Add support for blinking usr leds

examples/beaglebone_blink_usr_led.go

@@ -0,0 +1,32 @@
+package main
+
+import (
+	"time"
+
+	"github.com/hybridgroup/gobot"
+	"github.com/hybridgroup/gobot/platforms/beaglebone"
+	"github.com/hybridgroup/gobot/platforms/gpio"
+)
+
+func main() {
+	gbot := gobot.NewGobot()
+
+	beagleboneAdaptor := beaglebone.NewBeagleboneAdaptor("beaglebone")
+	led := gpio.NewLedDriver(beagleboneAdaptor, "led", "usr0")
+
+	work := func() {
+		gobot.Every(1*time.Second, func() {
+			led.Toggle()
+		})
+	}
+
+	robot := gobot.NewRobot("blinkBot",
+		[]gobot.Connection{beagleboneAdaptor},
+		[]gobot.Device{led},
+		work,
+	)
+
+	gbot.AddRobot(robot)
+
+	gbot.Start()
+}

platforms/beaglebone/beaglebone_adaptor.go

@@ -4,6 +4,7 @@ import (
 	"bufio"
 	"fmt"
 	"github.com/hybridgroup/gobot"
+	"log"
 	"os"
 	"path/filepath"
 	"strconv"
@@ -13,7 +14,8 @@ import (
 const (
 	Slots       = "/sys/devices/bone_capemgr.*"
 	Ocp         = "/sys/devices/ocp.*"
- 	I2CLocation = "/dev/i2c-1"
+	I2CLocation = "/dev/i2c-1"
+	UsrLed      = "/sys/devices/ocp.3/gpio-leds.8/leds/beaglebone:green:"
 )
 
 var pins = map[string]int{
@@ -171,8 +173,17 @@ func (b *BeagleboneAdaptor) DigitalRead(pin string) int {
 }
 
 func (b *BeagleboneAdaptor) DigitalWrite(pin string, val byte) {
-	i := b.digitalPin(pin, "w")
-	b.digitalPins[i].digitalWrite(strconv.Itoa(int(val)))
+	if strings.Contains(pin, "usr") {
+		fi, err := os.OpenFile(UsrLed+pin+"/brightness", os.O_WRONLY|os.O_APPEND, 0666)
+		if err != nil {
+			log.Fatal(err)
+		}
+		defer fi.Close()
+		fi.WriteString(strconv.Itoa(int(val)))
+	} else {
+		i := b.digitalPin(pin, "w")
+		b.digitalPins[i].digitalWrite(strconv.Itoa(int(val)))
+	}
 }
 
 func (b *BeagleboneAdaptor) AnalogRead(pin string) int {