I/O: Add examples

java/libraries/io/examples/SimpleInput/SimpleInput.pde

@@ -0,0 +1,22 @@
+import processing.io.*;
+
+// RPI.PIN3 refers to the physical pin 3 on the Raspberry Pi's
+// pin header, which is located on the second row, next to the
+// 5v power pin
+
+void setup() {
+  GPIO.pinMode(RPI.PIN3, GPIO.INPUT);
+  // this is equivalent to addressing the pin with its GPIO number:
+  // GPIO.pinMode(2, GPIO.INPUT);
+}
+
+void draw() {
+  // sense the input pin
+  if (GPIO.digitalRead(RPI.PIN3) == GPIO.HIGH) {
+    fill(255);
+  } else {
+    fill(204);
+  }
+  stroke(255);
+  ellipse(width/2, height/2, width*0.75, height*0.75);
+}