serial/parallel/usb control of appliances


Forum: water cooler
Topic: serial/parallel/usb control of appliances
started by: mikshaw

Posted by mikshaw on Feb. 04 2008,01:50
I've been googling for sites that might be able to help me understand what is needed to create interfaces to appliances that can be controlled from a personal computer, but so far have come up with little results.

Can someone point me in a direction where I might get started? This isn't something I have any knowledge about at all at this time...I know nothing about how com ports work, and nothing about creatng controllers. I'm just hoping to begin learning about these things but so far have found nothing but commercial products.

Posted by curaga on Feb. 04 2008,07:18
Depends very much on what you mean with "appliances", and which port you will use.

Anyway, have a look at the Coffee-howto at tldp.org, and the self-built Cir transmittor for serial port at lirc.org. The lirc driver also has source code for using it.

I haven't attempted any of this, but I believe you just output a stream to the data pins, using kernel functions..

Posted by u2musicmike on Feb. 04 2008,22:08
I haven't tried this but maybe using a microcontroller might work for you.  Say you wrote a program that sent a hex number to the com port to turn on a light or coffee maker.  A piece of hardware would have to take the hex number and activate a relay:  

< AVR microcontroller >

Getting a number out to the com port can be done with an echo command and redirection:



Code Sample
echo "27" >> /dev/tty?

Posted by lucky13 on Feb. 05 2008,00:02
Not sure if anything in the FAQ or wiki (I see a little bit about serial ports there) or docs in the link below will be useful to you, but I came across this the other day. It's a perl/cpan script to automate, well, a house. Maybe search through the code and see how its author does it?

< http://misterhouse.sourceforge.net/ >

Posted by mikshaw on Feb. 05 2008,02:03
Quote
Depends very much on what you mean with "appliances", and which port you will use.
I'm sure details depend on these factors, but I'm not really talking about specific projects at this point. I just can't seem to find anywhere to even start. All I'm interested in at this time is *possibly* working toward a very simple project, something like lighting an external LED by clicking something...a starting point from where I can decide if I even want to go further with it. It's mainly the basic concept that I find interesting, but I'm not sure whether it's something I want to get into.

Thanks for the links, I'll check those out soon.

Posted by ^thehatsrule^ on Feb. 05 2008,03:13
I've touched upon something along these lines, but very long ago... with the help of something like Lego.  Not sure if they were built-in or someone modded them before..
Sorry if that doesn't help you out much :P

Posted by newby on Feb. 06 2008,17:20
Quote (mikshaw @ Feb. 03 2008,20:50)
I've been googling for sites that might be able to help me understand what is needed to create interfaces to appliances that can be controlled from a personal computer, but so far have come up with little results.

Can someone point me in a direction where I might get started?

Somewhere I have xeroxes of articles about:

Building USB interfaces;

Building a pager interface;

and probably others...

If I run into them, I'll shoot you the references.

The LEGO interface and be found by tracking down the FORTH hack of LEGO.

Posted by spark-o-matic on Feb. 08 2008,02:56
You might have a look at my post in hardware. I have had a working prototype for about 6 months now.

Richard

Posted by jaygeedsl on Feb. 11 2008,09:32
Have a look at the article "Hardware Hacking Revisited"  in Linux Format Mar 08 page 57.
Posted by chaostic on Feb. 11 2008,12:53
Quote (mikshaw @ Feb. 04 2008,21:03)
Quote
Depends very much on what you mean with "appliances", and which port you will use.
I'm sure details depend on these factors, but I'm not really talking about specific projects at this point. I just can't seem to find anywhere to even start. All I'm interested in at this time is *possibly* working toward a very simple project, something like lighting an external LED by clicking something...a starting point from where I can decide if I even want to go further with it. It's mainly the basic concept that I find interesting, but I'm not sure whether it's something I want to get into.

Thanks for the links, I'll check those out soon.

http://www.diylife.com/2008/01/25/make-a-usb-color-changing-light/

< http://www.diylife.com/2008/02/02/show-pc-stats-on-analog-gauges/ >

Posted by newby on Mar. 02 2008,12:28
Quote (mikshaw @ Feb. 03 2008,20:50)
I've been googling for sites that might be able to help me understand what is needed to create interfaces to appliances that can be controlled from a personal computer, but so far have come up with little results.

Check out Chuck More's seaForth-24 processor - 24 processors running at 1 Ghz each and drawing less than one watt total.  A mini-super computer on a chip.

Now, here's a platform to port *nix to!

"SEAforth-24 Chip Profile

"Combining a 6x4 array of 18-bit processors with a powerful set of I/O functions, the SEAforth-24 chip deploys an innovative dual-stack architecture that is both asynchronous and scalable. Capable of driving an antenna directly, the SEAforth-24 wireless solution eliminates the need for any external data converters. The numerous on-chip benefits include:

  "* RAM and ROM on each core (512 words each) to break the memory bottleneck
   * Flash memory interface to ripple-load application code into cores at boot
   * Static/dynamic RAM interface to facilitate common data memory access
   * Real-time clock support in each core
   * 18-bit A/D and 9-bit D/A to eliminate need for external data conversion
   * Eleven Serial (SPI) ports, which can double as I2C, I2S, and USB ports
   * 32 Parallel I/O lines with handshaking for versatile "bit banging"
   * Scalable connectivity among multiple SEAforth-24 chips via high-speed I/O ports"

Also:

"# Forthlet Code objects that can be stored in one core but executed on others
# Automatic "sleep mode" to save processor power while waiting to send/receive
# RAM capacity for 2048 instructions; packing four instructions per 18-bit word
# BIOS-facilitated message routing to assure efficient event coordination"

From:  http://www.intellasys.net/index.php?option=com_content&task=view&id=44&Itemid=55

Posted by curaga on Mar. 02 2008,14:01
/me wants the Sun OpenNiagara T2: 8 cores each with 8 threads running at 1.6Ghz, aka 64 logical processors. And it's Sparc, so linux will run on it already..
Posted by newby on Mar. 02 2008,16:01
Quote (curaga @ Mar. 02 2008,09:01)
/me wants the Sun OpenNiagara T2: 8 cores each with 8 threads running at 1.6Ghz, aka 64 logical processors. And it's Sparc, so linux will run on it already..

That would be cool also.

_Anything_ beyond Wintel would be cool!

But, back to the main thread:  The original poster wants to

Quote (mikshaw @ Feb. 03 2008,20:50)
create interfaces to appliances


which is exactly what FORTH was developed to do.  See: "The FORTH program for spectral line observing" by Moore and Rather.

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