Coffeehouse Thread

20 posts

Hobby electronics programming

Back to Forum: Coffeehouse
  • sysrpl

    Has anyone here done any hobby work with electronics and micro controllers? I was wondering how hard it would be to program appliances like this ice cream maker.

    I figure the computer controlled part of that setup could be built using an arduino and one of the many cheap and small touch screen LCDs available today.

  • MasterPi

    I took a course on making gadgets a while back. It's not too difficult...you just need to read a lot about how to set up any special actuators you use (like a touch screen panel) and you have to familiarize yourself with the chosen microcontroller. Arduino is a good starting choice. It also depends on at what level of electronics you want to get into...you could easily buy larger macro parts that take care of a good portion of the complexity (get a mini computer, a touch screen, an arduino board that responds to usb signals) or you can assemble most of that by yourself.

  • PerfectPhase

    if you want to try something like that ice cream maker and don't have a strong electronics background, the .Net Gadgeteer is worth a look

    http://www.ghielectronics.com/products/dotnet-gadgeteer

    There are lots of handy modules like Relays, Touch screens etc that can make putting simple things like that together a breeze

    http://www.ghielectronics.com/catalog/category/274/ 

    http://www.ghielectronics.com/catalog/product/327

    http://www.ghielectronics.com/catalog/product/364

    http://www.ghielectronics.com/catalog/product/376

     A selection of the above parts will be living under my Christmas tree for the next month, make all the lights flash Smiley

    If you have stronger electronics skills there are many, many other options out there these days.

  • BitFlipper

    I used the Netduino previously. Worked quite well and was easy to program using VS and the .Net Micro Framework.

    One of my projects was replacing the microcontroller on this automatic cat litter box. I renamed it the "TurdMaster 2000".

    The original problem was that my cats don't quite uhm, cover up when they are done, and the original design called for the feline to cover up before leaving the litter box. It would then sit for 7 minutes until the product was "baked" and then go into its roll action that would dump it out at the bottom.

    My updated design changed it from Bake 'n Roll to Shake, Bake 'n Roll, which resolved the design flaw in my case. So after sensing the cat has left, it would go into a Shake mode where it would perform a few roll motions so that said product gets covered up, then lets it Bake for the required 7 minutes before dumping out.

    Unfortunately one of the cats never got used to the noise it made and ultimately I had to get rid of it. Pity as I was rather fond of the TurdMaster 2000 after all the time and effort I put into it...

  • dentaku

    @BitFlipper:  What a terribly geeky story Smiley
    I wonder if Olivier Gillet started that way?

  • Srikanth_t

    Up until few years ago, I used to dabble in freelance projects exclusively using parallax products. Nice one stop shop for Microcontrollers, Servos, Sensors, whole bunch of things.

  • Bas

    , BitFlipper wrote

    [TurdMaster 2000 story]

    Awesome. Smiley

    I have a netduino lying around. I wanted to get into that sort of stuff but I quickly found that I don't have enough knowledge of electronics. I then bought this book to learn the basics, but found that there's quite a steep learning curve between really basic stuff like Ohm's law and more advanced things. Also, I then realised that if I bought all the things I needed for the experiments in the book I'd have to spend hundreds of euro's.

    Also I was blowing up LED's like crazy for some reason.

    It's too bad, I still have a bunch of ideas I want to try out. There's something fun about the idea of seeing your stuff work "for real" instead of just on a computer screen.

  • PerfectPhase

    @Bas: This is a pretty good book Electrical Engineering 101: Everything You Should Have
    Learned in School, but Probably Didn't
     for bridging the gap between the basics and the real world.

  • PerfectPhase

    @Srikanth_t:  I've been meaning to have a play with the Propeller chips for ages, maybe I should get round to it this holiday.

  • Blue Ink

    @Bas: I would recommend these excellent free videos from MITOpenCourseWare. Extremely well done and pleasant to watch.

    It should give you enough confidence to start tinkering or, at least, it should make reading more complex textbooks a lot simpler.

     

  • Harlequin

    , Bas wrote

    Also I was blowing up LED's like crazy for some reason.

    2v LED + 9v battery = Firecrackers Smiley

  • PerfectPhase

    @Blue Ink: OCW rocks!

  • Blue Ink

    Maybe it's way out of scope, but it would be really great if our friends from Coding4Fun were willing to cover some basic electronics. I'm thinking of an open series (the "1 of n" variety used by STL) covering really simple things like driving higher loads, powering LEDs, using relays, basic sensors.

    Complete projects are nice, and there's a cartload of precooked modules and shields out there, but trying to make your own hardware can be frustrating at first (and smelly).

  • Maddus Mattus

    , Bas wrote

    I have a netduino lying around. I wanted to get into that sort of stuff but I quickly found that I don't have enough knowledge of electronics. I then bought this book to learn the basics, but found that there's quite a steep learning curve between really basic stuff like Ohm's law and more advanced things. Also, I then realised that if I bought all the things I needed for the experiments in the book I'd have to spend hundreds of euro's.

    If you need anything, I have a community college and a bachelors degree in electronics Wink

    Also I was blowing up LED's like crazy for some reason.

    Too much current,.

    Say you have 5V output, a LED (which is basically a diode) takes 0,6V. You are left with 4,4V. Your LED probably needs about 20mA. So you need a resistor to limit the current.

    4.4V / 20mA = 220 Ohm resistor would do the trick.

    It's too bad, I still have a bunch of ideas I want to try out. There's something fun about the idea of seeing your stuff work "for real" instead of just on a computer screen.

    Run them by me, always fun to tinker!

  • Maddus Mattus

    @Blue Ink:

    Digital electronics is not that hard, it's either 0, 1 or an illegal value.

    Analog electronics is HARD.

  • BitFlipper

    @Maddus Mattus:

    Agree with what you said, other than LED forward voltages are typically closer to 2V - 3V, much higher than the forward voltage of regular diodes.

    I also have a BS in electronics and used to be heavily into all sorts of electronic circuits. I've since switched to software development but my dream job is one that combines electronics with software. Unfortunately every time I look into those kinds of jobs, I find them to be few and far between, and they don't seem to pay anywhere near what a software development job pays.

    Actually I used to love analog electronics, and designed and built all sorts of weird and wonderful things. I had a ZX Spectrum 48 and designed and built an 8-bit successive approximation ADC out of resistors and transistors, no ICs. It basically uses a series of transistors biased to turn on/off based on a threshold voltage, and subtract half the voltage if "on" and passes the remaining voltage to the next stage.

    Another project was designing and building a class-D amplifier (this was long before they became somewhat common). This is basically a powerful binary switching amplifier that can only be in one of 2 states: High or Low voltage (+50V or -50V). Then using pulse width modulation at a high switching frequency (250KHz in my case), and passing the square wave through a lowpass filter, you can get an analog signal out that can power a speaker. The beauty is that since the output transistors (mosfets) are either fully on (0V across them) or fully off (0 current through them), the theoretical power loss is 0 Watts (since power is volts x current). This means you can have a very powerful amplifier using no or very small heatsinks, and have it be very compact.

    My 1st microcontroller project was an 8051 driving a bunch of large 7 segment LEDs allowing you to feed MIDI into it where it would show you the song position in realtime. The idea was to mount it somewhere in a recording studio and then everyone can see exactly where in the song the current recording was at.

    Ah, those were the days...

  • Maddus Mattus

    @BitFlipper:

    I hear you, I've moved to software development as well since there are few jobs in electronics.

  • davewill

    Pete Brown ( http://10rem.net/ ) would be a good resource as well.  There were a couple of C9 videos not too long ago where they seemed to turn him loose more with the electronics.  Maybe he'll be doing more either on C9 or his own site.

Comments closed

Comments have been closed since this content was published more than 30 days ago, but if you'd like to continue the conversation, please create a new thread in our Forums, or Contact Us and let us know.