IO: Reorganize OOP examples

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

@@ -0,0 +1,25 @@
+import processing.io.*;
+SPI spi;
+
+// MCP3001 is a Analog-to-Digital converter using 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]);
+  spi.settings(500000, SPI.MSBFIRST, SPI.MODE0);
+}
+
+void draw() {
+  // dummy write, actual values don't matter
+  byte[] out = { 0, 0 };
+  byte[] in = spi.transfer(out);
+  // some input bit shifting according to the datasheet p. 16
+  int val = ((in[0] & 0x1f) << 5) | ((in[1] & 0xf8) >> 3);
+  // val is between 0 and 1023
+  background(map(val, 0, 1023, 0, 255));
+}