user24234: I am new in the Arduino area.
What is necessary to control motors through Arduinos. 

What is the difference between A4988 and the Arduino motor shield? 
Is one A4988 needed for each stepper motor? 
Or is one A4988 enough for all motors? 


user10394: An A4988 can control a single motor and supply up to 35V at 1.5A.
An Arduino motor shield can drive 2 DC Motors or 1 stepper motor at up to 12V and 4A/2A.
An A4988 needs mounting.
A motor shield drops straight in.
There are other options, including getting the ICs and doing it your self.  I have a motor shield which drives 4 DC motors or 2 Stepper motors that I got off eBay.

user4143: The A4988 is a bipolar stepper driver. It is designed specifically to drive a single bipolar (4-wire) stepper motor. It consists of a pair of H-bridges and some extra drive logic to provide a simple GPIO interface.
The motor shield, in contrast, uses the L298D motor driver chip. This provides, as well, two H-bridges like the A4988. However it just gives you direct control of those H-bridges without a simple stepper-oriented interface.  So it is up to you to provide the correct control signals to effectively emulate the A4988's outputs.
Both chips can interface with exactly one bipolar stepper motor. The A4988 can only interface with a stepper motor. The L298D can also be used with other types of motor (though of course not at the same time as a bipolar stepper).

24234: <p>I am new in the Arduino area.<br>
What is necessary to control motors through Arduinos. </p>

<ol>
<li>What is the difference between <a href="http://www.allegromicro.com/en/Products/Motor-Driver-And-Interface-ICs/Bipolar-Stepper-Motor-Drivers/A4988.aspx" rel="nofollow noreferrer">A4988</a> and the Arduino motor shield? </li>
<li>Is one A4988 needed for each stepper motor? </li>
<li>Or is one A4988 enough for all motors? </li>
</ol>
 10394: <p>An A4988 can control a single motor and supply up to 35V at 1.5A.
An Arduino motor shield can drive 2 DC Motors or 1 stepper motor at up to 12V and 4A/2A.</p>

<p>An A4988 needs mounting.
A motor shield drops straight in.</p>

<p>There are other options, including getting the ICs and doing it your self.  I have a motor shield which drives 4 DC motors or 2 Stepper motors that I got off eBay.</p>
 4143: <p>The A4988 is a bipolar stepper driver. It is designed specifically to drive a single bipolar (4-wire) stepper motor. It consists of a pair of H-bridges and some extra drive logic to provide a simple GPIO interface.</p>

<p>The motor shield, in contrast, uses the L298D motor driver chip. This provides, as well, two H-bridges like the A4988. However it just gives you direct control of those H-bridges without a simple stepper-oriented interface.  So it is up to you to provide the correct control signals to effectively emulate the A4988's outputs.</p>

<p>Both chips can interface with exactly one bipolar stepper motor. The A4988 can <em>only</em> interface with a stepper motor. The L298D can <em>also</em> be used with other types of motor (though of course not at the same time as a bipolar stepper).</p>
