Having problems with chip and DC motor and potentiometer and Arduino....

Discussion in 'General Electronics Chat' started by roineust, Dec 25, 2013.

  1. roineust

    Thread Starter New Member

    Jul 2, 2013
    3
    0
    Hello!

    I have tried to build the following circuit:

    http://fritzing.org/projects/drive-motor-using-l293d-sn754410

    I have used and copied all the same components and wiring - exactly (i think..).

    But - the motor seems to be working at the same speed and is not turning slower or faster, as i turn the potentiometer in each direction.

    i have thought of several possibilities, for what is going wrong:

    1. maybe the guy in the Fritzing site, refers to a stepper motor and not to a regular DC motor and that changes the whole picture, since i am using a regular small DC motor?

    2. At the beginning of wiring and connecting the whole circuit together, i made a mistake and at the channels that are supposed to get 5V (red wires), i connected about 11V instead (the power that i need at max for the motor), maybe i have damaged the chip this way?


    That's it...i can't think of anything else...

    Can anyone with some serious experience, help me understanding, step by step, what is going wrong here?


    Thanks a lot!
     
    Last edited: Dec 26, 2013
  2. shteii01

    AAC Fanatic!

    Feb 19, 2010
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  3. roineust

    Thread Starter New Member

    Jul 2, 2013
    3
    0
    Sorry!
    How about now?
     
  4. nerdegutta

    Moderator

    Dec 15, 2009
    2,519
    786
    Hi.

    If you have any code. You should use the code -tags (The # in the editor menu) and copy/paste it.

    To check if the chip is damage from the 11v, you could try to disconnect all, connect a LED and try to make it flash.
     
  5. poopscoop

    Member

    Dec 12, 2012
    139
    16
    1. Yes, a stepper motor is an entirely different game. However, your set up can and will work.

    Use analogRead and map to define a variable between 0 and 254.

    Use analogWrite(Variable)

    Done.

    2. If you connected 11v to the Vin pin on the arduino then yes, you likely fried it. If you connected it anywhere before the regulator then you are fine. You can check by hitting the reset button. If the on board LED flashes a few times then you are probably (but not definitely) okay.
     
  6. roineust

    Thread Starter New Member

    Jul 2, 2013
    3
    0
    Hey people!
    Thanks!
    Your were right! I have fried the Ardu! Just as soon as i replaced it, everything started working well!

    But yet, i have another small problem - when i turn the dial in such a way, that the motor goes very slow, if at that state, i shut the whole system off (while the motor is going very slow), using a toggle switch i have there, then, even if i turn the dial back to faster motor speed - it doesn't help, and the motor won't move and only does these strange voices, as if it is trying the prime (it is hooked to a micropump) - the only thing that fixes this situation, is if i switch the wires going to the motor (+ and -) and thus switch polarity, and then the motor starts running again and then i can switch back to the right polarity and it works again!

    Does anyone know what is the source of this problem? It can't be a priming problem, since it happens even if i turn the dial to high speed before turning the system back on and this situation does not solve until i switch polarity back and forth once.

    I though, that maybe i can make the polarity switching process faster, by somehow hooking the motor + and -, after the place where the on\off toggle is located, using another toggle, the 6 legged type...is it possible to switch the DC motor polarity using one of these 6 legged type toggles ?? :

    http://static3.tme.eu/katalog_pics/b/2/3/b23356a2bb2f77e81fb2c52eb0688a8d/ms500if.jpg


    Thanks a lot, appreciate you help!
     
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