pot value

  val = analogRead(potPin); // read the value from the pot
  if(abs(val - lastVal) > 5)
  {
    Serial.println("<");
    Serial.println(val); 
    Serial.println(">");
  }

Would be nice to reset lastVal at some point, don't you think?

      var=Serial.read(); //read the character

What did you read?

      if(var=='<') //not sure what to put in if statement to run until end

How does this comment relate to this statement?