next topic »

[on:]

Okay, I have experience as a programmer but not much in regards to UNDERSTANDING electronics. I have built/hand wired a couple of tube amps in the past(AX84), can use multimeter/solder etc., but I don't really understand WHY a great deal works. Needless to say, I will be studying Ohms law a great deal, when I first saw Arduino a couple weeks ago I realized that this could be a great opportunity to really learn and have fun. What I ask of you is this.

I got about $150.00 to use to get started. My goals are extensive use of Arduino with LEDs and lighting and maybe a simple, self opening box with motors/servos etc.. With electronic components it appears you can order in bulk much cheaper. Rather than a starter kit I would prefer to use my cash to get a wide range of heavily reused components in order to cut down on shipping and use economy of scale if you will.

What do I want?
Projects I would like to do...
Led Ambient Lighting.
Led Cube.(Looks deceptively hard)
Leds that react to sound (hopefully will display an EQ when more advanced)
Box that opens when button is touched.

What I THINK I need. (Which could be completely wrong)

2, maybe 3 arduinos for variety.
LEDs. in bulk. Preferably Tricolor. Would like to do a cube, running lights, ambient lights etc..What size/power/brightness etc. should I get, sources?
Resistors, in bulk. I don't know the values I need for these simple projects, but I will probably use a bunch of resistors.
Mic. Would like to have previous mentioned LEDs display an EQ, etc.
WIRE. What gauge, etc. Preferably a spool.
Pots.
Protoboard...duh.
Touch sensor/buttons. May be stretching for this, would like to build a simple box that opens when sensor/button is touched.
Servo/motors. Just a couple to open before mentioned box and experiment with.
Analog pressure sensitive sensor, for led project, etc.

Well, this post is probably uselessly long now but hopefully you all can help. I need sources for these parts as well. Also, what is the best place to really learn Ohms law in a practical matter? I have a great deal more questions so please elaborate on your answers as everyone knows more than I do.

[Reply #1 on:]

First off, for a lot of components, etc - Ebay can be a great place to stock up on parts. Next would be surplus outlets like All Electronics, Electronic Goldmine, Alltronics, etc. Use places like Digikey and Mouser for items which are "new only" or you can't get any other way. New parts aren't cheap, but sometimes that's the only way to get certain components.

Regarding learning "Ohm's Law" and such - I can recommend two great sources of information:

1) Grob's "Basic Electronics"
2) Forrest M. Mims III "Engineer's Mini-Notebooks" - http://www.forrestmims.org/

The first is a textbook - essentially the book for EE101-type courses; as such, a brand-new, current edition is going to run you about $100.00+ USD; instead, pick up a used copy, something recent (within the past 10 years will do). As a text book, it covers a ton of material, and is heavy on the math and theory; it starts out with "What is an electron" and works up from there. You will get math, theory, and practical application, all in one book. Entire chapters on what resistors, capacitors, transistors, etc are, how they work, how they are made, the math behind them, theory of circuit operation, how to practically apply them in circuits, etc. This is a book that should be on your bookshelf.

The "Engineer's Mini-Notebooks" were originally published by Radio Shack back in the 1970s-1980s - but the originals are "out of print"; new editions do exist, and tend to cram more into a thicker and slightly larger booklet than the originals. They cover a ton of topics; everything from beginner materials to more advanced circuits. This is a great series to have.

One other source might be to look into old TAB Books publications - back in the 1970s and 80s (and a bit into the 1990s, until they were bought by another publisher), they published a ton of books on a variety of topics (not just electronics). They all had the same formats and layouts; once you read one TAB book, you know how the others will look and read. They had quite a few volumes on various personal hobby robotics projects and general information (How to Build Your Own Working Robot Pet by Frank DaCosta, for instance), many on computer programming of the era (lots of BASIC, and 6502, 8088, 6809 assembler, for starters), and several on building your own computer (based on now-old chipsets and CPUs, like the aforementioned ones). Excellent sources of information, when you can find them.

While none of the above publications will answer questions you might have about the Arduino, they should be considered an essential part of your bookshelf for electronics...

Hope this helps!

 

[Reply #2 on:]

Thanks, I saw a lot of bulk everything on ebay, the problem is that I don't really understand what all the values mean.

[Reply #3 on:]

I think you are on a good path. I buy most of my common components (resistors,cap,leds,etc) on ebay from Asian sellers in bulk/assorted packages.

 I think I paid $15 for 1,000 assorted 1% resistors, that's like one cent each for precision metal 1/4 watt 1% resistors. I've also acquired similar assortment packs for small value caps, etc. You may pay more initially buying larger quantities like that, but nothing is more frustrating then not having a simple resistor or cap value required when one is in the heat of battle so to speak. Local radio shack just doesn't stock much in the way of components and are generally overpriced and lower quality when they do have what you need.

Of course before you buy a single component you should already have obtained a decent digital multimeter. Unlike reading/writing source code, those darn electrons are invisible and only a meter and/or scope can give you a clue of what a circuit is actually doing Vs what you want it to do.

Led Cube.(Looks deceptively hard)

I came from lots of electronics experience and I still found my 5x5x5 led cube project a real challenge to both build, debug wiring and finally writing the code. However I really enjoyed the project and while I wouldn't recommend it as a first project I would certainly advice anyone to add it to their 'bucket list' of future projects.

Lefty

[Reply #4 on:]

JayKay, where are you located? Udate your profile.  I buillt a High Octane last winter, and then a cabinet. Started Adruino-ing this summer (but am also an EE with lots of tools and parts all over the house). I bought a couple of big-ass transformers to make a push-pull tube amp with EL34s, haven't got to it yet.
Need to order some tube sockets and get going on that I guess.

[Reply #5 on:]

Interesting assortment of parts here
http://www.wulfden.org/TheShoppe/accessories.shtml
Maybe use this as a list of the kind of things to get.
If using LEDs  a lot, then stock up on 270/330 ohm current limit resistors also.

[Reply #6 on:]

I'm between places. I live in Ocala Florida sometimes, Nashville TN others.

For my leds and resistors, what values should I focus on acquiring?

[Reply #7 on:]

LEDs drop around 2V each generally at 20mA.
So for 1 LED from a 5v source:
(5V - 2V (led)/.02 = 150 ohm.
2 LEDs in series from 5V source:
(5V - 2*(2V))/.02 = 50 ohm
Can do similar calc's for 3-4-5 LEDs from 12V source for example:
(Vsource - number_of_LEDs *(LED forward voltage drop)/20mA = current needed
So make your self an excel spreadsheet and do up a few calcultions for the LED configurations you  might have in mind.
Generally  150, 220, 270, 330 will all fit the bill pretty good.
1K resistors are good for setting up transistors too if driving strings of LEDs in parallel and need higher current.

LEDs: The high brightness LEDs (3000, 5000, 8000mCD) are really bright on way less than 20 mA.
All kinds of colors available too.
Some examples:
http://www.dipmicro.com/store/index.php?act=viewCat&catId=511
www.superbrightleds.com

[Reply #8 on:]

You'll also want to get acquainted with LED driver chips, like the TPIC6x595  and TLC594x series.

If you're driving back and forth between Ocala and Nashville often, you should scout large cities with some tech industry along the way (like Hunstville and Atlanta), looking for electronic surplus outlets.  You probably won't find better deals on large quantities of LEDs, etc., but you may find deals on parts you need in onesies, like tools, and/or get ideas.

[Reply #9 on:]

Here is a site that might help.
http://www.electronicstheory.com/

But make your own judgment folks.

[Reply #10 on:]

Thanks for the link WillR. Completed the first 14 pages. I was shocked when I got the paralell calculations all correct. Surprise, surprise.

Will be studying.

[Reply #11 on:]

In the below site you can find electronics components of your wish and can make it reach you just by a mail.
http://tenettech.com
I work here and lot of components and development boards  are available for your research.
Cheers,
Bala