diff --git a/.vscode/launch.json b/.vscode/launch.json
new file mode 100644
index 0000000..1fd2495
--- /dev/null
+++ b/.vscode/launch.json
@@ -0,0 +1,21 @@
+{
+    // 使用 IntelliSense 了解相关属性。 
+    // 悬停以查看现有属性的描述。
+    // 欲了解更多信息，请访问: https://go.microsoft.com/fwlink/?linkid=830387
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "name": "Launch",
+            "type": "go",
+            "request": "launch",
+            "mode": "debug",
+            "remotePath": "",
+            "port": 2345,
+            "host": "127.0.0.1",
+            "program": "${fileDirname}",
+            "env": {},
+            "args": [],
+            "showLog": true
+        }
+    ]
+}
\ No newline at end of file
diff --git a/README.md b/README.md
index 400d682..8c45ae1 100644
--- a/README.md
+++ b/README.md
@@ -1,7 +1,9 @@
 Arremi
 =====
 
-Arremi is a simple router from serial to MIDI
+![Screen Shot](ScreenShot.png)
+
+Arremi is a simple driver/router from serial to MIDI
 
 Now only for OSX
 
diff --git a/ScreenShot.png b/ScreenShot.png
new file mode 100644
index 0000000..9dde4d6
Binary files /dev/null and b/ScreenShot.png differ
diff --git a/backend/backend.go b/backend/backend.go
new file mode 100644
index 0000000..c4ab429
--- /dev/null
+++ b/backend/backend.go
@@ -0,0 +1,55 @@
+package backend
+
+import (
+	"io"
+
+	"github.com/jacobsa/go-serial/serial"
+	"github.com/tonychee7000/Arremi/consts"
+)
+
+var (
+	// MidiDev is a global midi device.
+	MidiDev *MIDIDevice
+
+	// MIDIError check this. if not nil, go exit
+	MIDIError error
+)
+
+func init() {
+	MidiDev, MIDIError = NewMIDIDevice()
+}
+
+// Run called by frontend.
+func Run(chSerialName chan string, ch chan int, errCh chan error) {
+	serialName := <-chSerialName
+
+	sPort, err := serial.Open(serial.OpenOptions{
+		PortName:        "/dev/" + serialName,
+		BaudRate:        consts.SerialBaudrate,
+		DataBits:        8,
+		StopBits:        1,
+		ParityMode:      serial.PARITY_NONE,
+		MinimumReadSize: 3,
+	})
+	if err != nil {
+		errCh <- err
+		return
+	}
+	defer MidiDev.AllNoteOff()
+	defer sPort.Close()
+
+	go func() {
+		_, err := io.Copy(MidiDev, sPort)
+		if err != nil {
+			errCh <- err
+		}
+		ch <- 1
+	}()
+
+	for {
+		select {
+		case <-ch:
+			return
+		}
+	}
+}
diff --git a/backend/backend_test.go b/backend/backend_test.go
new file mode 100644
index 0000000..bb1c64d
--- /dev/null
+++ b/backend/backend_test.go
@@ -0,0 +1,7 @@
+package backend
+
+import "testing"
+
+func TestBackendRun(t *testing.T) {
+
+}
diff --git a/backend/midiDevice.go b/backend/midiDevice.go
new file mode 100644
index 0000000..cfbd7da
--- /dev/null
+++ b/backend/midiDevice.go
@@ -0,0 +1,50 @@
+package backend
+
+import (
+	"github.com/tonychee7000/Arremi/consts"
+	midi "github.com/youpy/go-coremidi"
+)
+
+// MIDIDevice implies a Writer interface.
+type MIDIDevice struct {
+	client midi.Client
+	source midi.Source
+	Signal chan midi.Packet
+}
+
+// NewMIDIDevice construction func
+func NewMIDIDevice() (*MIDIDevice, error) {
+	var mididev = new(MIDIDevice)
+	err := mididev.Init()
+	return mididev, err
+}
+
+// Init the client and source
+func (midiDev *MIDIDevice) Init() error {
+	var err error
+
+	midiDev.Signal = make(chan midi.Packet, 4096)
+	midiDev.client, err = midi.NewClient(consts.ClientName)
+	if err != nil {
+		return err
+	}
+
+	midiDev.source, err = midi.NewSource(midiDev.client, consts.SourceName)
+	return err
+}
+
+func (midiDev *MIDIDevice) Write(p []byte) (int, error) {
+	var pack = midi.NewPacket(p, 0)
+	midiDev.Signal <- pack
+	err := pack.Received(&(midiDev.source))
+	return len(p), err
+}
+
+// AllNoteOff I don't want panic!
+func (midiDev *MIDIDevice) AllNoteOff() {
+	for i := 0; i < 16; i++ {
+		for j := 0; j < 128; j++ {
+			midiDev.Write([]byte{byte(0x90 + i), byte(j), 0})
+		}
+	}
+}
diff --git a/consts/consts.go b/consts/consts.go
new file mode 100644
index 0000000..040e0a1
--- /dev/null
+++ b/consts/consts.go
@@ -0,0 +1,15 @@
+package consts
+
+const (
+	// WindowTitle for display
+	WindowTitle = "Arremi"
+	// ClientName for make a client
+	ClientName = "Arremi"
+	// SourceName for register Source
+	SourceName = "Arremi"
+
+	MIDISignalOn  = "⚪️"
+	MIDISignalOff = "⚫️"
+
+	SerialBaudrate = 31250
+)
diff --git a/debug b/debug
new file mode 100755
index 0000000..4a96bee
Binary files /dev/null and b/debug differ
diff --git a/frontend/window.go b/frontend/window.go
new file mode 100644
index 0000000..2caf2dd
--- /dev/null
+++ b/frontend/window.go
@@ -0,0 +1,154 @@
+package frontend
+
+import (
+	"fmt"
+	"time"
+
+	"regexp"
+
+	"github.com/andlabs/ui"
+	"github.com/tonychee7000/Arremi/consts"
+	"github.com/tonychee7000/Arremi/serialPort"
+	"github.com/tonychee7000/arremi/backend"
+)
+
+// WindowMain is to show the UI
+func WindowMain() {
+	// Let backend stop
+	//var ch = make(chan int)
+
+	var errCh = make(chan error, 0)
+	var chCon = make(chan int, 1)
+	var chSerialName = make(chan string, 1)
+	var serialList []string
+
+	window := ui.NewWindow(consts.WindowTitle, 300, 100, false)
+
+	if backend.MIDIError != nil {
+		ui.MsgBox(window, "MIDI Failure",
+			fmt.Sprint("MIDI driver initialize failed: ", backend.MIDIError))
+		ui.Quit()
+	}
+
+	labelSerialSelection := ui.NewLabel("Serial Port")
+	serialSelection := ui.NewCombobox()
+	buttonRefresh := ui.NewButton("Refresh")
+	buttonRun := ui.NewCheckbox("Run")
+	labelMidiActive := ui.NewLabel("MIDI Active  ")
+	labelMidiSignal := ui.NewLabel(consts.MIDISignalOff)
+	labelHint := ui.NewLabel(
+		fmt.Sprint(
+			"HINT:\nBaudrate of Arduino USB serial port should be set to ",
+			consts.SerialBaudrate, " by using\n\n\tSerial.begin(", consts.SerialBaudrate, ")",
+		),
+	)
+
+	serialList, err := loadSerial(serialSelection, buttonRun)
+
+	if err != nil {
+		ui.MsgBox(window, "Serial Failure",
+			fmt.Sprint("Cannot list serial ports for reason: ", err))
+		ui.Quit()
+	}
+
+	buttonRefresh.OnClicked(func(*ui.Button) {
+		serialList, err = loadSerial(serialSelection, buttonRun)
+		if err != nil {
+			ui.MsgBox(window, "Serial Failure",
+				fmt.Sprint("Cannot list serial ports for reason: ", err))
+			ui.Quit()
+		}
+	})
+
+	buttonRun.OnToggled(func(*ui.Checkbox) {
+		if buttonRun.Checked() {
+			serialSelection.Disable()
+			buttonRefresh.Disable()
+			chSerialName <- serialList[serialSelection.Selected()]
+		} else {
+			serialSelection.Enable()
+			buttonRefresh.Enable()
+			chCon <- 1
+		}
+	})
+
+	mainBox := ui.NewVerticalBox()
+	topBox := ui.NewHorizontalBox()
+	buttomBox := ui.NewHorizontalBox()
+
+	topBox.Append(serialSelection, true)
+	topBox.Append(buttonRefresh, false)
+	topBox.Append(ui.NewLabel("  "), false)
+	topBox.Append(buttonRun, false)
+
+	buttomBox.Append(labelSerialSelection, false)
+	buttomBox.Append(ui.NewHorizontalSeparator(), true)
+	buttomBox.Append(labelMidiActive, false)
+	buttomBox.Append(labelMidiSignal, false)
+
+	mainBox.Append(ui.NewHorizontalBox(), true)
+	mainBox.Append(buttomBox, false)
+	mainBox.Append(topBox, false)
+	mainBox.Append(labelHint, true)
+	mainBox.Append(ui.NewHorizontalBox(), true)
+
+	window.SetMargined(true)
+	window.SetChild(mainBox)
+	window.OnClosing(func(*ui.Window) bool {
+		if buttonRun.Checked() {
+			return false
+		}
+		ui.Quit()
+		return true
+	})
+
+	go func() {
+		for {
+			select {
+			case err := <-errCh:
+				ui.QueueMain(func() {
+					if err != nil &&
+						!regexp.MustCompile("file already closed").MatchString(err.Error()) {
+						ui.MsgBox(window, "Backend Failure", fmt.Sprint(err))
+					}
+					serialSelection.Enable()
+					buttonRefresh.Enable()
+					buttonRun.SetChecked(false)
+					labelMidiSignal.SetText(consts.MIDISignalOff)
+				})
+			case <-backend.MidiDev.Signal:
+				ui.QueueMain(func() {
+					labelMidiSignal.SetText(consts.MIDISignalOn)
+				})
+			case <-time.After(100 * time.Millisecond):
+				ui.QueueMain(func() {
+					labelMidiSignal.SetText(consts.MIDISignalOff)
+				})
+			}
+		}
+	}()
+
+	go func() {
+		for {
+			backend.Run(chSerialName, chCon, errCh)
+		}
+	}()
+
+	window.Show()
+}
+
+func loadSerial(serialSelection *ui.Combobox, buttonRun *ui.Checkbox) ([]string, error) {
+	serialList, err := serialPort.GetSerialPorts()
+
+	if len(serialList) == 0 {
+		buttonRun.Disable()
+		serialSelection.Append("-- No Arduino Found --")
+		serialSelection.Disable()
+	} else {
+		for _, seiral := range serialList {
+			serialSelection.Append(seiral)
+		}
+	}
+	serialSelection.SetSelected(0)
+	return serialList, err
+}
diff --git a/main.go b/main.go
new file mode 100644
index 0000000..420ad8c
--- /dev/null
+++ b/main.go
@@ -0,0 +1,18 @@
+package main
+
+import (
+	"fmt"
+
+	"github.com/andlabs/ui"
+	"github.com/tonychee7000/Arremi/frontend"
+)
+
+func main() {
+	defer func() {
+		fmt.Println("Arremi Exit.")
+	}()
+	err := ui.Main(frontend.WindowMain)
+	if err != nil {
+		fmt.Print("Got error:", err, "\n")
+	}
+}
diff --git a/serialPort/get_serial.go b/serialPort/get_serial.go
new file mode 100644
index 0000000..5109b85
--- /dev/null
+++ b/serialPort/get_serial.go
@@ -0,0 +1,23 @@
+package serialPort
+
+import (
+	"io/ioutil"
+	"regexp"
+)
+
+// GetSerialPorts is to list all serial port for Arduino device.
+func GetSerialPorts() ([]string, error) {
+	f, err := ioutil.ReadDir("/dev")
+	if err != nil {
+		return nil, err
+	}
+
+	var fileList []string
+	for _, file := range f {
+		if regexp.MustCompile("^ttyACM([0-9]+)|^cu.usbmodem").MatchString(file.Name()) {
+			fileList = append(fileList, file.Name())
+		}
+	}
+
+	return fileList, nil
+}
diff --git a/serialPort/serialPort_test.go b/serialPort/serialPort_test.go
new file mode 100644
index 0000000..fe25336
--- /dev/null
+++ b/serialPort/serialPort_test.go
@@ -0,0 +1,17 @@
+package serialPort
+
+import (
+	"testing"
+)
+
+func TestGetSerialPorts(T *testing.T) {
+	portList, err := GetSerialPorts()
+	if err != nil {
+		T.Error("ERROR: ", err, "\n")
+	}
+	T.Log("Show all serial ports")
+	for _, p := range portList {
+		T.Log("\t", p)
+	}
+}
+