title: Importing DLL into Unity - Type or namespace could not be found
body: <p>I'm working on a project using a USB interface device (see <a href="http://www.velleman.eu/support/downloads/?code=K8055" rel="nofollow">here</a>), and trying to use the DLL provided in the SDK pack within my Unity application. The end goal is to allow Unity to access inputs and outputs from the hardware - functionality for this is provided by the DLL.</p>
  
  <p><a href="http://imgur.com/i7v4gmH" rel="nofollow">I added the DLL to the project</a>, and tried to access it from a script.</p>
  
  <pre><code>using UnityEngine;
  using System.Collections;
  using k8055d;
  
  public class DLLTest01 : MonoBehaviour 
  {   
      public k8055d usbHandler;
  
      void Start(){}
  }
  </code></pre>
  
  <p>Unity threw me an error. The error was:</p>
  
  <blockquote>
    <p>Assets/Resources/Scripts/DLLTest01.cs(3,7): error CS0246: The type or
    namespace name `k8055d' could not be found. Are you missing a using
    directive or an assembly reference?</p>
  </blockquote>
  
  <p>The DLL is definitely within the project's folder, and named 'k8055d.dll', what could be the cause of this and what can I do to get the DLL working with any games I happen to make for my hardware device?</p>
  
  <p>I feel like this may have something to do with the .NET version that Unity is using but I'm not sure what I can do if that's the issue.</p>