beginner with theoretical knowledge needs guidance for practical projects

Discussion in 'The Projects Forum' started by VVS, Jul 22, 2007.

  1. VVS

    Thread Starter Active Member

    Jul 22, 2007
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    Hello, I am very new to this forum and harldy have any idea .
    I mean I have quite some theoretical stuff of physics and electricity and magnetism etc at high school level. I am going to study EEE, but as I said I am only have theoretical knowledge. So I decided that I am going to work on my practical knowledge during my holidays and I'd like to start with building a robot, but I have noooo idea where to start what I need etc.
    Could any of you please give me some advice where to start? That would be really kind.
     
  2. hgmjr

    Moderator

    Jan 28, 2005
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    If as you say you are just beginning to get into electronics then I think you would need to start off with the simple and gradually progress to the complex.

    I think a simple robot kit would get you off to an easy start and introduce you to the things that you will need ot know to advance to the next level.

    I recommend you visit www.solarbotics.com and pick a B.E.A.M. robot kit to build. A "pummer" or a "photovore" are interesting starter kits.

    You will benefit from some soldering experience. If you have none then this will be a chance for you to begin picking up the skill.

    hgmjr
     
  3. SgtWookie

    Expert

    Jul 17, 2007
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    Here's another site for robotics:
    http://www.parallax.com/html_pages/robotics/shop/robo_comparison.asp

    They have some interesting projects for whatever you feel your level is.

    I have a couple of their Basic Stamps that I've played around with. Their documentation is quite good, and the Stamps I bought (BS2 and BS2sx) have a wealth of features. You could probably find more economical kits, though.
     
  4. VVS

    Thread Starter Active Member

    Jul 22, 2007
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    thanq guys! thanq very much!

    the prob i live in austria, and i think those kits would be really expensive if they got shifted to here. can i simply start building with the help of a book and single parts bought in an Electronic Shop here?
     
  5. cumesoftware

    Senior Member

    Apr 27, 2007
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    I suggest buying a breadboard, since you may use it in most, if not all cases. You don't need to solder and the breadboard alows you to reutilize components from other projects. Normally it costs about 5 Eur. Google for "breadboard" or "solderless breadboard".
    Also, I would advice the book "Electronic Principles" from McGraw Hill. This is an excellent book written by Malvino and is easy to understand, and so, suitable for beginners. You may find it in a library.
     
  6. SgtWookie

    Expert

    Jul 17, 2007
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    For parts, you can scrounge around for broken printers, floppy drives, computers, TV sets.

    Printers have stepper motors for positioning the paper and the print head, along with guide rails for the print heads. These can be very useful in other projects. Very frequently, you can find the part number still on the motors, so that you can look up the datasheet on the Internet. Floppy drives have very small stepper motors that move the read/write head carriage.

    Old computers are a great source for power supplies, ribbon cables and connectors. It doesn't take much to convert a computer power supply to a bench supply that's perfectly adequate for digital experimentation. They're not so good for linear circuits, however. Laptops have large batteries in them.

    Busted TV sets are good for salvaging various components; electrolytic capacitors, Ziener diodes, inductors, resistors, transistors, and various transformers. I found a discarded LCD television sitting on the curb the other day that had a broken screen - everything else was in good shape. Free is hard to beat!

    One thing you'll need for sure is a microcontroller, because any kind of robotic device will be much easier to control via a microcontroller - otherwise, you'll have to fiddle around with a great number of discrete components.
     
  7. JohnnyD

    Well-Known Member

    Aug 29, 2006
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    I found this site really usefull for teaching the basics. It has really good interactive demonstrations of logic gates/flip-flops, etc.. as well as all the essential basics.

    http://www.play-hookey.com/
     
  8. JohnnyD

    Well-Known Member

    Aug 29, 2006
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  9. VVS

    Thread Starter Active Member

    Jul 22, 2007
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    man o man! that is soo great! :)
    thanq JohnnyD, SgtWookie and cumesoftware

    i have decided that the first project will be building a RC car.:D
    there are a few difficulties of course but i will try to solve them mysefl.
    after all that's all the fun of it, isn't it?

    My younger bro already got an "electronic project lab" LOL http://www.laserballs.com/ee2.jpg
    but i think I'll buy a breadboard cause it is much easier to use.
     
  10. VVS

    Thread Starter Active Member

    Jul 22, 2007
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    oh yeah and i have one question:

    all this circuits i mean HUGE ones. do u understand these thoroughly like kind of read it or just build it without thinking?
     
  11. hgmjr

    Moderator

    Jan 28, 2005
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    You have chosen to make a very ambitious start. There is no doubt that you will have a lot of challenges that you will need to tackle in implementing a Radio-Controlled Car.

    You will need to be familiar with things like:

    1. Batteries
    2. Motors
    3. Radio Frequency circuits (transmitters and receivers)
    4. Servos
    5. H-bridge motor drivers
    6. Microcontrollers (hardware and software)

    Just to name a few topics that you will need to understand.

    Patience will need to be your constant companion.

    AAC and its members are here to assist you with this undertaking as best we can.

    Good Luck,
    hgmjr
     
  12. SgtWookie

    Expert

    Jul 17, 2007
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    Well, sometimes it's not really necessary to understand everything in minutae - however, you will learn much more if you figure out how to "break things down" into smaller and more understandable modules or functional blocks. Otherwise, when something doesn't function as desired, you'll have quite a time just figuring out where to start looking for the problem.

    If you just build things without thinking, you will more likely than not let the smoke out of a critical component. :eek: When the smoke gets let out, it ceases to function correctly, if at all - along with stinking up the place. :p It's plenty easy to let the smoke out of a device even if you ARE thinking about what you're doing.

    You'd really have a much easier time of it if you started off with a kit project.

    With that said, you should consider something very basic: a power supply. Find a junked or unused PC with an ATX form-factor power supply, and convert it to a bench supply. That's a pretty easy beginning project, and there are several how-to pages on the Web for doing such a conversion.

    Here's one: http://web2.murraystate.edu/andy.batts/ps/POWERSUPPLY.HTM

    Another: http://www.wikihow.com/Convert-a-Computer-ATX-Power-Supply-to-a-Lab-Power-Supply

    If you don't mind the possibility of crashing your computer, you could go the cheap route:
    http://www.wd5gnr.com/power.htm

    I made my own version of ATX adaption. The +3.3v and +5v of my supply are capable of putting out in the neighborhood of 20A each, whereas the rating of the banana jacks were 10A - so, I doubled up on the jacks, and installed them on an external aluminum plate. Several LED power-on indicators, a switch and a plastic-laminated inkjet-printed label, and I was done.

    Also, for each voltage output jack, I also installed a matching ground jack, and I'll aways use them in pairs to avoid overloading a single ground terminal.

    Once you have that built, consider which microprocessor you want to start with. It's my understanding that the PIC uP's are quite inexpensive, but they're somewhat limited in their capabilities.

    Oh, the stepper motor and associated hardware from a 3.5" drive could be a good candidate for your car's steering. ;)
     
  13. VVS

    Thread Starter Active Member

    Jul 22, 2007
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    woooooooooo!

    thank you very much SgtWookie and hgmjr.
    Okay then my first project will be transforming a PC power supply into a bench power supply. The only problem is I haven't got any unused PC.
    For the RC car will I really need a micro-controller?
    thanq again for ur support!
     
  14. SgtWookie

    Expert

    Jul 17, 2007
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    Part of the joy of fiddling with electronics projects at home is being a scrounger ;) SOMEONE that you know has a PC that is either dead, or that they've replaced with a newer model and no longer need.

    Your next step would be to find out if there are any salvage places around that have surplus electronics or computer repair shops that might have an inexpensive computer power supply laying around for you to acquire. It doesn't have to be fancy - just working. I grabbed one out of a junk heap that had a blown power resistor - cost me $0.35 for a replacement. But troubleshooting one of these might be a bit tough for a "newbie" such as yourself - try to get one that's already working. ATX supplies need 115/230v, an enable signal and a load in order to function properly; you'll find out more about that in the links I've posted above.

    Read through the how-to's, decide which is the best one for you to build, and then put together a list of parts (BOM, or Bill of Materials) that you'll require in order to complete the project. Sometimes you can find good deals on items locally - but often you'll need to scour the Web.

    As for the R/C car - well, using a microcontroller will make the project a great deal easier to build and much more compact, as the ability of the microcontroller to execute arbitrary commands replaces a potentially enormous number of discrete components. If you make a small mistake with a microcontroller program, you can fix it with program updates. If it's a logic mistake in discrete components, you may have a lot of unsoldering and re-soldering to do, along with re-engineering your printed circuit board. You don't HAVE to use one - but if you didn't, you would be a glutton for punishment. ;)

    Happy hunting :D
     
  15. VVS

    Thread Starter Active Member

    Jul 22, 2007
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    thanq sgtwookie!

    Okay I am searching for that supply.
    Simultaneously I will think about the RC car.
    Now that I know that I need a microcontroller for the RC car I need to know which one and what skills I need. How much do you suggest spending for a micro controler and tools (I guess one needs some software for the pc in order to program the micro controller won't i? - this question might sound stupid: A PIC is a micontroller isn't it?)
    I guess I need to be able to do some programming won't I (C##?).
     
  16. SgtWookie

    Expert

    Jul 17, 2007
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    PIC microcontrollers, from what I've heard, are quite inexpensive, and are easy to connect up to your PC's serial port with just a bit of wiring and a few 10k resistors. I believe they're programmed in PIC Basic, which would be vaguely similar to the basic language that came with older versions of Windows - with certain functions unique to that implementation, of course - and it wouldn't be the entire language, either.

    You can find more information using a search engine.

    I have a couple of Parallax's Basic Stamps (also microcontrollers); a BS2sx and a BS2p, along with a "Board of Education" adapter; has a miniature breadboard, sockets for various Basic Stamp types, power connections, etc. - they're well documented, decent BS2 Basic language, nice tokenizer software, but they're not cheap. I spent over $100 for those items five years ago. They've come out with a Java programmable (similar to C++) Stamp since then, and other things as well - I haven't kept up.

    It would be hard to go wrong by starting out with a PIC microcontroller; you might be clever enough to figure out how to make it perform what you wish to accomplish. If not, you might have to purchase add-on products, or upgrade to a more capable microcontroller.

    Doing more research up front will save you time, money and frustration later on. ;)
     
  17. cumesoftware

    Senior Member

    Apr 27, 2007
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    I would give an advise that worked for me and kept me in the world of electronics more time than I would expect initially. Start with simple projects. Don't be ambicious and start with a too complicated one. You will have a deeper knowledge if you learn little by little. Sometimes, you must reinvent the wheel to see the concept.
    I'm saying that because a too complicated project is prone for giving up...from the project and from the subject.

    Also, don't be intimidated by other's knowledge. Being intimidated is one step to jump to too complicated projects. I think I speak for us all if I say that we were novates at the subject at least once.

    A pic is a microcontroler. The most popular are the PIC16C84 or 16F84. Choose the PIC16F84, since it is rewritable (Flash memory). The "C" version can only be written once.
    You don't need to program in C# or C++ or even C. Assembly is the language. You should need an assembler to convert to machine code.

    There is an excellent tutorial here: http://home.planet.nl/~midde639/tutorial.pdf

    I've got it on paper for years, but I think it hasn't changed since.
     
  18. JohnnyD

    Well-Known Member

    Aug 29, 2006
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    that's some good advice there. I am still very much a beginner and I've found things like learning the theory of voltage dividers, all the different basic transistor circuits, resistor-capacitor charge times, the relationship between voltage current and resistance, all that kind of stuff absolutely essential.

    I have been teaching myself over this last year-or-so and am learning new things every day. I have made some investigations into microcontrollers and written a couple of assembly language programs but I definately wouldn't recommend starting learning about electronics with microcontrollers. Like anything, start with the basics first and work up. Even after my year-or-so of learning, I don't think I'd be confident designing an RC car just yet. You may feel different though so don't let me put you off.

    If I were you, I'd maybe start out working through some of the projects at www.play-hookey.com or something. It's good because it has step-by-step guides in how to assemble the circuits on a breadboard as well as excellent explainations of how things work.

    Anyway, good luck with whatever you decide to do, even the basic circuits are rewarding when you get them working and you really start understanding what's going on.
     
  19. hgmjr

    Moderator

    Jan 28, 2005
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    Since you are just beginning to explore electronics at the project level you have the opportunity to evaluate the other microcontroller families that are available to the average electronic hobbyist.

    In addition to the PIC, there is the ATMEL AVR microcontroller family. Atmel has designed the AVR to have many of the features of the PIC.

    My experience has been mainly with the ATMEL AVR microntroller series. I have been designing AVR based projects for about 18 months and I have found it to be a very flexible family of microcontrollers.

    There are several websites that are good sources of information for the AVR series. The primary website is ATMEL's website containing the AVR parametric table.

    If you decide to explore any microcontroller, you will need to have couple of things. You will need a general purpose hardware/software development board. And you will need a software programming tool.

    I am not familiar with the what is available for the PIC for these two things but I can speak from firsthand experience on the AVR.

    You can purchase the STK500 kit from Digikey for $84. You will need a power supply such as a 12VDC 1.5A power supply at around $30. OK, so $113 is a bit steep but it is a terrific value for the money. The board contains 8 switches that you can be easily conencted to the input pins of the microcontroller being used. It has 8 LEDs that can connected up to the output pins of your choosing. It has several sockets for that can accommodate a large number of the devices in the AVR series.

    Now for the good news. The Assembler software development program called AVRSTUDIO4 can be downloaded right now for FREE from the Atmel website. There is also a FREE standard C-language compiler that works in conjunction with AVRSTUDIO4 development program.

    AVRSTUDIO4 is a full software development/simulation package so that you could download the program right now and start learning how to write assembly language programs with out the need for the STK500 development board.

    You can go to the website at www.avrbeginners.net and find an excellent introduction to assembly language programming for the AVR.

    If you have problems you can come here for help or you can go to the website that is dedicated to all things AVR at www.avrfreaks.net.

    Either way you go, whether it is with the PIC or the AVR, you are in for a treat.

    Happy Learning,
    hgmjr
     
  20. cumesoftware

    Senior Member

    Apr 27, 2007
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    The BASIC stamp would be a nice introduction to microcontrolers. You can thus program using BASIC, a friendly high-level programming language, instead of using a low-level one such as assembly.
     
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