Example for direct GPIO control on Beaglebone

* Contains some annotated on potential gotchas
* Penance for hybridgroup#98

examples/beaglebone_basic_direct_pin.go

@@ -0,0 +1,25 @@
+// Use Gobot to control BeagleBone's digital pins directly
+package main
+
+import (
+	"github.com/hybridgroup/gobot/platforms/beaglebone"
+	"github.com/hybridgroup/gobot/platforms/gpio"
+)
+
+func main() {
+
+	beagleboneAdaptor := beaglebone.NewBeagleboneAdaptor("beaglebone")
+	gpioPin           := gpio.NewDirectPinDriver(beagleboneAdaptor, "myDevice", "P9_12")
+
+	// Initialize the internal representation of the pinout
+	beagleboneAdaptor.Connect()
+
+	// Cast to byte because we are returning an int from a function
+	// and not passing in an int literal.
+	gpioPin.DigitalWrite(byte(myStateFunction()))
+}
+
+// myStateFunction determines what the GPIO state should be
+func myStateFunction() int {
+	return 1
+}