 int Direction =0;//direction 0 =CW
 int x;
 int StepValue;
-//the lines below are so that you can quickly change this code if you want to
-//use the DCU in the BTD1 connector for some reason.
-int DCUinBTD2=1;// change this to 0 if you want to use the DCU on BTD 1
-const int Pin1 = 2 +DCUinBTD2*4;
-const int Pin2 = 3 +DCUinBTD2*4;
-const int Pin3 = 4 +DCUinBTD2*4;
-const int Pin4 = 5 +DCUinBTD2*4;
+const int Pin1 = 6;
+const int Pin2 = 7;
+const int Pin3 = 8;
+const int Pin4 = 9;
 int photogate =2; //This is the input for a photogate on the BTD 1 connector
 int LEDpin =13;/// line for LED to turn on when photogate is blocked
 int output; //number sent to DCU

    } ;//end of for
};// end of Step
 
void DCU (int output)
{
  switch (output) 
  {


A Vernier Photogate should also be connnected to the second BTD 1 connector.
The sketch monitors this photogate and Controls a stepper motor (unipolar or 
bipolar) via a Vernier Digital Control Unit (DCU) connected to the BTD 2 
connector.

This sketch will continuously check the photogate and start the stepper
