Arduino and DC Motor control board

Question

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

Answer 1

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

• aaa: (Welcome on Arduino.StackExchange) The problem seems to be on the potentiometer. But you're right. (When you can, you should place such an enhancement as a comment, not an answer. But you'll need some more "points".)
• RSM: Maybe add some more info to make it a non-link only answer, possibly a schematic?

Answer 2

Functionally you can replace the potmeter with a digital potmeter.
If your arduino runs on 5 volt, you can simply connect the grounds and the wire connected to the middle of the pot to a pwm pin. If the pwm pin does not work smoothly use a RC filter. That is a resis tor and a capacitor. As explained here instructables
If your arduino runs on 3.3 you can still use the rc filter but you need to add a bridge.