diff --git a/P4wnP1_client_cli/cli_client.go b/P4wnP1_client_cli/cli_client.go
index b12d93b..9f2258b 100644
--- a/P4wnP1_client_cli/cli_client.go
+++ b/P4wnP1_client_cli/cli_client.go
@@ -3,19 +3,27 @@ package main
 import (
 	"log"
 	"time"
-	"reflect"
+//	"reflect"
+	"flag" //will be replaced with cobra 
 
 	"golang.org/x/net/context"
 	"google.golang.org/grpc"
 	pb "../proto"
 )
 
-const (
-	address     = "localhost:50051"
-)
-
 func main() {
+	//Parse cli flags, should be replaced with cobra
+	blinkCountPtr := flag.Int("blink", -1, "LED blink count (0 = LED off, 255 = LED solid, 1..254 blink n times)")
+	var rpcHostPtr string
+	var rpcPortPtr string
+	flag.StringVar(&rpcHostPtr, "host", "localhost", "The remote RPC host running P4wnP1 service")
+	flag.StringVar(&rpcPortPtr, "port", "50051", "The remote RPC port of P4wnP1 service")
+	flag.Parse()
+	
+	
 	// Set up a connection to the server.
+	address := rpcHostPtr + ":" + rpcPortPtr
+	log.Printf("Connecting %s ...", address)
 	conn, err := grpc.Dial(address, grpc.WithInsecure())
 	if err != nil {
 		log.Fatalf("did not connect: %v", err)
@@ -23,12 +31,23 @@ func main() {
 	defer conn.Close()
 	c := pb.NewP4WNP1Client(conn)
 
-	// Contact the server and print out its response.
+	// Contact the server
 	ctx, cancel := context.WithTimeout(context.Background(), time.Second)
 	defer cancel()
+
+	if *blinkCountPtr >= 0 {
+		c.SetLEDSettings(ctx, &pb.LEDSettings{ BlinkCount: uint32(*blinkCountPtr) })
+	}
+
+	
+	/*
 	r, err := c.GetGadgetSettings(ctx, &pb.Empty{})
 	if err != nil {
 		log.Fatalf("could not get GadgetSettings: %v", err)
 	}
 	log.Printf("USB Settings %s: %+v", reflect.TypeOf(*r), *r)
+	
+	log.Printf("Set LED to blink count 3")
+	c.SetLEDSettings(ctx, &pb.LEDSettings{ BlinkCount: 3})
+	*/
 }
diff --git a/core/led.go b/core/led.go
index c22430e..006cfab 100644
--- a/core/led.go
+++ b/core/led.go
@@ -1,11 +1,11 @@
-//package led
-package main
+package core
 
 import(
 	"os"
 	"log"
 	"io/ioutil"
 	"time"
+	"sync/atomic"
 
 	pb "../proto"
 )
@@ -21,7 +21,11 @@ const (
 	LED_DELAY_PAUSE = 500 * time.Millisecond
 )
 
-func initLed(led_on bool) (error) {
+var (
+	blink_count uint32 = 0
+)
+
+func InitLed(led_on bool) (error) {
 	//set trigger of LED to manual
 	log.Println("Setting LED to manual trigger ...")
 	ioutil.WriteFile(LED_TRIGGER_PATH, []byte(LED_TRIGGER_MANUAL), os.ModePerm)
@@ -32,35 +36,34 @@ func initLed(led_on bool) (error) {
 		log.Println("Setting LED to OFF ...")
 		ioutil.WriteFile(LED_BRIGHTNESS_PATH, []byte(LED_OFF), os.ModePerm)
 	}
+	atomic.StoreUint32(&blink_count, 0)
+	
+	go led_loop()
+	
 	return nil
 }
 
 func led_loop() {
-	blink_count := 10
+	
 	for {
-		for i := 0; i <= blink_count; i++ {
+		for i := uint32(0); i < atomic.LoadUint32(&blink_count); i++ {
 			ioutil.WriteFile(LED_BRIGHTNESS_PATH, []byte(LED_ON), os.ModePerm)
 			time.Sleep(LED_DELAY_ON)
-			ioutil.WriteFile(LED_BRIGHTNESS_PATH, []byte(LED_OFF), os.ModePerm)
-			time.Sleep(LED_DELAY_OFF)
+			
+			//Don't turn off led if blink_count >= 255 (solid)
+			if 255 > atomic.LoadUint32(&blink_count) {
+				ioutil.WriteFile(LED_BRIGHTNESS_PATH, []byte(LED_OFF), os.ModePerm)
+				time.Sleep(LED_DELAY_OFF)
+			}
 		}
 		time.Sleep(LED_DELAY_PAUSE)
 	}
 }
 
 func setLed(s pb.LEDSettings) (error) {
+	log.Printf("setLED called with %+v", s)
 	
+	atomic.StoreUint32(&blink_count, s.BlinkCount)
 	
 	return nil
 }
-
-func main() {
-	initLed(false)
-	
-	log.Println("testing led")
-	settings := pb.LEDSettings{}
-	setLed(settings)
-	
-	go led_loop()
-	time.Sleep(10 * time.Second)
-}
diff --git a/P4wnP1_service/service.go b/core/rpcsrv.go
similarity index 64%
rename from P4wnP1_service/service.go
rename to core/rpcsrv.go
index 91f0923..caf2897 100644
--- a/P4wnP1_service/service.go
+++ b/core/rpcsrv.go
@@ -1,41 +1,41 @@
-package main
+//package rpcserv
+package core
 
 import (
+	"encoding/json"
 	"log"
 	"net"
-	"encoding/json"
 
+	pb "../proto"
 	"golang.org/x/net/context"
 	"google.golang.org/grpc"
-	pb "../proto"
 	"google.golang.org/grpc/reflection"
 )
 
-
 type server struct{}
 
 //Attach handler function implementing the "GetGadgetSettings" interface to server
 func (s *server) GetGadgetSettings(context.Context, *pb.Empty) (*pb.GadgetSettings, error) {
-	usbset := &pb.GadgetSettings {
-		Pid: "0x1337",
-		Vid: "0x1222",
-		Manufacturer: "MaMe82",
-		Serial: "deadbeef13371337",
-		Product: "P4wnP1 by MaMe82",
-		Use_RNDIS: false,
-		Use_CDC_ECM: true,
+	usbset := &pb.GadgetSettings{
+		Pid:              "0x1337",
+		Vid:              "0x1222",
+		Manufacturer:     "MaMe82",
+		Serial:           "deadbeef13371337",
+		Product:          "P4wnP1 by MaMe82",
+		Use_RNDIS:        false,
+		Use_CDC_ECM:      true,
 		Use_HID_KEYBOARD: false,
-		Use_HID_MOUSE: false,
-		Use_HID_RAW: false,
-		Use_UMS: false,
-		Use_SERIAL: false,
-		
-		RndisSettings: &pb.GadgetSettingsEthernet { HostAddr: "11:22:33:44:55:66", DevAddr: "66:55:44:33:22:11", },
-		CdcEcmSettings: &pb.GadgetSettingsEthernet { HostAddr: "11:22:33:54:76:98", DevAddr: "66:55:44:98:76:54", },
+		Use_HID_MOUSE:    false,
+		Use_HID_RAW:      false,
+		Use_UMS:          false,
+		Use_SERIAL:       false,
+
+		RndisSettings:  &pb.GadgetSettingsEthernet{HostAddr: "11:22:33:44:55:66", DevAddr: "66:55:44:33:22:11"},
+		CdcEcmSettings: &pb.GadgetSettingsEthernet{HostAddr: "11:22:33:54:76:98", DevAddr: "66:55:44:98:76:54"},
 	}
 	j_usbset, _ := json.Marshal(usbset)
 	log.Printf("Gadget settings requested %v", string(j_usbset))
-	
+
 	return usbset, nil
 }
 
@@ -59,29 +59,27 @@ func (s *server) GetLEDSettings(context.Context, *pb.Empty) (*pb.LEDSettings, er
 	return led_settings, nil
 }
 
-func (s *server) SetLEDSettings(context.Context, *pb.LEDSettings) (*pb.Error, error) {
+func (s *server) SetLEDSettings(ctx context.Context, ledSettings *pb.LEDSettings) (rpcerr *pb.Error, err error) {
+	log.Printf("SetLEDSettings %+v", ledSettings)
+	setLed(*ledSettings)
 	return &pb.Error{Err: 0}, nil
 }
 
-func start_rpc_server(host string, port string) {
-	listen_address := host+":"+port
+func StartRpcServer(host string, port string) {
+	listen_address := host + ":" + port
 	//Open TCP listener
 	log.Printf("P4wnP1 RPC server lsitening on " + listen_address)
 	lis, err := net.Listen("tcp", listen_address)
 	if err != nil {
 		log.Fatalf("failed to listen: %v", err)
 	}
-	
+
 	//Create gRPC Server
 	s := grpc.NewServer()
 	pb.RegisterP4WNP1Server(s, &server{})
 	// Register reflection service on gRPC server.
 	reflection.Register(s)
 	if err := s.Serve(lis); err != nil {
-		log.Fatalf("failed to serve: %v", err)
+		log.Fatalf("Failed to serve: %v", err)
 	}
 }
-
-func main() {
-	start_rpc_server("127.0.0.1", "50051")
-}
diff --git a/core/usb.go b/core/usb.go
index e1879aa..c540e43 100644
--- a/core/usb.go
+++ b/core/usb.go
@@ -1,210 +1,160 @@
-package usb
+package core
 
-import(
+import (
 	"errors"
-	"os"
-	"fmt"
 	"io/ioutil"
+	"log"
+	"os"
+	"os/exec"
+	"strings"
+
+	pb "../proto"
 )
 
 const (
-	USB_GADGET_DIR_BASE = "/sys/kernel/config/usb_gadget"
-	USB_GADGET_DIR = USB_GADGET_DIR_BASE + "/mame82_gadget"
-	USB_DEFAULT_SERIAL = "deadbeefdeadbeef"
+	USB_GADGET_DIR_BASE      = "/sys/kernel/config/usb_gadget"
+	USB_GADGET_DIR           = USB_GADGET_DIR_BASE + "/mame82_gadget"
+	USB_DEFAULT_SERIAL       = "deadbeefdeadbeef"
 	USB_DEFAULT_MANUFACTURER = "MaMe82"
-	USB_DEFAULT_PRODUCT = "P4wnP1 by MaMe82"
-	
+	USB_DEFAULT_PRODUCT      = "P4wnP1 by MaMe82"
+
 	USB_bcdDevice = "0x0100" //Version 1.00
-	USB_bcdUSB = "0x0200" //mode: USB 2.0
+	USB_bcdUSB    = "0x0200" //mode: USB 2.0
 
 	// composite class / subclass / proto (needs single configuration)
-	USB_bDeviceClass = "0xEF"
+	USB_bDeviceClass    = "0xEF"
 	USB_bDeviceSubClass = "0x02"
 	USB_bDeviceProtocol = "0x01"
-	
-	USB_CONFIGURATION_MaxPower = "250"
+
+	USB_CONFIGURATION_MaxPower     = "250"
 	USB_CONFIGURATION_bmAttributes = "0x80" //should be 0x03 for USB_OTG_SRP | USB_OTG_HNP
 
-	//RNDIS function constants
-	USB_FUNCTION_RNDIS_DEFAULT_host_addr = "42:63:65:12:34:56"
-	USB_FUNCTION_RNDIS_DEFAULT_dev_addr = "42:63:65:56:34:12"
+	/*
+		//RNDIS function constants
+		USB_FUNCTION_RNDIS_DEFAULT_host_addr = "42:63:65:12:34:56"
+		USB_FUNCTION_RNDIS_DEFAULT_dev_addr  = "42:63:65:56:34:12"
+	*/
 	//OS descriptors for RNDIS composite function on Windows
-	USB_FUNCTION_RNDIS_os_desc_use = "1"
-	USB_FUNCTION_RNDIS_os_desc_b_vendor_code = "0xbc"
-	USB_FUNCTION_RNDIS_os_desc_qw_sign = "MSFT100"
-	USB_FUNCTION_RNDIS_os_desc_interface_compatible_id = "RNDIS"
+	USB_FUNCTION_RNDIS_os_desc_use                         = "1"
+	USB_FUNCTION_RNDIS_os_desc_b_vendor_code               = "0xbc"
+	USB_FUNCTION_RNDIS_os_desc_qw_sign                     = "MSFT100"
+	USB_FUNCTION_RNDIS_os_desc_interface_compatible_id     = "RNDIS"
 	USB_FUNCTION_RNDIS_os_desc_interface_sub_compatible_id = "5162001"
-	
-	//CDC ECM function constants
-	USB_FUNCTION_CDC_ECM_DEFAULT_host_addr = "42:63:66:12:34:56"
-	USB_FUNCTION_CDC_ECM_DEFAULT_dev_addr = "42:63:66:56:34:12"
-	
+
+	/*
+		//CDC ECM function constants
+		USB_FUNCTION_CDC_ECM_DEFAULT_host_addr = "42:63:66:12:34:56"
+		USB_FUNCTION_CDC_ECM_DEFAULT_dev_addr  = "42:63:66:56:34:12"
+	*/
+
 	//HID function, keyboard constants
-	USB_FUNCTION_HID_KEYBOARD_protocol = "1"
-	USB_FUNCTION_HID_KEYBOARD_subclass = "1"
+	USB_FUNCTION_HID_KEYBOARD_protocol      = "1"
+	USB_FUNCTION_HID_KEYBOARD_subclass      = "1"
 	USB_FUNCTION_HID_KEYBOARD_report_length = "8"
-	USB_FUNCTION_HID_KEYBOARD_report_desc = "\x05\x01\t\x06\xa1\x01\x05\x07\x19\xe0)\xe7\x15\x00%\x01u\x01\x95\x08\x81\x02\x95\x01u\x08\x81\x03\x95\x05u\x01\x05\x08\x19\x01)\x05\x91\x02\x95\x01u\x03\x91\x03\x95\x06u\x08\x15\x00%e\x05\x07\x19\x00)e\x81\x00\xc0"
-	USB_FUNCTION_HID_KEYBOARD_name = "hid.keyboard"
-	
+	USB_FUNCTION_HID_KEYBOARD_report_desc   = "\x05\x01\t\x06\xa1\x01\x05\x07\x19\xe0)\xe7\x15\x00%\x01u\x01\x95\x08\x81\x02\x95\x01u\x08\x81\x03\x95\x05u\x01\x05\x08\x19\x01)\x05\x91\x02\x95\x01u\x03\x91\x03\x95\x06u\x08\x15\x00%e\x05\x07\x19\x00)e\x81\x00\xc0"
+	USB_FUNCTION_HID_KEYBOARD_name          = "hid.keyboard"
+
 	//HID function, mouse constants
-	USB_FUNCTION_HID_MOUSE_protocol = "2"
-	USB_FUNCTION_HID_MOUSE_subclass = "1"
+	USB_FUNCTION_HID_MOUSE_protocol      = "2"
+	USB_FUNCTION_HID_MOUSE_subclass      = "1"
 	USB_FUNCTION_HID_MOUSE_report_length = "6"
-	USB_FUNCTION_HID_MOUSE_report_desc = "\x05\x01\t\x02\xa1\x01\t\x01\xa1\x00\x85\x01\x05\t\x19\x01)\x03\x15\x00%\x01\x95\x03u\x01\x81\x02\x95\x01u\x05\x81\x03\x05\x01\t0\t1\x15\x81%\x7fu\x08\x95\x02\x81\x06\x95\x02u\x08\x81\x01\xc0\xc0\x05\x01\t\x02\xa1\x01\t\x01\xa1\x00\x85\x02\x05\t\x19\x01)\x03\x15\x00%\x01\x95\x03u\x01\x81\x02\x95\x01u\x05\x81\x01\x05\x01\t0\t1\x15\x00&\xff\x7f\x95\x02u\x10\x81\x02\xc0\xc0"
-	USB_FUNCTION_HID_MOUSE_name = "hid.mouse"
-	
+	USB_FUNCTION_HID_MOUSE_report_desc   = "\x05\x01\t\x02\xa1\x01\t\x01\xa1\x00\x85\x01\x05\t\x19\x01)\x03\x15\x00%\x01\x95\x03u\x01\x81\x02\x95\x01u\x05\x81\x03\x05\x01\t0\t1\x15\x81%\x7fu\x08\x95\x02\x81\x06\x95\x02u\x08\x81\x01\xc0\xc0\x05\x01\t\x02\xa1\x01\t\x01\xa1\x00\x85\x02\x05\t\x19\x01)\x03\x15\x00%\x01\x95\x03u\x01\x81\x02\x95\x01u\x05\x81\x01\x05\x01\t0\t1\x15\x00&\xff\x7f\x95\x02u\x10\x81\x02\xc0\xc0"
+	USB_FUNCTION_HID_MOUSE_name          = "hid.mouse"
+
 	//HID function, custom vendor device constants
-	USB_FUNCTION_HID_RAW_protocol = "1"
-	USB_FUNCTION_HID_RAW_subclass = "1"
+	USB_FUNCTION_HID_RAW_protocol      = "1"
+	USB_FUNCTION_HID_RAW_subclass      = "1"
 	USB_FUNCTION_HID_RAW_report_length = "64"
-	USB_FUNCTION_HID_RAW_report_desc = "\x06\x00\xff\t\x01\xa1\x01\t\x01\x15\x00&\xff\x00u\x08\x95@\x81\x02\t\x02\x15\x00&\xff\x00u\x08\x95@\x91\x02\xc0"
-	USB_FUNCTION_HID_RAW_name = "hid.raw"
+	USB_FUNCTION_HID_RAW_report_desc   = "\x06\x00\xff\t\x01\xa1\x01\t\x01\x15\x00&\xff\x00u\x08\x95@\x81\x02\t\x02\x15\x00&\xff\x00u\x08\x95@\x91\x02\xc0"
+	USB_FUNCTION_HID_RAW_name          = "hid.raw"
 )
 
-type USB struct {
-	Vid string
-	Pid string
-	Manufacturer string
-	Product string
-	Serial string
-	Use_CDC_ECM bool
-	Use_RNDIS bool
-	Use_HID_KEYBOARD bool
-	Use_HID_MOUSE bool
-	Use_HID_RAW bool
-	Use_UMS bool
-	Use_SERIAL bool
+func InitDefaultGadgetSettings() error {
+	return InitGadget(CreateDefaultGadgetSettings())
 }
 
-func DestroyAllGadgets() error {
-	//gadget_root := "./test"
-	gadget_root := USB_GADGET_DIR_BASE
-	
-	//check if root exists, return error otherwise
-	if _, err := os.Stat(gadget_root); os.IsNotExist(err) {
-		return errors.New("Configfs path for gadget doesn't exist") 
+func CreateDefaultGadgetSettings() (res pb.GadgetSettings) {
+	res = pb.GadgetSettings{
+		Vid:              "0x1d6b",
+		Pid:              "0x1337",
+		Manufacturer:     "MaMe82",
+		Product:          "P4wnP1 by MaMe82",
+		Serial:           "deadbeef1337",
+		Use_CDC_ECM:      true,
+		Use_RNDIS:        true,
+		Use_HID_KEYBOARD: false,
+		Use_HID_MOUSE:    false,
+		Use_HID_RAW:      false,
+		Use_UMS:          false,
+		Use_SERIAL:       false,
+		RndisSettings: &pb.GadgetSettingsEthernet{
+			HostAddr: "42:63:65:12:34:56",
+			DevAddr:  "42:63:65:56:34:12",
+		},
+		CdcEcmSettings: &pb.GadgetSettingsEthernet{
+			HostAddr: "42:63:66:12:34:56",
+			DevAddr:  "42:63:66:56:34:12",
+		},
 	}
-	
-	gadget_dirs, err := ioutil.ReadDir(gadget_root)
+
+	return res
+}
+
+//depends on `bash`, `grep` and `lsmod` binary
+func CheckLibComposite() error {
+	log.Printf("Checking for libcomposite...")
+	out, err := exec.Command("lsmod").Output()
 	if err != nil {
-		return errors.New("No gadgets") 
+		log.Fatal(err)
 	}
-	
-	for _, gadget_dir_obj := range gadget_dirs {
-		gadget_name := gadget_dir_obj.Name()
-		fmt.Println("Found gadget: "+gadget_name)
-		err = DestroyGadget(gadget_name)
-		if err != nil {
-			fmt.Println(err) //don't return, continue with next
-		}
+
+	if strings.Contains(string(out), "libcomposite") {
+		log.Printf("... libcomposite loaded")
+		return nil
 	}
-	
-	return nil
+
+	//if here, libcomposite isn't loaded ... try to load
+	log.Printf("Libcomposite not loaded, trying to fix ...")
+	err = exec.Command("modprobe", "libcomposite").Run()
+	if err == nil {
+		log.Printf("... libcomposite loaded")
+	}
+
+	return err
 }
 
-func DestroyGadget(Gadget_name string) error {
-	//gadget_root := "./test"
-	gadget_dir := USB_GADGET_DIR_BASE + "/" + Gadget_name
-	
-	//check if root exists, return error otherwise
-	if _, err := os.Stat(USB_GADGET_DIR_BASE); os.IsNotExist(err) {
-		return errors.New("Gadget " + Gadget_name + " doesn't exist") 
-	}
-	fmt.Println("Deconstructing gadget " + Gadget_name + "...")
-	
-	//Assure gadget gets unbound from UDC
-	ioutil.WriteFile(gadget_dir+"/UDC", []byte("\x00"), os.ModePerm)
-
-	//Iterate over configurations
-	config_dirs, _ := ioutil.ReadDir(gadget_dir + "/configs")
-	for _, conf_dir_obj := range config_dirs {
-		conf_name := conf_dir_obj.Name()
-		conf_dir := gadget_dir + "/configs/" + conf_name
-		fmt.Println("Found config: " + conf_name)
-		
-		//find linked functions
-		conf_content, _ := ioutil.ReadDir(conf_dir)
-		for _, function := range conf_content {
-			//Remove link from function to config
-			if function.Mode() & os.ModeSymlink > 0 { 
-				fmt.Println("\tRemoving function " + function.Name() + " from config " + conf_name)
-				os.Remove(conf_dir + "/" + function.Name())
-			}
-		}
-		
-		//find string directories in config
-		strings_content, _ := ioutil.ReadDir(conf_dir + "/strings")
-		for _, str := range strings_content {
-			string_dir := str.Name()
-			//Remove string from config
-			fmt.Println("\tRemoving string dir '" + string_dir + "' from configuration")
-			os.Remove(conf_dir + "/strings/" + string_dir)
-		}
-	
-		//Check if there's an OS descriptor refering this config
-		if _, err := os.Stat(gadget_dir + "/os_desc/" + conf_name); !os.IsNotExist(err) {
-			fmt.Println("\tDeleting link to '" + conf_name + "' from gadgets OS descriptor")
-			os.Remove(gadget_dir + "/os_desc/" + conf_name)
-		}
-		
-		// remove config folder, finally
-		fmt.Println("\tDeleting configuration '" + conf_name + "'")
-		os.Remove(conf_dir)
-	}
-		
-	// remove functions
-	fmt.Println("Removing functions from '" + Gadget_name + "'")
-	os.RemoveAll(gadget_dir + "/functions/")
-	
-	//find string directories in gadget
-	strings_content, _ := ioutil.ReadDir(gadget_dir + "/strings")
-	for _, str := range strings_content {
-		string_dir := str.Name()
-		//Remove string from config
-		fmt.Println("Removing string dir '" + string_dir + "' from " + Gadget_name)
-		os.Remove(gadget_dir + "/strings/" + string_dir)
-	}
-	
-	//And now remove the gadget itself
-	fmt.Println("Removing gadget " + Gadget_name)
-	os.Remove(gadget_dir)
-
-	
-	return nil
-}
-
-func (self USB) CreateGadget() error {
+func InitGadget(settings pb.GadgetSettings) error {
 	//gadget_root := "./test"
 	gadget_root := USB_GADGET_DIR_BASE
-	
+
 	//check if root exists, return error otherwise
 	if _, err := os.Stat(gadget_root); os.IsNotExist(err) {
-		return errors.New("Configfs path for gadget doesn't exist") 
+		return errors.New("Configfs path for gadget doesn't exist")
 	}
-	
+
 	//ToDo: check if UDC is present and usable
-	
+
 	//create gadget folder
 	os.Mkdir(USB_GADGET_DIR, os.ModePerm)
 	//set vendor ID, product ID
-	ioutil.WriteFile(USB_GADGET_DIR+"/idVendor", []byte(self.Vid), os.ModePerm)
-	ioutil.WriteFile(USB_GADGET_DIR+"/idProduct", []byte(self.Pid), os.ModePerm)
-	
+	ioutil.WriteFile(USB_GADGET_DIR+"/idVendor", []byte(settings.Vid), os.ModePerm)
+	ioutil.WriteFile(USB_GADGET_DIR+"/idProduct", []byte(settings.Pid), os.ModePerm)
+
 	//set USB mode to 2.0 and device version to 1.0
 	ioutil.WriteFile(USB_GADGET_DIR+"/bcdUSB", []byte(USB_bcdUSB), os.ModePerm)
 	ioutil.WriteFile(USB_GADGET_DIR+"/bcdDevice", []byte(USB_bcdDevice), os.ModePerm)
-	
+
 	//composite class / subclass / proto (needs single configuration)
 	ioutil.WriteFile(USB_GADGET_DIR+"/bDeviceClass", []byte(USB_bDeviceClass), os.ModePerm)
 	ioutil.WriteFile(USB_GADGET_DIR+"/bDeviceSubClass", []byte(USB_bDeviceSubClass), os.ModePerm)
 	ioutil.WriteFile(USB_GADGET_DIR+"/bDeviceProtocol", []byte(USB_bDeviceProtocol), os.ModePerm)
-	
+
 	// set device descriptions
 	os.Mkdir(USB_GADGET_DIR+"/strings/0x409", os.ModePerm) // English language strings
-	ioutil.WriteFile(USB_GADGET_DIR+"/strings/0x409/serialnumber", []byte(self.Serial), os.ModePerm)
-	ioutil.WriteFile(USB_GADGET_DIR+"/strings/0x409/manufacturer", []byte(self.Manufacturer), os.ModePerm)
-	ioutil.WriteFile(USB_GADGET_DIR+"/strings/0x409/product", []byte(self.Product), os.ModePerm)
-	
+	ioutil.WriteFile(USB_GADGET_DIR+"/strings/0x409/serialnumber", []byte(settings.Serial), os.ModePerm)
+	ioutil.WriteFile(USB_GADGET_DIR+"/strings/0x409/manufacturer", []byte(settings.Manufacturer), os.ModePerm)
+	ioutil.WriteFile(USB_GADGET_DIR+"/strings/0x409/product", []byte(settings.Product), os.ModePerm)
+
 	// create configuration instance (only one, as multiple configs aren't valid for Windows composite devices)
 	os.MkdirAll(USB_GADGET_DIR+"/configs/c.1/strings/0x409", os.ModePerm) // English language strings
 	ioutil.WriteFile(USB_GADGET_DIR+"/configs/c.1/strings/0x409/configuration", []byte("Config 1: Composite"), os.ModePerm)
@@ -212,26 +162,26 @@ func (self USB) CreateGadget() error {
 	ioutil.WriteFile(USB_GADGET_DIR+"/configs/c.1/bmAttributes", []byte(USB_CONFIGURATION_bmAttributes), os.ModePerm)
 
 	// RNDIS has to be the first interface on Composite device for Windows (first function initialized)
-	if self.Use_RNDIS {
+	if settings.Use_RNDIS {
 		os.Mkdir(USB_GADGET_DIR+"/functions/rndis.usb0", os.ModePerm) //create RNDIS function
-		ioutil.WriteFile(USB_GADGET_DIR+"/functions/rndis.usb0/host_addr", []byte(USB_FUNCTION_RNDIS_DEFAULT_host_addr), os.ModePerm)
-		ioutil.WriteFile(USB_GADGET_DIR+"/functions/rndis.usb0/dev_addr", []byte(USB_FUNCTION_RNDIS_DEFAULT_dev_addr), os.ModePerm)
+		ioutil.WriteFile(USB_GADGET_DIR+"/functions/rndis.usb0/host_addr", []byte(settings.RndisSettings.HostAddr), os.ModePerm)
+		ioutil.WriteFile(USB_GADGET_DIR+"/functions/rndis.usb0/dev_addr", []byte(settings.RndisSettings.DevAddr), os.ModePerm)
 
 		/*
-		add OS specific device descriptors to force Windows to load RNDIS drivers
-		=============================================================================
-		Witout this additional descriptors, most Windows system detect the RNDIS interface as "Serial COM port"
-		To prevent this, the Microsoft specific OS descriptors are added in here
-		!! Important:
-		If the device already has been connected to the Windows System without providing the
-		OS descriptor, Windows never asks again for them and thus never installs the RNDIS driver
-		This behavior is driven by creation of an registry hive, the first time a device without 
-		OS descriptors is attached. The key is build like this:
-		
-		HKLM\SYSTEM\CurrentControlSet\Control\usbflags\[USB_VID+USB_PID+bcdRelease\osvc
+			add OS specific device descriptors to force Windows to load RNDIS drivers
+			=============================================================================
+			Witout this additional descriptors, most Windows system detect the RNDIS interface as "Serial COM port"
+			To prevent this, the Microsoft specific OS descriptors are added in here
+			!! Important:
+			If the device already has been connected to the Windows System without providing the
+			OS descriptor, Windows never asks again for them and thus never installs the RNDIS driver
+			This behavior is driven by creation of an registry hive, the first time a device without
+			OS descriptors is attached. The key is build like this:
 
-		To allow Windows to read the OS descriptors again, the according registry hive has to be
-		deleted manually or USB descriptor values have to be cahnged (f.e. USB_PID).
+			HKLM\SYSTEM\CurrentControlSet\Control\usbflags\[USB_VID+USB_PID+bcdRelease\osvc
+
+			To allow Windows to read the OS descriptors again, the according registry hive has to be
+			deleted manually or USB descriptor values have to be cahnged (f.e. USB_PID).
 		*/
 
 		//set OS descriptors for Windows
@@ -244,110 +194,190 @@ func (self USB) CreateGadget() error {
 		//activate function by symlinking to config 1
 		err := os.Symlink(USB_GADGET_DIR+"/functions/rndis.usb0", USB_GADGET_DIR+"/configs/c.1/rndis.usb0")
 		if err != nil {
-			fmt.Println(err)
+			log.Println(err)
 		}
 
 		// add config 1 to OS descriptors
 		err = os.Symlink(USB_GADGET_DIR+"/configs/c.1", USB_GADGET_DIR+"/os_desc/c.1")
 		if err != nil {
-			fmt.Println(err)
+			log.Println(err)
 		}
 	}
-	
-	if self.Use_CDC_ECM {
+
+	if settings.Use_CDC_ECM {
 		os.Mkdir(USB_GADGET_DIR+"/functions/ecm.usb1", os.ModePerm) //create CDC ECM function
-		ioutil.WriteFile(USB_GADGET_DIR+"/functions/ecm.usb1/host_addr", []byte(USB_FUNCTION_CDC_ECM_DEFAULT_host_addr), os.ModePerm)
-		ioutil.WriteFile(USB_GADGET_DIR+"/functions/ecm.usb1/dev_addr", []byte(USB_FUNCTION_CDC_ECM_DEFAULT_dev_addr), os.ModePerm)
-		
+		ioutil.WriteFile(USB_GADGET_DIR+"/functions/ecm.usb1/host_addr", []byte(settings.CdcEcmSettings.HostAddr), os.ModePerm)
+		ioutil.WriteFile(USB_GADGET_DIR+"/functions/ecm.usb1/dev_addr", []byte(settings.CdcEcmSettings.DevAddr), os.ModePerm)
+
 		//activate function by symlinking to config 1
 		err := os.Symlink(USB_GADGET_DIR+"/functions/ecm.usb1", USB_GADGET_DIR+"/configs/c.1/ecm.usb1")
 		if err != nil {
-			fmt.Println(err)
+			log.Println(err)
 		}
 	}
-	
-	if self.Use_SERIAL {
+
+	if settings.Use_SERIAL {
 		os.Mkdir(USB_GADGET_DIR+"/functions/acm.GS0", os.ModePerm) //create ACM function
 
 		//activate function by symlinking to config 1
 		err := os.Symlink(USB_GADGET_DIR+"/functions/acm.GS0", USB_GADGET_DIR+"/configs/c.1/acm.GS0")
 		if err != nil {
-			fmt.Println(err)
+			log.Println(err)
 		}
 
-	
 	}
-	
-	
-	if self.Use_HID_KEYBOARD {
-		funcdir := USB_GADGET_DIR+"/functions/"+USB_FUNCTION_HID_KEYBOARD_name
+
+	if settings.Use_HID_KEYBOARD {
+		funcdir := USB_GADGET_DIR + "/functions/" + USB_FUNCTION_HID_KEYBOARD_name
 		os.Mkdir(funcdir, os.ModePerm) //create HID function for keyboard
-		
-		ioutil.WriteFile(funcdir + "/protocol", []byte(USB_FUNCTION_HID_KEYBOARD_protocol), os.ModePerm)
-		ioutil.WriteFile(funcdir + "/subclass", []byte(USB_FUNCTION_HID_KEYBOARD_subclass), os.ModePerm)
-		ioutil.WriteFile(funcdir + "/report_length", []byte(USB_FUNCTION_HID_KEYBOARD_report_length), os.ModePerm)
-		ioutil.WriteFile(funcdir + "/report_desc", []byte(USB_FUNCTION_HID_KEYBOARD_report_desc), os.ModePerm)
-		
+
+		ioutil.WriteFile(funcdir+"/protocol", []byte(USB_FUNCTION_HID_KEYBOARD_protocol), os.ModePerm)
+		ioutil.WriteFile(funcdir+"/subclass", []byte(USB_FUNCTION_HID_KEYBOARD_subclass), os.ModePerm)
+		ioutil.WriteFile(funcdir+"/report_length", []byte(USB_FUNCTION_HID_KEYBOARD_report_length), os.ModePerm)
+		ioutil.WriteFile(funcdir+"/report_desc", []byte(USB_FUNCTION_HID_KEYBOARD_report_desc), os.ModePerm)
+
 		err := os.Symlink(funcdir, USB_GADGET_DIR+"/configs/c.1/"+USB_FUNCTION_HID_KEYBOARD_name)
 		if err != nil {
-			fmt.Println(err)
+			log.Println(err)
 		}
 	}
-	
-	if self.Use_HID_MOUSE {
-		funcdir := USB_GADGET_DIR+"/functions/"+USB_FUNCTION_HID_MOUSE_name
+
+	if settings.Use_HID_MOUSE {
+		funcdir := USB_GADGET_DIR + "/functions/" + USB_FUNCTION_HID_MOUSE_name
 		os.Mkdir(funcdir, os.ModePerm) //create HID function for mouse
-		
-		ioutil.WriteFile(funcdir + "/protocol", []byte(USB_FUNCTION_HID_MOUSE_protocol), os.ModePerm)
-		ioutil.WriteFile(funcdir + "/subclass", []byte(USB_FUNCTION_HID_MOUSE_subclass), os.ModePerm)
-		ioutil.WriteFile(funcdir + "/report_length", []byte(USB_FUNCTION_HID_MOUSE_report_length), os.ModePerm)
-		ioutil.WriteFile(funcdir + "/report_desc", []byte(USB_FUNCTION_HID_MOUSE_report_desc), os.ModePerm)
-		
+
+		ioutil.WriteFile(funcdir+"/protocol", []byte(USB_FUNCTION_HID_MOUSE_protocol), os.ModePerm)
+		ioutil.WriteFile(funcdir+"/subclass", []byte(USB_FUNCTION_HID_MOUSE_subclass), os.ModePerm)
+		ioutil.WriteFile(funcdir+"/report_length", []byte(USB_FUNCTION_HID_MOUSE_report_length), os.ModePerm)
+		ioutil.WriteFile(funcdir+"/report_desc", []byte(USB_FUNCTION_HID_MOUSE_report_desc), os.ModePerm)
+
 		err := os.Symlink(funcdir, USB_GADGET_DIR+"/configs/c.1/"+USB_FUNCTION_HID_MOUSE_name)
 		if err != nil {
-			fmt.Println(err)
+			log.Println(err)
 		}
 	}
-	
-	if self.Use_HID_RAW {
-		funcdir := USB_GADGET_DIR+"/functions/"+USB_FUNCTION_HID_RAW_name
+
+	if settings.Use_HID_RAW {
+		funcdir := USB_GADGET_DIR + "/functions/" + USB_FUNCTION_HID_RAW_name
 		os.Mkdir(funcdir, os.ModePerm) //create HID function for mouse
-		
-		ioutil.WriteFile(funcdir + "/protocol", []byte(USB_FUNCTION_HID_RAW_protocol), os.ModePerm)
-		ioutil.WriteFile(funcdir + "/subclass", []byte(USB_FUNCTION_HID_RAW_subclass), os.ModePerm)
-		ioutil.WriteFile(funcdir + "/report_length", []byte(USB_FUNCTION_HID_RAW_report_length), os.ModePerm)
-		ioutil.WriteFile(funcdir + "/report_desc", []byte(USB_FUNCTION_HID_RAW_report_desc), os.ModePerm)
-		
+
+		ioutil.WriteFile(funcdir+"/protocol", []byte(USB_FUNCTION_HID_RAW_protocol), os.ModePerm)
+		ioutil.WriteFile(funcdir+"/subclass", []byte(USB_FUNCTION_HID_RAW_subclass), os.ModePerm)
+		ioutil.WriteFile(funcdir+"/report_length", []byte(USB_FUNCTION_HID_RAW_report_length), os.ModePerm)
+		ioutil.WriteFile(funcdir+"/report_desc", []byte(USB_FUNCTION_HID_RAW_report_desc), os.ModePerm)
+
 		err := os.Symlink(funcdir, USB_GADGET_DIR+"/configs/c.1/"+USB_FUNCTION_HID_RAW_name)
 		if err != nil {
-			fmt.Println(err)
+			log.Println(err)
 		}
 	}
-	
-	
+
 	//get UDC driver name and bind to gadget
 	files, err := ioutil.ReadDir("/sys/class/udc")
 	if err != nil {
-		return errors.New("Couldn't find working UDC driver") 
+		return errors.New("Couldn't find working UDC driver")
 	}
 	if len(files) < 1 {
-		return errors.New("Couldn't find working UDC driver") 
+		return errors.New("Couldn't find working UDC driver")
 	}
 	udc_name := files[0].Name()
 	ioutil.WriteFile(USB_GADGET_DIR+"/UDC", []byte(udc_name), os.ModePerm)
-	
+
 	return nil
 }
 
-func New() USB {
-	ust := USB{
-		Vid: "0x1d6b",
-		Pid: "0x1338",
-		Manufacturer: USB_DEFAULT_MANUFACTURER,
-		Product: USB_DEFAULT_PRODUCT,
-		Serial: USB_DEFAULT_SERIAL,
+func DestroyAllGadgets() error {
+	//gadget_root := "./test"
+	gadget_root := USB_GADGET_DIR_BASE
+
+	//check if root exists, return error otherwise
+	if _, err := os.Stat(gadget_root); os.IsNotExist(err) {
+		return errors.New("Configfs path for gadget doesn't exist")
 	}
 
-	return ust
+	gadget_dirs, err := ioutil.ReadDir(gadget_root)
+	if err != nil {
+		return errors.New("No gadgets")
+	}
+
+	for _, gadget_dir_obj := range gadget_dirs {
+		gadget_name := gadget_dir_obj.Name()
+		log.Println("Found gadget: " + gadget_name)
+		err = DestroyGadget(gadget_name)
+		if err != nil {
+			log.Println(err) //don't return, continue with next
+		}
+	}
+
+	return nil
 }
 
+func DestroyGadget(Gadget_name string) error {
+	//gadget_root := "./test"
+	gadget_dir := USB_GADGET_DIR_BASE + "/" + Gadget_name
+
+	//check if root exists, return error otherwise
+	if _, err := os.Stat(USB_GADGET_DIR_BASE); os.IsNotExist(err) {
+		return errors.New("Gadget " + Gadget_name + " doesn't exist")
+	}
+	log.Println("Deconstructing gadget " + Gadget_name + "...")
+
+	//Assure gadget gets unbound from UDC
+	ioutil.WriteFile(gadget_dir+"/UDC", []byte("\x00"), os.ModePerm)
+
+	//Iterate over configurations
+	config_dirs, _ := ioutil.ReadDir(gadget_dir + "/configs")
+	for _, conf_dir_obj := range config_dirs {
+		conf_name := conf_dir_obj.Name()
+		conf_dir := gadget_dir + "/configs/" + conf_name
+		log.Println("Found config: " + conf_name)
+
+		//find linked functions
+		conf_content, _ := ioutil.ReadDir(conf_dir)
+		for _, function := range conf_content {
+			//Remove link from function to config
+			if function.Mode()&os.ModeSymlink > 0 {
+				log.Println("\tRemoving function " + function.Name() + " from config " + conf_name)
+				os.Remove(conf_dir + "/" + function.Name())
+			}
+		}
+
+		//find string directories in config
+		strings_content, _ := ioutil.ReadDir(conf_dir + "/strings")
+		for _, str := range strings_content {
+			string_dir := str.Name()
+			//Remove string from config
+			log.Println("\tRemoving string dir '" + string_dir + "' from configuration")
+			os.Remove(conf_dir + "/strings/" + string_dir)
+		}
+
+		//Check if there's an OS descriptor refering this config
+		if _, err := os.Stat(gadget_dir + "/os_desc/" + conf_name); !os.IsNotExist(err) {
+			log.Println("\tDeleting link to '" + conf_name + "' from gadgets OS descriptor")
+			os.Remove(gadget_dir + "/os_desc/" + conf_name)
+		}
+
+		// remove config folder, finally
+		log.Println("\tDeleting configuration '" + conf_name + "'")
+		os.Remove(conf_dir)
+	}
+
+	// remove functions
+	log.Println("Removing functions from '" + Gadget_name + "'")
+	os.RemoveAll(gadget_dir + "/functions/")
+
+	//find string directories in gadget
+	strings_content, _ := ioutil.ReadDir(gadget_dir + "/strings")
+	for _, str := range strings_content {
+		string_dir := str.Name()
+		//Remove string from config
+		log.Println("Removing string dir '" + string_dir + "' from " + Gadget_name)
+		os.Remove(gadget_dir + "/strings/" + string_dir)
+	}
+
+	//And now remove the gadget itself
+	log.Println("Removing gadget " + Gadget_name)
+	os.Remove(gadget_dir)
+
+	return nil
+}
diff --git a/main.go b/main.go
deleted file mode 100644
index aadbbf8..0000000
--- a/main.go
+++ /dev/null
@@ -1,29 +0,0 @@
-package main
-
-import (
-	"fmt"
-	"./core"
-)
-
-func main() {
-	usb.DestroyAllGadgets()
-
-	usb_gadget := usb.New()
-	
-	usb_gadget.Pid = "0x1234"
-//	usb_gadget.Use_RNDIS = true //2 EP
-//	usb_gadget.Use_CDC_ECM	= true // 2 EP
-//	usb_gadget.Use_HID_KEYBOARD = true //1 EP
-//	usb_gadget.Use_HID_MOUSE = true // 1 EP
-//	usb_gadget.Use_HID_RAW = true //1 EP
-	usb_gadget.Use_SERIAL = true //2 EP
-	
-	fmt.Printf("%+v\n", usb_gadget)
-	
-	
-	err := usb_gadget.CreateGadget()
-	if err != nil {
-		fmt.Print(err)
-	}
-	
-}
diff --git a/service.go b/service.go
new file mode 100644
index 0000000..5f54fc1
--- /dev/null
+++ b/service.go
@@ -0,0 +1,29 @@
+package main
+
+import (
+	"log"
+
+	"./core"
+)
+
+func main() {
+	var err error
+	err = core.CheckLibComposite()
+	if err != nil {
+		log.Fatalf("Couldn't load libcomposite: %v", err)
+	}
+
+	err = core.DestroyAllGadgets()
+	if err != nil {
+		log.Fatalf("Error while rolling back existing USB gadgets: %v", err)
+	}
+
+	err = core.InitDefaultGadgetSettings()
+	if err != nil {
+		log.Fatalf("Error while setting up the default gadget: %v", err)
+	}
+
+	core.InitLed(false) //Set LED to manual triger
+	//core.StartRpcServer("127.0.0.1", "50051") //start gRPC service
+	core.StartRpcServer("", "50051") //start gRPC service
+}