examples: add Firmata blink metal example

Signed-off-by: deadprogram <[email protected]>

examples/firmata_blink_metal.go

@@ -0,0 +1,25 @@
+package main
+
+import (
+	"time"
+
+	"github.com/hybridgroup/gobot/drivers/gpio"
+	"github.com/hybridgroup/gobot/platforms/firmata"
+)
+
+// Example of a simple led toggle without the initialization of
+// the entire gobot framework.
+// This might be useful if you want to use gobot as another
+// golang library to interact with sensors and other devices.
+func main() {
+	f := firmata.NewAdaptor("/dev/ttyACM0")
+	f.Connect()
+
+	led := gpio.NewLedDriver(f, "13")
+	led.Start()
+
+	for {
+		led.Toggle()
+		time.Sleep(1000 * time.Millisecond)
+	}
+}