IO: Reorganize OOP examples

java/libraries/io/examples/SimpleI2C/SimpleI2C.pde

@@ -0,0 +1,30 @@
+import processing.io.*;
+I2C i2c;
+
+// MCP4725 is a Digital-to-Analog converter using I2C
+// datasheet: http://ww1.microchip.com/downloads/en/DeviceDoc/22039d.pdf
+
+// also see DigitalAnalog_I2C_MCP4725 for how to write the
+// same sketch in an object-oriented way
+
+void setup() {
+  //printArray(I2C.list());
+  i2c = new I2C(I2C.list()[0]);
+}
+
+void draw() {
+  background(map(mouseX, 0, width, 0, 255));
+  setAnalog(map(mouseX, 0, width, 0.0, 1.0));
+}
+
+// outputs voltages from 0V to the supply voltage
+// (works with 3.3V and 5V)
+void setAnalog(float fac) {
+  fac = constrain(fac, 0.0, 1.0);
+  // convert to 12 bit value
+  int val = int(4095 * fac);
+  i2c.beginTransmission(0x60);
+  i2c.write(val >> 8);
+  i2c.write(val & 255);
+  i2c.endTransmission();
+}