SPI library to the new format and moved Robot_Motor and Robot_Control libraries

libraries/Robot_Control/examples/learn/SpeedByPotentiometer/SpeedByPotentiometer.ino

@@ -0,0 +1,39 @@
+/*
+ Speed by Potentiometer
+ 
+ Control the robot's speed using the on-board
+ potentiometer. The speed will be printed on
+ the TFT screen. 
+ 
+ Circuit:
+ * Arduino Robot
+ 
+ created 1 May 2013
+ by X. Yang
+ modified 12 May 2013
+ by D. Cuartielles
+ 
+ This example is in the public domain
+ */
+
+#include <ArduinoRobot.h>
+
+void setup() {
+  // initialize the robot
+  Robot.begin();
+
+  // initialize the screen
+  Robot.beginTFT();
+}
+
+void loop() {
+  // read the value of the potentiometer
+  int val=map(Robot.knobRead(), 0, 1023, -255, 255);
+
+  // print the value to the TFT screen
+  Robot.debugPrint(val);
+
+  // set the same speed on both of the robot's wheels
+  Robot.motorsWrite(val,val);
+  delay(10);
+}