About Arduino board

Discussion in 'General Electronics Chat' started by bhaazee, May 4, 2012.

  1. bhaazee

    Thread Starter New Member

    Mar 3, 2012
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    I want to control AC devices using Arduino board. Would like to know how many devices can be controlled simultaneously using a single
    • Arduino Uno (or)
    • Arduino Mega 2650

    Since I am not a electronics guy, I am not able to understand the digital and analog pins info and hence would like to know the answer for my above query

    Regards
     
  2. MrChips

    Moderator

    Oct 2, 2009
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    As many as you wish.
     
  3. bhaazee

    Thread Starter New Member

    Mar 3, 2012
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    But, the power supply is limited to 7 - 12 V dc and 40 mA current. Assuming I use Mosfet (i think so) to switch ON/OFF the devices, beyond a certain no. of Mosfet, for sure I would be requiring some external power for Mosfets. So is it possible to use external power apart from the dc supply of the arduino?

    Also, Thnx for the reply.
     
  4. Von

    Active Member

    Oct 29, 2008
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    Aside from the on-board I/O the amount of control 'channels' depends on the interfacing scheme.

    If you just wish to use on-board I/O then look at the Arduino website (arduino.cc) for a comparison of discrete capability of the units you mentioned otherwise you could design your own using the on-board I/O as an addressing function.
     
  5. vpoko

    Member

    Jan 5, 2012
    258
    47
    Yes, you can use external power other than from the Arduino. You might have to do that if you're using devices (say motors) that require more than 5V, or just more devices than the Arduino can source/sink current for. Multiplexers can easily let you control more devices than the Arduino has pins.
     
    Last edited: May 5, 2012
  6. strantor

    AAC Fanatic!

    Oct 3, 2010
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    I think SSRs would be better for controlling AC loads than MOSFETs
     
  7. bhaazee

    Thread Starter New Member

    Mar 3, 2012
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    Thanks everyone for their replies.

    btw what is an SSR (abbreviation please)
     
  8. nerdegutta

    Moderator

    Dec 15, 2009
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  9. bhaazee

    Thread Starter New Member

    Mar 3, 2012
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    I have yet another doubt. Since my program will be hard-programmed into the microcontroller, is it possible to use my arduino to perform alarm based tasks (say daily alarms, weekly alarms, etc and these schedules will be changed at user's will) to control devices?

    Tried googling for answers. But still not convinced.
     
  10. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    yes.. there is very little along these lines that the Arduino can't do..(Sounds like a fish tank project).. Many add a RTC (real time clock) IC circuit (like a DS1307) and that can be used to setup time/date based functions,etc... Simply googling "arduino DS1307" should give you plenty of information/videos,etc..

    Frankly I'd get an Arduino Mega which includes way more I/O ports than the uno.. This will allow you to switch MANY loads without the need to incorporate multiplexing IC's or similar to expand the number of uno I/O's..
    If you want to be even cooler get the mega with the android adk.. This will allow you to use your android smart phone to control it too.. ie switch loads on/off,etc.. Or an ethernet shield to allow remote control from anywhere in the world via a web browser.
     
  11. russ_hensel

    Well-Known Member

    Jan 11, 2009
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    How many tasks depends a lot on the desired response time and programming skill.
     
  12. bhaazee

    Thread Starter New Member

    Mar 3, 2012
    19
    0
    Got it. Thanks again
     
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