Slashdot Mirror
Building Your Own Glowing Cyber-Balls?
krezel asks: "So I've been drooling over the Ambient Orb, a cool little gadget 'glowing ball' that you changes colors based the 'health' of things you specify. It can do stuff like fade from red to yellow to green as your stock portfolio improves. However, being a poor college student I can't afford its $200 price tag. I've found lots of sources for super bright multi-color LED's. Cast a couple of them in some translucent resin, hook them up to a power source, and you've got yourself a cheap glowing ball. But I've yet to find any good information on how to build hardware that will let me control relays for devices like this through my serial or parallel port. Basically I'm looking for a cheap way to build a board that will let me control 4-8 relays (for each color) over my serial port, and some info on how to write the software for it. This could be a very cool project, and I plan on making the plans available, and the code Open Source, when I'm done with it. Any ideas?"
The natural target application: hook this up to correspond to the Terrorist Threat Level as published by the US.
I could see using locally-connected glowing globes this for all sorts of monitoring; stock market tracking isn't really near the top of the list. I can see having a row of stuff like this visible in or near a server room for example, showing network latency or traffic load, system load, any of a variety of things.
What the difference between this and assorted other status/alarm LED displays? These are in a translucent block and are more easily visible from a distance. Not such a bad thing.
Heck, I use something similar as a shower timer - it dims over 15 minutes, and if I glance over and it's gone out then I'm probably running late.
fencepost
just a little off
But seriously, I've always wanted something like this for work. A simple status indicator whether the cluster of machines I'm responsible for is Working Fine (green), Having Issues (yellow), or Completely B0rked (red).
Currently, I keep a persistent browser window open to a simple web-based script that checks on the status of everything and sets its background to one of those colors based on what it finds (it's quite a bit more verbose than just that should something be wrong, but that's not the point). This is fine and dandy for my use, but for the sake of being interupted during an emergency...
It'd be really cool (and actually useful) to have a separate orb that glows the same color... so the next time my PHB runs in to tell me I forgot my TPS report cover sheet.. er.. to tell me that he's noticed a problem with the site, he'll first see the big red glow and realize I'm already aware of it.
(that, and when I'm deep into a Quake match, and can't see the little window...)
http://freshmeat.net/projects/palace/?topic_id=113 %2C122%2C135
For xmms-syncing=lights via a parallel port - I've been considering doing this for a while, and the guys has great instructions
I'm more of a CS than an EE, but having dealt with the hardware side a little bit, it sounds pretty easy:
You can just steal or buy some testing / teaching equipment from the local EE department... I think things that can hook up to a PC and drive simple signals are common and cheap and allow software to interface with them trivially. My local EE department has hundreds lieing around, though I've never used one, and don't know what they're called.
Or, if you want to build everything yourself, that shouldn't be too hard either. Get a cheap programmable chip (unless you know more than I do about a serial port... it might be possible to do with a simple non-programmable chip that just latches values from the pins at the right time). I used a PIC16F876 at one point... it's basically a miniature computer on a chip, with IO designed for interfacing with things in a programable manner... it worked well, and is cheap ~ $4 or $5 (and you can get them for free if you ask... they give away lots of samples to students). I think it had some built-in module for interfacing with a serial port, but if not that should still be possibly manually, with some assembly coding. The chip didn't have any digital-to-analog converters on it that I can recall, but with LEDs I think switching them on and off really fast for varying periods of time is better than driving them with an variable signal anyway. It also was not capable of driving as much current as I suspect you want, so you'll need external amplifiers, but a handful of discrete transistors works fine for that purpose (and is dirt cheap). The only thing I can think of that you might actually have to pay for is the power supply for the whole thing. And maybe a board to soder on.
Hm... come to think of it, I don't know how to write out to the serial port on any OS more modern than DOS. But you can probably figure that out with a tiny bit of googling.
How do LEDs hold up to high frequency PWM? That sounds like a really cool idea.
Wah!
It would be easier just to take a hollow spherical acrylic lamp, put the lights in there, and roughen up the surface with steel wool or spray translucent paint on the inside. No casting needed.
All you need are the following:
1) 25 PIN MALE DB Connector (like would plug into the parallel port) - OR, probably easier, grab like a 6' or longer 25pin Parallel Printer or extension cable and chomp the end which doesn't plug into the computer off.
2) 8 superbright leds.
3) 8 10K resistors.
4) 8 2N2222 or other NPN transistors (Just go to radio shack and get a bulk package of "NPN switchint ransistors")
5) 8 "smaller" resistors. Like roughly 500 ohm, but be prepared to experiment with the value. Lower value=brighter, but if you go too low you will burn out the LED. There *IS* a formula for the smallest permitted value. I won't go into that here.
6) Perfboard to put it all on
7) 9 or 12V DC wall-mount supply (or similar).
A little background:
The parallel port on the PC has 8 outputs, on pins 2-9 of the 25 pin connector. The ground for these are on pins 18-25.
You can technically get away with just wiring the led directly to an output port, then to a resistor which then connects to the ground. Google for "parallel port led"
However, it is likely that you will need more current than the parallel port will provide. For this you can use a transistor to act as a solid state switch.
Here's a description of the schematic:
For each output pin:
1) Wire the output pin on the parallel port to one side of a 10K resistor.
2) Wire the other side of the 10K resistor to the base pin on the transistor.
3) Wire the emitter pin on the transistor to circuit ground.
4) Wire from the collector pin on the tranmitter to the pin closest to the "flat edge" on the LED.
5) Connect the other LED pin to the "smaller value" resistor.
6) Connect the remaining pin on the "smaller" value resistor to the + wire of the power supply.
ALSO, do the following:
1) Connect the ground pins (18-25) of the parallel port connector to the "circuit ground" mentioned above.
2) Connect the "-" wire of the power supply to the "circuit ground".
You can test this before plugging into the computer by plugging the DC adapter in and then jumpering between the + wire of the power supply and each output pin on the cable you are going to plug into the computer. The corresponding LED should light.
I'd recommend just doing the first led first to make sure everything works.
NOTE: YOU CAN BLOW OUT THE COMPUTER PORT IF YOU DO THIS WRONG. I HAVE NOT CHECKED THE ABOVE DESCRIPTION SO IT MIGHT BE WRONG AND MAY CAUSE THIS EVEN IF YOU FOLLOW THE INSTRUCTIONS EXACTLY.
If you need more LEDS on a given output (like 2 or 3 to get enough light), you can just connect a LED/resistor pair in parallel with the existing one (all of the LEDS are connected to the transistor, all of the resistors are connected to the + power supply connection, and each led is connected to it's own resistor).
You basically drive this by outputting data to the parallel port. You output a single byte at a time - the most recent byte is what the leds are set to on or off.
If you want to vary the brightness of the LED's you can actually do it by turning them on and off quickly in software. A simple timing loop which have the leds on 50% of the time would result in the leds being 50% dimmer than if they were just left on. Of course you have to do this fast enough so they don't "flicker" or blink.
People who don't care about their lamps having an IP address, and just want a hoopy colour-changing battery powered LED light thing, may be interested in the ones I reviewed (along with a variety of other LED lights) a while ago. There are a few products like this around now, but these ones are tough, and you turn them on and off by shaking them :-).
Now wait just a darn minute here..
Using color to reflect the state of an object?
Color-reactiveness?
Oh wait, thats only for insane people!
Bowie J. Poag
Win 9x has direct access to the ports. Win NT/XP needs you to go via the device drivers, but it's not a difficult problem - plenty of info for how to do it.
:-)
Beyond Logic
Parallel Port Central
Both the above have a bunch of useful stuff.
Also don't forget that you'll need to learn how to drive LEDs. I'm admin on an electronics board, so here's a blatant plug:-
BasicElectronics board, LED FAQ
(and kudos to David Bridgen and MacGregor who put that info together
Grab.
Okay, maybe a few basic hardware References, HI-LED, Breadboard, and Chip Products links would help.
Reference - AtariArchives Electronic Computer Projects
Reference - Electronic Circuit Guidebook Sensors
Reference - Robot Building For Beginners
Global Specialties Breadboards
Eductional Kits USA including LED kits
High Intensity (HI) LED Source Discrete LEDs, LED Panel Mount Lamps, Based LED Lamps, SMT LEDs, PCB LEDs
RF Digital Corporation HI-LED White Red Yellow Blue Green
National Semiconductor Chip Products Catalog National Semiconductor Products
PMC-Sierra Chip Products Product Directory
R.T.Nollet, Chip Products, Australia
There you go; it should be enough to get you started on the hardware. Others that are far better at software can help with some of the required programming resources. If you can afford an old logic analyzer (maybe 8/16-pin, at surplus stores) for the I/O buses they can help you optimize your code. Years ago, (when I did) I would have used, an appropriate Hex/Machine code to do a small project like this. If you and a couple colleagues/friends succeed at this level ... the lessons you teach yourselves and experience obtained will be significant ... not many universities teach at this "wide-concept" "Master-O-None, Jack-O-All" level anymore. Very few Geeks under 40 years old (I believe) would be able to do what you are thinking about even less if they have a college degree that pushed them into a "high pay/viz" specialty at a young fragile age.
OldHawk777
Reality is a self-induced hallucination.
Unaccountable leaders are masters, and unrepresented people are slaves. How do US and EU fare?
It would be a whole lot easier to go to your local home improvement store and buy a frosted, glass light fixture. Might even be able to find a small one.
It seems most of the posts involve USB or some other port from a PC. I thought some of the point of the ball... well, all of the practicality of it, at least, was that it was wireless. I know the only reason I'd ever use one is because my computer is loud and I like to have it off when I'm doing anything else in my room. To have a lamp light when I've got mail would let me unsleep my machine just when I need to.
... and of course, if someone actually makes one, I want one....
Just put the guts of an old pager in it. Then you could have the thing battery powered and completely wireless. Your server checks whatever you're interested in and fires off emails to ##########@messaging.yourpagerco.com with text messages telling the lights what to do. RED FULL, PULSE RAINBOW, SLOW GREEN, whatever... have that tie in to all the other hardware you guys came up with.
Text pagers are dirt cheap - we probably have a drawer-full somewhere. And the service is under 5 bucks a month for a single person...
-- I have nothing clever to say.
"Cast a couple of them in some translucent resin"
Yeah, like it's that easy. Have you ever tried to work with acrylic and hardener? It's a MESS. It's the consistency of motor oil and after some air exposure it starts to get sticky. Worse, it smells like paint * 100. Finally, I can guarantee that you WILL NOT be able to 'cast' a sphere. The inside of a small toy ball might be your best bet, but I have my doubts about how the mechanics of the casting process would play out.
Those discouraging words said.... Dude! Give it a try and let us know how it works. Better yet, take some time to think about clever ways to make that casting happen and maybe you can share a new and interesting technique with the rest of us. But before you start too far down this path, go buy a small (8oz) can of liquid acrylic + hardener (expect to pay $15-20 for these) and do some small experiments (more than one!) so that you get a feel for what working with that stuff is like.
Good luck and report back!
Um, you do know you can go down to WallyWorld and pick up a cheap kit. I have seen the Baby Impressions Kit in WallyWorld's craft department.
Check the CRYSTAL KEEPSAKE KIT
(I am certain you can find similar kits under different names online - GOOGLE is your FRIEND so have GOOGLE help you out)
Add in a balloon for the sphere shape while making the mold shape and pop and remove the balloon before casting. Or if you feel this will not give enough "solidness" to the shape you can fill the balloon with water, tape the end shut and when you want to remove it from the sand mold to begin casting, suck the water out with a straw.
With a little imagination a person could cast anything with just a bit of effort (using moist sand to make the mold - adding sugar to the water will give firmness when the sand dries, tamp down the sand, drain the sand, remove the positive object, if you can, then add your molding compounds, and when the mold sets or cooks or cures you can wet the sand, and retrieve your finished item.)
Please note that Silversmiths of Colonial times would use a wax sculpture of the object to be molded, then tamp some sand down in the bottom of a wooden box (to make a sand base for the model), place the wax model in the center, add fine sand carefully to fill up the area around the wax model in the box, pack the sand down gently, and then drain the water off, and then when the sand was dry they would heat up the silver in a cauldron and pour it into the open spout of the sand mold and destroy their wax model. This left a finished silver model after the silver cooled to be smoothed and polished.
Mold and object casting is an interesting art form which I suggest you folks research as you might want to try making some cast art someday.
"Face it, a nation that maintains a 72% approval rating on George W. Bush is a nation with a very loose grip on reality.