IO: Reorganize OOP examples

java/libraries/io/examples/Compass_I2C_HMC6352/Compass_I2C_HMC6352.pde

@@ -0,0 +1,19 @@
+import processing.io.*;
+HMC6352 compass;
+
+// see setup.png in the sketch folder for wiring details
+
+void setup() {
+  // the module's I2C address can be changed by modifying values in its EEPROM
+  // 0x21 is however the default address
+
+  //printArray(I2C.list());
+  compass = new HMC6352("i2c-1", 0x21);
+}
+
+void draw() {
+  background(255);
+  float deg = compass.heading();
+  println(deg + " degrees");
+  line(width/2, height/2, width/2+sin(radians(deg))*width/2, height/2-cos(radians(deg))*height/2);
+}

java/libraries/io/examples/Compass_I2C_HMC6352/HMC6352.pde

@@ -0,0 +1,38 @@
+import processing.io.I2C;
+
+// HMC6352 is a digital compass using I2C
+// datasheet: https://www.sparkfun.com/datasheets/Components/HMC6352.pdf
+
+class HMC6352 extends I2C {
+  int address;
+
+  HMC6352(String dev, int address) {
+    super(dev);
+    this.address = address;
+    setHeadingMode();
+  }
+
+  void setHeadingMode() {
+    beginTransmission(address);
+    // command byte for writing to EEPROM
+    write(0x77);
+    // address of the output data control byte
+    write(0x4e);
+    // give us the plain heading
+    write(0x00);
+    endTransmission();
+  }
+
+  float heading() {
+    beginTransmission(address);
+    // command byte for reading the data
+    write(0x41);
+    byte[] in = read(2);
+    endTransmission();
+    // put bytes together to tenth of degrees
+    // & 0xff makes sure the byte is not interpreted as a negative value
+    int deg = (in[0] & 0xff) << 8 | (in[1] & 0xff);
+    // return degrees
+    return deg / 10.0;
+  }
+}

java/libraries/io/examples/I2CCompass/I2CCompass.pde

@@ -1,43 +0,0 @@
-import processing.io.*;
-I2C i2c;
-
-// HMC6352 is a digital compass module using I2C
-// datasheet: https://www.sparkfun.com/datasheets/Components/HMC6352.pdf
-// see setup.png in the sketch folder for wiring details
-
-void setup() {
-  //printArray(I2C.list());
-  i2c = new I2C(I2C.list()[0]);
-  setHeadingMode();
-}
-
-void draw() {
-  background(255);
-  float deg = getHeading();
-  println(deg + " degrees");
-  line(width/2, height/2, width/2+sin(radians(deg))*width/2, height/2-cos(radians(deg))*height/2);
-}
-
-void setHeadingMode() {
-  i2c.beginTransmission(0x21);
-  // command byte for writing to EEPROM
-  i2c.write(0x77);
-  // address of the output data control byte
-  i2c.write(0x4e);
-  // give us the plain heading
-  i2c.write(0x00);
-  i2c.endTransmission();
-}
-
-float getHeading() {
-  i2c.beginTransmission(0x21);
-  // command byte for reading the data
-  i2c.write(0x41);
-  byte[] in = i2c.read(2);
-  i2c.endTransmission();
-  // put bytes together to tenth of degrees
-  // & 0xff makes sure the byte is not interpreted as a negative value
-  int deg = (in[0] & 0xff) << 8 | (in[1] & 0xff);
-  // return degrees
-  return deg / 10.0;
-}

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

@@ -4,6 +4,9 @@ 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]);

java/libraries/io/examples/SimpleSPI/SimpleSPI.pde

@@ -5,6 +5,9 @@ SPI spi;
 // datasheet: http://ww1.microchip.com/downloads/en/DeviceDoc/21293C.pdf
 // see setup.png in the sketch folder for wiring details
 
+// also see AnalogDigital_SPI_MCP3001 for how to write the
+// same sketch in an object-oriented way
+
 void setup() {
   //printArray(SPI.list());
   spi = new SPI(SPI.list()[0]);