Home automation using a PC as controller

[francis4u]

hi Tomi,
I m a final year engineering student of electronics and telecommunication.I like to do this as my project for the final year.but i want to do using wireless technology.So i request u to give all the information required for this project using wireless tech.

Waiting for ur reply

[Tomi Engdahl]

I m a final year engineering student of electronics and telecommunication.I like to do this as my project for the final year.but i want to do using wireless technology

Can you specify where specifically you should use wireless technology on the system. The controlling of the PC through SMS will give you wireless control of the system..

In addition to this the loads that are controlled on/off through PC can be pretty easily made wireless in thei way:
There are mains voltage switching modules that can be controlled with wireless remote controller. Take suitable number of those. Use the switching modules as they are. Modify the remote controller in sych way that you can connect it to PC parallel port. The simplest idea is to have a relay board connected tp PC parallel port, and relay oututs of it are wired in parallel with the existing buttons on that remote controller. When PC activates a relay, it would do the same as what switching the same button on the device would do. In this way you can wirelessly control all kinds of devices. When selecting the wireless system, it is a good idea to select such system that uses remote that has separate on and off buttons for each controlled device... The system that use only one button (press once turn on, press second time off, third time on again etc..) for controlling are not reliable on this kind of setup.. (if for some reason one switch pressing is not received properly thigns start go wrong..)

[francis4u]

Thanks for the reply.

but i think this topic is very risky for my project, so i decided to change. Can u suggest some similar topics like this one.

[Tomi Engdahl]

Some more discussion on conneting relays to parallel port
http://www.epanorama.net/phpBB2/viewtopic.php?t=2967


Here is one drawing for possible home automation system at
http://www.coolvista.co.uk/paraport2.php



Here is picture of one relay board referenced in article http://www.coolvista.co.uk/paraport2.php (picture from http://www.coolvista.co.uk)

[Guest]

hi der tomi!

what is more advantageous to use? a PPI ( programmble peripheral interface) or a relay??? and y?

ty a lot !

[Tomi Engdahl]

If your PPI ( programmble peripheral interface) refers to the I/O ICs or cards that were tradtionally based on 8255 is a general purpose input/output IC, then there is no much poin in asking "PPI or relay" question.

In very many application a relay is needed between the computer interface (this could be parallel port, industrial I/O card with 8255 PPI ICs in it etc..) and the load being controlled. The computer interfaces generally are deisgned for very low power loads, operate at low voltages, and get damaged easily. The relay between the computer and load allows you to control higher voltages (up to mains voltage or even higher), higher current (many amperes with normal relays, tens of amperes with very heavy ones) and they provideo isolation form load to computer (needed for safety reasons when dealign with mains voltage).

Almost the same type of relay interface (maybe at some cases exactly same circuit can be used) is generally used between the computer and the load being controlled no matter if you use a dedicated PC I/O card or PC parallel port for the controlling.

Here is one description of how to control mains voltage loads using industrial I/O card that has PPI chips in it. The description is from Planet Christmas web site page at http://www.planetchristmas.com/Digital.htm and http://www.planetchristmas.com/BlueBox.htm

"PlanetChristmas uses boards from a company called CyberResearch (www.cyberresearch.com). They have a series of "Digital I/O Boards" which plug into a PC ISA slot so you can control the outside world. In 2002, a 24 I/O port board (part number CYDIO24) costs $47... a 192 port board (part number CYDIO192) costs $199. They also have 48 port and 96 port versions. "
"Each of these I/O lines is connected to a solid state relay (3-5VDC input, 120VAC output... they typically cost $5-$18 each depending on the current load (I use a 7 amp rated version from Magnecraft.))"



"Each of the computer I/O lines (called a circuit) is connected to the appropriate strings in the yard. Most circuits are in groups of four or eight so chasing effects can be used. Here are some closeup pictures of a solid state relay box. To see a simple electrical schematic, click here."
http://www.planetchristmas.com/BlueBox.htm





Picture source: http://www.planetchristmas.com/BlueBox.htm

[iwalker147]

I have uploaded Pp1.exe , link on my homepage :- [url]www.coolvista.co.uk[/url] - This is a Delphi GUI, which you can use with Windows XP - you will need to unzip the file and keep the inpout32.dll in the same directory.
The dll allows access to the parallel port which would otherwise be prevented in XP.[/url]

[Tomi Engdahl]

My friend just made the following project that could be useful for anyone wantiong to control somethign with a PC:

Marko Mäkelä's electronics projects: RS-232 Solid State Rela
http://www.funet.fi/~msmakela/electronics/relay/

"I set up a VDR system based on the VDR softdevice plugin. The plugin has a suspended flag for stopping the resource intensive MPEG-2 decoding process. I wanted to connect that flag to a solid state relay, so that the monitor will only be powered on when video is being displayed."

"The hardware is very simple, consisting of a solid state relay, a fuse, a switch and some cables."



"The solid state relay is very simple to connect. When there is a positive voltage between the control terminals, the load will be connected."

"It is fairly easy to control the RS-232 port from software. Most modern systems implement the POSIX termios interface. Microsoft Windows has fairly similar functions, but they are named in a different way."

"You can download the example program as bitbang.zip. It contains the C source code for POSIX termios and Win32 and a Win32 executable."

[Toni]

hi der tomi??? arent PLC are expensive one's????

[Tomi Engdahl]

arent PLC are expensive one's????

The price of PLC devices vary very much on the features.
The cheapest PLC units at Finparttia http://www.finnparttia.fi/ catalogue cost around 100 Euros (not including sales tax). Typically the price for a small PLC logic should ne around 130-400 Euros range. In those pice ranges we are talking about something like 8-15 digital inputs, 4-9 relay outputs and maybe something more (few analogue inputs on some models foe example).
Large PLCS with more inputs and outputs cost more.
The price tenst to increase as the number of inputs, outputs and features increase.

[toni]

what is the advantage of a wired home automation than wireless?
and which is more advantageous?

ty

[HWman]

what is the advantage of a wired home automation than wireless?

Wired automation when properly impelemented is generally more relaible then wireless systems. All the wireless systems are subject to possible radio frequency interference. As most wireless home autiomation systems use crowded unlicensed frequencies, their reliabity is not always the best. If there is enough radio interference near your house at the frequency your automation system uses, your wireless system will not work anymore at all or works very poorly.

Generally devices with wired interfaces are cheper than devices with wireless control. So the devices itself are cheaper. The cabling in wired system is another expense, which varies greatly of you need to install completely new wiring or if you already have an existign wiring that can be used with the system.

The price of wireless and wired systems vary. Generally if you have suitabl existing wiring that can use or do not have to install lots of wiring, wired system will be cheaper than wireless alternatives. If to use wireles system you would need to install lots of expensive cabling then in some cases wireless can be a cheaper option.

[Electrodoc]

Wow this thread is busy, I'll post my reply in the root of "PC and Computers" I'll Be Back in a bit with the shortcut to paste.

[Visitor]

Wow this thread is busy, I'll post my reply in the root of "PC and Computers" I'll Be Back in a bit with the shortcut to paste.

I did not see your posting and there has been several days from you rmessage that you will post to root of "PC and Computers".
When do you plan to post that message ?

[Electrodoc]

Hi,
Had every intention of posting.. Wrote a long essay about Interfacing the parallel port but decided i needed a picture for graphical representation. clicked search to find a host to hold my Pic's.... DOH!! Where's my 3 paragraph essay gone??..

I Lost the will.. Will be back soon with the explanation i promised.. Arrgh done it again!!! only slightly differently.