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1921  Using Arduino / Project Guidance / Re: Reflective surface, alternatives to mirrors? on: March 15, 2013, 08:46:17 am
Aluminum cans are plated on the outside, generally very shiny to highlight the painted label. With paint remover and fine steel wool the label comes off and you are left with beautiful shine. Coors cans are highly silver under the label. Some few others will be brass color. I know this from modeling, the metal can be flattened and polished up nice. Not a mirror but yes reflective.

You could also look for chromed steel, even junk. A little polish and some work, pazow, mirror!

1922  Using Arduino / Programming Questions / Re: Keyboard output(Bit of a beginner) on: March 15, 2013, 08:36:03 am
If you are running Windoze then Hyperterminal can be used to send PC keystrokes directly to Arduino. Hyperterminal will also let you copy contents to the clipboard for paste elsewhere.

 
1923  Using Arduino / Programming Questions / Re: Accessing serial data stored in a buffer using a char pointer ? on: March 15, 2013, 08:25:17 am
You can set a char * to the start of a char array:

char buffer[ 32 ];
char *buf = buffer;

You can index the pointer:
buf++; // move 1 byte to the next char, if it was an int pointer it would move 2 bytes to the next int
buf--; // you can go back

You can do pointer math:
buf += 8;
buf -= 2;

You can use string (not C++ String object but C string.h) commands to set pointers to say...
find a character withing a string or a string within a string or to parse a string.

There's too many to list here when they're listed and explained elsewhere:
http://www.nongnu.org/avr-libc/user-manual/group__avr__string.html

You can treat pointers as variable memory addresses.

A valid C string ends with a NULL ( == 0 ) character.


1924  Using Arduino / Programming Questions / Re: IF temperature > 24 --> hot hot hot on: March 15, 2013, 12:21:54 am
Try reading the first post again.

1925  Using Arduino / Programming Questions / Re: IF temperature > 24 --> hot hot hot on: March 14, 2013, 08:44:02 pm
Code:
if (temperature > 24) lcd.print("Hot Hot Hot");
if (temperature < 24) lcd.print("ice ice baby!!!!');

What is it supposed to do when (temperature == 24) ?  Or maybe if (temperature >= 24) is hot?

Why not have a "Just right baby!" in between Hot and Cold? Ice is way colder than 23 C.

Code:
if (temperature < 24) lcd.print("ice ice baby!!!!');

There's something wrong with the syntax at the end of that line above. You start the text to print with " and end with '.
1926  Using Arduino / Project Guidance / Re: IR location with beacon on: March 14, 2013, 11:12:44 am
Sunlight on a wall can be picked up by simple near IR detector. The pulsed kind can handle a certain amount.
If it shows white on a CCD cam (web cam, phone cam, etc) and doesn't look white to your eyes then it's near-IR overloading the detector. A red led puts out strong near-IR light.

1927  Using Arduino / Project Guidance / Re: Record Changes in Height of Book Stack - Best Sensor? on: March 14, 2013, 10:49:21 am
But why need to supply an IR source when you have free room light? Can room light penetrate a book? If a little might get around somehow, put a resistor on the detector input so it does not let the pullup go LOW.

A photodetector needs a certain amount of light to switch full on, the books should block that if the detectors are positioned right. It is already stated that the book spines will be set right against the spacers so where do you put the detectors?



1928  Community / Bar Sport / Re: Your latest purchase on: March 14, 2013, 10:40:50 am
The advantages of strength and wear are not just theory. That cloth is just a way to go about it.

1929  Community / Bar Sport / Re: Your latest purchase on: March 14, 2013, 12:46:11 am
I've wondered about wood splinters as a cheap alternative to glass or wire. Shavings? Sounds good. I only use sawdust with glue to make putty, not crete.

The way I was first taught is a frame with layers of chicken wire loosely tied and the concrete pressed in taking care there's no air bubbles. It can get very thin and take high loads. That was 1974-75.

I see the use of 2 to 3 inch wire or glass fiber strands touted since. It can be poured, molded, and now erected dry and hosed down. The amount of handwork has gone way down.

Also at home supply stores, check out Hardie Board and Hardie flooring, especially the flooring.



1930  Using Arduino / Project Guidance / Re: Record Changes in Height of Book Stack - Best Sensor? on: March 13, 2013, 10:14:40 pm
If you drill through the wood spacer(s) that the book spines will be set against and put the detectors in there then extra light from the sides will not be a problem but a help. Ask if the box can be tilted so the spines must always sit against the spacer(s).
Why spacer with an s? If holes will be too close in one spacer then stagger the holes across two so each has every other hole, farther apart than all in the same spacer.

1931  Community / Bar Sport / Re: Your latest purchase on: March 13, 2013, 10:07:18 pm
The ribbing where the fabric is stitched forms the load bearing members of the structure.

When it is done, the shell is the load bearing part.
And wow, call it a 'bomb' shelter. But it's not proper evil genius without an underground complex.

Concrete has enormous compressive strength, good but not great shear strength and very weak tensile strength. Add wire or glass fiber and suddenly you have super-crete.

I learned wire and concrete in design school. Less than 3/8" thick welding rod, stainless steel screen and concrete easily deflected a 2 1/2 lb sledge on a 2 ft wide model. Tubing, chicken wire and concrete has been used to make ocean-going 40+ ft boats with 3/4" thick hulls (except where the 2 1/2" tubing was). The stuff just gives and flexes back. If you break it, you push the loose stuff out and patch it with concrete, which is kind of like what you do with a fiberglass canoe that's been slammed into a rock.

I have to wonder how thin the glass cuttings and concrete can go. It might work for enclosures and it might not.

Oh yeah, use driveway sealer when you're done. Concrete needs some water (the term I was given is water of hydration) to maintain bonds. If it dries out, it loses strength.
1932  Community / Bar Sport / Re: Free computer power supplies, hard drives, and CD drives on: March 13, 2013, 09:29:25 pm
Windows needs something that writes faster for virtual memory.

Dang, wish I had more cash free, those 5 1/4 floppy drives might have some bodacious steppers.

Yeah Wizdum, BB is one of the recycle stores.
1933  Community / Bar Sport / Re: Your latest purchase on: March 13, 2013, 02:25:43 pm
I've used sawdust and carpenter's glue to make light mountings. Had a neighbor who made rockets from glass cloth and epoxy but I'd have to do major re-arranging here to begin at it.

Another mix I have yet to try is glass strands in concrete.

3D printer... a dream for me. I want one that can lay fiber and wire, maybe print sockets.

1934  Community / Bar Sport / Re: Your latest purchase on: March 13, 2013, 12:02:08 pm
Well, I'm well-known for my bottom-feeding on ebay..

Because you keep telling us so! And then you provide the details to prove you're not just a bottom-feeder but an effing hero-class bottom-feeder to boot!

Tell me please, do you use any glass cloth in your epoxy work?

 
1935  Community / Bar Sport / Re: Free computer power supplies, hard drives, and CD drives on: March 13, 2013, 02:18:28 am
I hope that the parts you throw away get taken to a store recycle center. We have them here.
There's also GoodWill.

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