Starter questions about circuits

Discussion in 'General Electronics Chat' started by KeepYourChinUp, Jun 18, 2014.

  1. KeepYourChinUp

    Thread Starter New Member

    Jun 18, 2014
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    Good afternoon everyone. I am a complete noobie when it comes to electronics and the most exposure I've ever had is changing a fuse in a plug socket. Nevertheless I do have some questions, mostly for curiosity.

    When you guys develop "devices" do you buy every component individually and solder them into a circuit board, connect it upto a computer and program the hardware or is it more general than that? When I told my mum I was going to build my own computer, she laughed because she didn't really understand that you just buy the components and plug them into a board.

    The point I'm getting at is do you have to "invent" your own parts or is most of the stuff already built? Close to where I live is a university that has a computer science and electronic engineering department. I went in there and used their equipment (sshhh!) and they had these small ARM controllers connected to computers and with the aid of some books from the library, I managed to program one of the controllers using C and eclipse. The controller had an LCD display and some lights and I just made the lights turn on in a certain order and made the LCD display countdown from 100 and just very basic things.

    [​IMG] this is what it looked like.

    Anyway sorry for going off on a tangent but basically my question is do you guys buy pre-built boards and just change the code or do you literally build the boards yourself? With the transisters, the little batteries, the soldering, all those tiny little parts on the board and do god only knows what....
     
  2. tshuck

    Well-Known Member

    Oct 18, 2012
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    There are many factors that go into a design: cost, time, availability, ability to repair, and volume just to name a few.

    Any and all of these can decide how one might approach designing a 'device'.

    As with all things in engineering, the method to designing a board is a firm and unwavering "it depends".
     
  3. BobTPH

    Active Member

    Jun 5, 2013
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    The answer is yes, and yes. Sometimes we use pre-built boards, sometimes we make our own and solder all those tiny components. Depends on what we are trying to do.

    "Building a computer" can mean many different things. At the low side of difficulty, is buying a motherboard, case, power supply and peripherals and putting them all together. On the high end is designing at the logic gate level (or even transistor level), an entire CPU. In between would be buying an ARM processor and various other chips and making our own board and soldering all the parts. Any of those would be only as a learning exercise, since you can buy a Raspberry Pi for $40.

    Bob
     
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  4. KeepYourChinUp

    Thread Starter New Member

    Jun 18, 2014
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    Thanks for the answers so far. I remember when I opened Eclipse, the ARM board already had tons of files already programmed onto it, mostly memory allocation and assembly it looked like.

    Have you ever taken an existing circuit, like your mobile phones circuit board for example, connect it somehow to your PC and start changing code to make the phone look or do something different?
     
  5. BobTPH

    Active Member

    Jun 5, 2013
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    Yes. Look up "Android app development", or "iphone app development".

    Bob
     
  6. #12

    Expert

    Nov 30, 2010
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    My specialty is precision, low speed, analog design. Every circuit is peculiar to the job and every part is one at a time. I have cabinets full of drawers and the drawers are full of transistors, resistor, capacitors, etc. Still, I wouldn't dream of designing a mother board when people much smarter than I have invested tens of thousands of hours designing stuff I can barely understand. If there is a module available, it is usually better than I could design and cheaper than I could make it. Other than that, I use a calculator and a soldering iron.
     
  7. ErnieM

    AAC Fanatic!

    Apr 24, 2011
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    That's called hacking or cracking, and is not always as nefarious as that sounds. Many people start by modifying something already existing.

    As far as that board you saw, they are excellent things for beginners and even seasoned engineers, but especially beginners. Say you "build your own computer" (something many of us here have done): you will have an assembly of parts that may or may work when built correctly, may or may not be built correctly, some sort of program that may or may not work, and possibly a programmer to talk to this board from your PC, and that too may or may not work.

    Generally you want to minimize all the things that "amy or may not work." That is why I strongly recommend you get some sort of development board with a set of lesson tutorials to learn from.

    Once you get some expierence you can build your own computer on your own for your second project. :D
     
  8. crutschow

    Expert

    Mar 14, 2008
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    My approach is to build it only if you can't buy it (or it's too expensive to buy) as I find it very tedious to fabricate circuits from scratch, especially if it's a complex circuit. But that's just my opinion.
     
  9. KeepYourChinUp

    Thread Starter New Member

    Jun 18, 2014
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    Thanks for the post. This is what I mean though, when people build their own computer, they don't really "build" their own computer... That would require building your own CPU, your own graphics card, your own power supply. The list of materials to build your own computer surely runs into the thousands.

    Anywho I think it would be quite nice to buy one of those ARM boards, pre-coded with all the stuff needed to make it turn on but it's upto me to code it so that it does something. Maybe I could code it so the LCD displayed the time. There, I've just made my first digital clock lol.

    What book do you recommend for programming ARM boards? I think something I would really like to get into eventually would be to take a fully working iphone or some kind of smartphone and change the way to phone works, make the phone do something it wouldn't otherwise do.

    Don't take this the wrong way it's simply an example but in movies where they turn mobile phones into bomb detonators lol. That is pretty cool.
     
  10. #12

    Expert

    Nov 30, 2010
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    Using a phone ringing for a signal is so simple that you don't even need to crack it open. Set your sights a bit higher.;)
     
  11. sirch2

    Well-Known Member

    Jan 21, 2013
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    Look up "Raspberry Pi" it is a £25 Arm based board with loads of online support and a lot of peripherals.
     
  12. BobTPH

    Active Member

    Jun 5, 2013
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    +1

    Bob
     
  13. MrChips

    Moderator

    Oct 2, 2009
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    Do I build using components or do I buy ready made boards like the Raspberry Pi?

    I do both.

    I look at the application and then decide what is best. Most of the work that I do is custom design. There isn't a board available that does what the specifications call for.

    Hence I design with components from the ground up.

    My latest project requires 25 fast processors with timers all synchronized. There is no board that does that. I have to make the board myself using ARM MCUs.
     
  14. wayneh

    Expert

    Sep 9, 2010
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    You can do a lot quickly if you don't "waste" time making things yourself that you can readily buy. (Many folks enjoy making things, so it's not a waste of time.) I mean, would you spend the next month building yourself a bluetooth module that you can go buy for $20? Probably not.

    Sometimes you need something that just can't be found or hacked from existing products. That's when you need to consider if it's worth your time to build something. Designing and building is very time consuming and you have to enjoy the process.
     
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