyboard, mice & screens but very little external I/O. The box I'm proposing would work equally well if controlled by a PC, by itself or a LAMP server like the PogoPlug, GuruPlug, QNAP, Synology or the like.
 

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Discussion Starter · #16 ·
Lets say you wanted to use the box (hey maybe that's a good name, "TheBOX"
to sense open doors / windows (like an alarm system)


You could use 1wire sensors like the DS2401 or DS18S20 (temperature too) and embed them inside standard NO reed & magnet switches.



Or even the traditional 5K resistor could be used (a couple of those GPIOs will be A/D)
 

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Window based PC's don't need a keyboard or mouse to run, to extend the i/o ports all you do is add network based rs232 port servers and similar ip based devices. No offense, but I can already do everything you are talking about with a free program that is very open, but yes, you do have to supply external hardware like a zwave rs232 modules, networked based IR controllers etc...


Your "box" concept is also flawed. For things like IR control, why not use a local network based ir controller and communicate with it over the network? It's so much easier to install that way. Putting all ports for every device in one place doesn't always make sense... Wiring a home with extra runs of Cat6 to each room is much more future proof anyways.


Here's a few network based solutions I use:
http://www.globalcache.com/products/itach/wf2irspecs/

http://www.lantronix.com/device-netw...s/uds2100.html
 

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Discussion Starter · #18 ·
Modern Windows PCs are way processing overpowered and I/O underpowered for HA. Plus Windows isn't free either plus the home version isn't known as a reliable web server, of course Windows server would be fine or the seems like it's being discontinued HP WHS.
http://www.prlog.org/11118205-hp-has...rt-server.html

HA is an I/O intensive problem and that's what I'm trying to build. Sure there are scads of I/O extenders with all sorts of interfaces but none are open designs.


My $200 - $300 proposed controller has:


1 Ethernet 10/100

1 RS232/422/485 full flow control (+5 on pin 9) DCE

1 RS232 full flow control (+5 on pin 9, jumper selectable as RI input if using an external modem) DCE

1 ZigBee ($20 XBee S2 & $30 S2P are now ZigBee compliant)

1 128kB SPI EEPROM (possibly 256kB)

3 Relays (1 NC/NO, 2 NO)

3 IR blaster outputs

1 38kHz IR sensor (front facing, translucent plastic)

4 GPIO

1 temperature sensor (simply for freezing pipes)

12 - 15VDC power connector


It'll do and could technically emulate any of the current Global Cache product line plus much more.


It'll have enough processing power to work autonomously and is modular. Of course it can be controlled by a PC or Linux box such as the PogoPlug. It's open source design will allow it to grow beyond my technical abilities.


As for cheap but "dumb" nodes after I design the above device they're nothing saying I can't put together simple ZigBee/RS485 to IR / Relay slaves.

This was a kit I put together awhile back that was an RS232/485 IR I/O bridge.


It's an early incomplete drawing but it was made into a client product.
 

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Quote:
Originally Posted by blueroom /forum/post/19660918


1 38kHz IR sensor (front facing, translucent plastic)

???


What is that for? A box with so many wires and connections hanging from it is not sitting in plain view to want to control it with IR. You need to have an IR input jack.
 

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Discussion Starter · #20 ·
Agreed, the onboard IR may vanish in favor of a 1/8" phone jack with an IR eye on a wire, it would also be possible to have both options as an IR TSOP1138 is only about $1
 
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