user19325: I've this PWM Module - 6V-90V 15A Pulse Width PWM DC Motor Speed Controller Switch which I use to control a peristaltic pump (ordinary DC motor), now I want to replace the potentiometer with an Arduino in order to create a soft-start for the pump by pressing a button. 
The control is a 0-5V input from the potentiometer, and the description says "you can external drive" and "It could use of PLC controls speed of motor", unfortunately I cannot provide datasheets or schematics.  
Is it possible? Or I need a digital pot?    
How should I wire it? The 3 cables from the board to the pot are: ground, 0-5V and 5V

user19322: Or you may exchange the whole controller with a power mosfet module connected to your arduino. And use pwm directly from your arduino.
http://store.arduino.cc/product/T010020

19325: <p>I've this <a href="http://m.aliexpress.com/item/32584436489.html" rel="nofollow">PWM Module - 6V-90V 15A Pulse Width PWM DC Motor Speed Controller Switch</a> which I use to control a peristaltic pump (ordinary DC motor), now I want to replace the potentiometer with an Arduino in order to create a soft-start for the pump by pressing a button. 
The control is a 0-5V input from the potentiometer, and the description says "<em>you can external drive</em>" and "<em>It could use of PLC controls speed of motor</em>", unfortunately I cannot provide datasheets or schematics.  </p>

<p>Is it possible? Or I need a digital pot?    </p>

<p>How should I wire it? The 3 cables from the board to the pot are: <strong>ground, 0-5V and 5V</strong></p>
 19322: <p>Or you may exchange the whole controller with a power mosfet module connected to your arduino. And use pwm directly from your arduino.
<a href="http://store.arduino.cc/product/T010020" rel="nofollow">http://store.arduino.cc/product/T010020</a></p>
