Synaptics SDK can't find device

Question

I'm attempting to grab a device handle on the Synaptics Touchpad using the Synaptics SDK, specifically using methods in the SYNCTRLLib. However, the SYNCTRL method failed to find it, returning -1.

Syn.cs:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using SYNCOMLib;
using SYNCTRLLib;

namespace TP_Test1
{
    class Syn
    {
        SynAPICtrl SynTP_API = new SynAPICtrl();
        SynDeviceCtrl SynTP_Dev = new SynDeviceCtrl();
        SynPacketCtrl SynTP_Pack = new SynPacketCtrl();
        int DeviceHandle;

        //Constructor
        public Syn ()
        {
            SynTP_API.Initialize();
            SynTP_API.Activate();

            //DeviceHandle == -1 ? Can't find device?
            DeviceHandle = SynTP_API.FindDevice(new SynConnectionType(), new SynDeviceType(), 0);
            //Below line causing Unhandled Exception
            SynTP_Dev.Select(DeviceHandle);
            SynTP_Dev.Activate();
            SynTP_Dev.OnPacket += SynTP_Dev_OnPacket;
        }

        public void SynTP_Dev_OnPacket()
        {
                Console.WriteLine(SynTP_Pack.FingerState);
                Console.WriteLine(SynTP_Pack.X);
                Console.WriteLine(SynTP_Pack.Y);
        }
    }
}

Program.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using SYNCOMLib;
using SYNCTRLLib;

namespace TP_Test1
{
    class Program
    {
        static void Main(string[] args)
        {
            Syn mySyn = new Syn();
            mySyn.SynTP_Dev_OnPacket();
        }
    }
}

Answer 1

I see that you are using the C# wrappers for Synaptics SDK. Even though CPP code might be not trivial to you, you might want to take a look at the file Samples/ComTest.cpp. It contains some example logic in order to find devices, more specifically at lines 66-76:

  // Find a device, preferentially a TouchPad or Styk.
  ISynDevice *pDevice = 0;
  long lHandle = -1;
  if ((pAPI->FindDevice(SE_ConnectionAny, SE_DeviceTouchPad, &lHandle) &&
       pAPI->FindDevice(SE_ConnectionAny, SE_DeviceStyk, &lHandle) &&
       pAPI->FindDevice(SE_ConnectionAny, SE_DeviceAny, &lHandle)) || 
      pAPI->CreateDevice(lHandle, &pDevice))
  {
    printf("Unable to find a Synaptics Device.\n");
    exit(-1);
  }

Also, make sure you have registered the dlls. According to the ReadSynSDK.txt file:

For certain purposes it may be necessary to register the dlls that are provided with the SDK. This can be done with the windows regsvr32 utility.