Controlling 50 stepper motors with arduino uno

Discussion in 'The Projects Forum' started by randenius, Jul 7, 2015.

  1. randenius

    Thread Starter New Member

    Jan 4, 2015
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    My project involves controlling 50 small stepper motors with an arduino uno to move small strips of acrylics (20x500x2mm) that act as shutters.

    The stepper motor that I have is bipolar and requires 4 wires (unfortunate there is no datasheet). Hence I would need 200 inputs that would come from 25 * 74HC595. The plan is to daisy chain 25 of them, and then connect them to my L293D that I will be connecting to every motor. These will be powered by an 12V external power supply.

    My question is if there would be any issues with regard to this setup. Would appreciate any help, thanks.
     
  2. GopherT

    AAC Fanatic!

    Nov 23, 2012
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    First, is there any way to mechanically connect the strips so you can do this with ONE motor - like louvers on a sutter?

    If not, I assume they you want all motors to step the same direction and turn at the same Rae at the same time.

    If so, you could use ONE L294D and use the outputs of L294d to drive MOSFET transistors that can pass enough current to power your motors. This would greatly simplify your design.
     
  3. Alec_t

    AAC Fanatic!

    Sep 17, 2013
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    With all that inductance knocking about you will have to be careful about spike suppression and supply decoupling.
     
  4. randenius

    Thread Starter New Member

    Jan 4, 2015
    11
    0
    Do you mean L293D? I tried searching for L294D but I found nothing.

    Anyway, to make it clearer, the picture below is roughly what I'm working on. Those strips will move inwards. Not all the strips will be moving the same distance (some may not even be moving). I don't see how using one L293D to drive transistors would be able to control every motor uniquely.

    demo.png

    I'm not sure what those are.
    Spike suppression: Are you referring to the spikes generated by the back emf from inductive load? If so, would the diodes in the L293D suffice?
    Supply decoupling: I did a bit of googling on this. When the IC switches and causes a change in current drawn, the voltage changes too, hence the need for decoupling capacitors. Is this right? Would that mean I need a capacitor next to every ICs?
     
  5. Alec_t

    AAC Fanatic!

    Sep 17, 2013
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    Probably.
    Yes.
     
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