Where To Start In DIY Electronics? 301
pyrosine writes "I've been thinking about this for a while and have no idea where to start. I have little or no previous experience in electronics — just what is covered in GCSE physics (wiring a plug and resistors — not much, I know). The majority of my interest lies in the wireless communication side of the field — i.e. ham radios and CB — but I am also interested in how many things work, one example being speakers, simply to better understand it. I would preferably like to start with some form of practical guide rather than learning the theory first, but where I would find such a walkthrough eludes me."
Re:Forrest Mims (Score:2, Insightful)
I started with a marine radio receiver kit from HeathKit. Don't know if they are available anymore, but it was more engrossing than a book would have been. After that project I was able to approach the written material with some context for understanding. I guess it depends on what sort of learning method appeals to the poster.
Re:Very important first step (Score:5, Insightful)
This is not a joke. It is insightful advise and it doesn't matter how many times you are told before you start, you will still learn this lesson the hard way.
There is a reason soldering iron handles are bright yellow. It will still not stop you from picking it up by the hot bit at least once...
Do what I did (Score:3, Insightful)
I come from a programming background, and I wanted to get into electronics. So I bought an Arduino, a breadboard, and some LEDs. Write some C code, compile it and throw it on there, and blinkenlights galore.
But wait! It can also read analog values. Hook up a potentiometer and a LED, and dim it based on the pot's position. Or grab a 7-segment display and map the pot to the display's 0-9.
All of these use the microcontroller, and since I already knew how to program I knew how to make that part of the circuit do what I wanted. I had to learn how to safely connect the micro and the other components together - but I wasn't starting from nothing.
I'm working through RC circuits now, which requires a strong working knowledge of resistors and capacitors and how they interact with the system. Wikipedia is your friend
Basically, take what you already know and use it as a wedge to push your way into something new. For me, the wedge was programming.
A word of caution - You should know enough about electricity to avoid killing yourself before you even start. Internalize the difference between voltage and amperage, for one. But if all you're working with is the small side of a 9v transformer, you should be OK.
Re:Math or Logic (Score:3, Insightful)
This is crap!
You will always need the analog side of electronics, even in digital systems.
As a limited example list: decoupling caps, local bus stiffeners, weak/strong pull-up and pull-down, termination, current limiting, pulse shaping, pulse doubling, one-shot generator.
Just try to implement a power supply, let alone design one, without an analog electronics understanding of how things are working and how they will work.
You really do need a good understanding of analog electronics, even in an "all-digital" world.
Re:Beware or you will be labelled.... (Score:3, Insightful)
They can't stop you. They can only intimidate you.
Make Electronics (Score:2, Insightful)
Start here : http://www.ladyada.net/library/equipt/kits.html [ladyada.net]
Probably the lowest cost, best-value combination of tools and supplies.
Start with this book : http://www.makershed.com/ProductDetails.asp?ProductCode=9780596153748 [makershed.com]
Don't be afraid to blow stuff up. Hell, in all the best books/articles I've read about the very first thing the authors have you do is blow up an LED. Get used to it.
get some old junk radios (Score:5, Insightful)
Something from the 70's - 80's. shouldn't be more than a couple bucks a piece at garage sales. Old enough to be discrete components, as opposed to a radio-on-chip sort of deal. Get an ARRL handbook from the 70's. Get a soldering iron.
If you still can't get your head around something, try asking for help at dutchforce electronics forums [dutchforce.com]
You have to stick to it, and sooner or later it all makes sense. :-)
If you have a local amateur radio club, they might be helpful. (they might just be a bunch of grumpy old men too, it depends on the chapter...)
Get yourself a Heathkit... (Score:4, Insightful)
..oh, wait...
Get yourself an Allied Radio kit... oh wait...
Get your self a copy of Popular Electronics... oh wait...
Get yourself a copy of Electronic Hobbyist... oh wait...
Forget it, just go buy a new chinese made mp3 player!
More basic stuff? (Score:3, Insightful)
I think a lot of the posters here are making some assumptions. Mims, sure, Horowitz & Hill, another good choice.
You need to find a way to just start playing. Once you've played some, you'll need to figure out how to continue in some direction. A breadboard is relatively inexpensive -- it's usually white with a buttload of holes in it. Wikipedia [wikipedia.org] can help you find it. You'll need a power supply -- something that will provide 3, 5, 9 or 12V seems most useful and common. It can be a box that'll hold a couple of AAs or a 9V, or a computer power supply (AT is nice -- ATX means you have to wire two contacts together on the plug). And, of course, wire. And, if there's wire, there's also needle nose pliers -- the Leatherman is a mainstay of those of us who remind you that you can't spell "geek" without "Double E".
Start by making blinking lights. Get a 555 timer and teach yourself how to make it flash at 1 or 10 Hz. Then get a speaker and make it go at 1KHz or 5KHz. You might have little luck with the transition between visual and audible frequencies -- little speakers below 100Hz are ugly, and you will have trouble viewing flashing on a stationary light above 20Hz. If you get a big enough speaker, and have it going at 1Hz with sufficient voltage swings, you can physically see the membrane moving. Adding a little salt or sand to it can make it easier to see that it is moving indirectly at higher frequencies.
The key is to find a way to get your foot in the door. Concentrate on circuits with a chip or two and a very small handful of discrete components -- a half dozen to start with. Don't start complicated, you'll just get discouraged. Once you've enjoyed that, you can start to think about more complex things like RF transmitters / receivers or BASIC stamp type controllers. If you can pick up a cheap oscilloscope and/or frequency generator, both are good tools to have.
And in this stage of learning, precious little should be soldered. You're prototyping exclusively. This stuff shouldn't be put together for more than a few days of playing. Okay, if you go the laser tag route, there's some merit to soldering that instead of worrying about a wire coming out in the middle of a match. Although if you know what you're doing, you can use a dozen or so parts to make a receiver and a gun can be half that (essentially a switch with a 555 timer at 40KHz is good enough for indoor play away from fluorescent lights whose plasma is / was near that frequency).
After my kids are a little older, I'm going to move onto a stamp type controller and some servos. There's a world of fun just waiting for us there.
Become a dumpster diver (Score:3, Insightful)
Really... not kidding... become a dumpster diver for electronics. Pull junk electronics out of the dumpster and open the cases. Learn to identify the parts. De-solder them from the internal circuit boards. Start a collection of parts. Throw what you don't keep (the real garbage) back into the dumpster. Avoid old televisions. They can hold a charge on their picture tube and that tube can implode if dropped. But old televisions are not supposed to be in dumpsters anymore anyway. (Take them to the GoodWill).
If you can't ID the parts, take a small picture of them with a digital camera and post the image to an AVR or PIC microcontroller or electronics web site, asking 'what is this?'.
The web is fantastic for learning electronics! Thirty years ago an unknown part could stay a mystery for a long time. IC data books could be difficult to obtain. Now just type the letter/number combination printed on the part into Google and you often can find exactly what it is and what it does in seconds. Ask a question on the web and knowledgeable people answer it at your comprehension level.
If you are interested in music, buy a few cheap guitar stompboxes on eBay and take them apart. Many hundreds of schematics are available on the web for stompboxes. And the best part is...if you mess up the circuitry hopelessly, someone will still buy it again on eBay for almost the price that you paid for it. Plus your guitar playing gets better.