rtl8720dn: add support for rtl8720dn

2026-08-14 03:43:42 +00:00 · 2021-06-27 14:28:54 +09:00
parent b53a8a17e7
commit 0bc3702dd0
19 changed files with 10731 additions and 2 deletions
@@ -197,12 +197,14 @@ endif
 	@md5sum ./build/test.hex
 	tinygo build -size short -o ./build/test.hex -target=feather-m4 ./examples/sdcard/tinyfs/
 	@md5sum ./build/test.hex
 	tinygo build -size short -o ./build/test.hex -target=wioterminal ./examples/rtl8720dn/webclient/
 	@md5sum ./build/test.hex
 DRIVERS = $(wildcard */)
 NOTESTS = build examples flash semihosting pcd8544 shiftregister st7789 microphone mcp3008 gps microbitmatrix \
 		hcsr04 ssd1331 ws2812 thermistor apa102 easystepper ssd1351 ili9341 wifinina shifter hub75 \
 		hd44780 buzzer ssd1306 espat l9110x st7735 bmi160 l293x dht keypad4x4 max72xx p1am tone tm1637 \
-		pcf8563 mcp2515 servo sdcard
+		pcf8563 mcp2515 servo sdcard rtl8720dn
 TESTS = $(filter-out $(addsuffix /%,$(NOTESTS)),$(DRIVERS))
 unit-test:
@@ -52,7 +52,7 @@ func main() {
 ## Currently supported devices
-The following 66 devices are supported.
+The following 67 devices are supported.
 | Device Name | Interface Type |
 |----------|-------------|
@@ -100,6 +100,7 @@ The following 66 devices are supported.
 | [PCD8544 display](http://eia.udg.edu/~forest/PCD8544_1.pdf) | SPI |
 | [PCF8563 real time clock](https://www.nxp.com/docs/en/data-sheet/PCF8563.pdf) | I2C |
 | [Resistive Touchscreen (4-wire)](http://ww1.microchip.com/downloads/en/Appnotes/doc8091.pdf) | GPIO |
 | [RTL8720DN 2.4G/5G Dual Bands Wireless and BLE5.0](https://www.seeedstudio.com/Realtek8720DN-2-4G-5G-Dual-Bands-Wireless-and-BLE5-0-Combo-Module-p-4442.html) | UART |
 | [Semihosting](https://wiki.segger.com/Semihosting) | Debug |
 | [Servo](https://learn.sparkfun.com/tutorials/hobby-servo-tutorial/all) | PWM |
 | [Shift register (PISO)](https://en.wikipedia.org/wiki/Shift_register#Parallel-in_serial-out_\(PISO\)) | GPIO |
@@ -0,0 +1,141 @@
 package main
 import (
 	"fmt"
 	"strings"
 	"time"
 	"tinygo.org/x/drivers/net"
 	"tinygo.org/x/drivers/net/tls"
 	"tinygo.org/x/drivers/rtl8720dn"
 )
 // You can override the setting with the init() in another source code.
 // func init() {
 //    ssid = "your-ssid"
 //    password = "your-password"
 //    debug = true
 //    server = "tinygo.org"
 //    test_root_ca = "..."
 // }
 var (
 	ssid     string
 	password string
 	server   string = "www.example.com"
 	debug           = false
 )
 // Set the test_root_ca created by the following command
 // $ openssl s_client -showcerts -verify 5 -connect www.example.com:443 < /dev/null
 var test_root_ca = `-----BEGIN CERTIFICATE-----
 MIIDrzCCApegAwIBAgIQCDvgVpBCRrGhdWrJWZHHSjANBgkqhkiG9w0BAQUFADBh
 MQswCQYDVQQGEwJVUzEVMBMGA1UEChMMRGlnaUNlcnQgSW5jMRkwFwYDVQQLExB3
 d3cuZGlnaWNlcnQuY29tMSAwHgYDVQQDExdEaWdpQ2VydCBHbG9iYWwgUm9vdCBD
 QTAeFw0wNjExMTAwMDAwMDBaFw0zMTExMTAwMDAwMDBaMGExCzAJBgNVBAYTAlVT
 MRUwEwYDVQQKEwxEaWdpQ2VydCBJbmMxGTAXBgNVBAsTEHd3dy5kaWdpY2VydC5j
 b20xIDAeBgNVBAMTF0RpZ2lDZXJ0IEdsb2JhbCBSb290IENBMIIBIjANBgkqhkiG
 9w0BAQEFAAOCAQ8AMIIBCgKCAQEA4jvhEXLeqKTTo1eqUKKPC3eQyaKl7hLOllsB
 CSDMAZOnTjC3U/dDxGkAV53ijSLdhwZAAIEJzs4bg7/fzTtxRuLWZscFs3YnFo97
 nh6Vfe63SKMI2tavegw5BmV/Sl0fvBf4q77uKNd0f3p4mVmFaG5cIzJLv07A6Fpt
 43C/dxC//AH2hdmoRBBYMql1GNXRor5H4idq9Joz+EkIYIvUX7Q6hL+hqkpMfT7P
 T19sdl6gSzeRntwi5m3OFBqOasv+zbMUZBfHWymeMr/y7vrTC0LUq7dBMtoM1O/4
 gdW7jVg/tRvoSSiicNoxBN33shbyTApOB6jtSj1etX+jkMOvJwIDAQABo2MwYTAO
 BgNVHQ8BAf8EBAMCAYYwDwYDVR0TAQH/BAUwAwEB/zAdBgNVHQ4EFgQUA95QNVbR
 TLtm8KPiGxvDl7I90VUwHwYDVR0jBBgwFoAUA95QNVbRTLtm8KPiGxvDl7I90VUw
 DQYJKoZIhvcNAQEFBQADggEBAMucN6pIExIK+t1EnE9SsPTfrgT1eXkIoyQY/Esr
 hMAtudXH/vTBH1jLuG2cenTnmCmrEbXjcKChzUyImZOMkXDiqw8cvpOp/2PV5Adg
 06O/nVsJ8dWO41P0jmP6P6fbtGbfYmbW0W5BjfIttep3Sp+dWOIrWcBAI+0tKIJF
 PnlUkiaY4IBIqDfv8NZ5YBberOgOzW6sRBc4L0na4UU+Krk2U886UAb3LujEV0ls
 YSEY1QSteDwsOoBrp+uvFRTp2InBuThs4pFsiv9kuXclVzDAGySj4dzp30d8tbQk
 CAUw7C29C79Fv1C5qfPrmAESrciIxpg0X40KPMbp1ZWVbd4=
 -----END CERTIFICATE-----
 `
 var buf [0x400]byte
 var lastRequestTime time.Time
 var conn net.Conn
 var adaptor *rtl8720dn.RTL8720DN
 func main() {
 	err := run()
 	for err != nil {
 		fmt.Printf("error: %s\r\n", err.Error())
 		time.Sleep(5 * time.Second)
 	}
 }
 func run() error {
 	rtl, err := setupRTL8720DN()
 	if err != nil {
 		return err
 	}
 	rtl.SetRootCA(&test_root_ca)
 	net.UseDriver(rtl)
 	err = rtl.ConnectToAP(ssid, password)
 	if err != nil {
 		return err
 	}
 	ip, subnet, gateway, err := rtl.GetIP()
 	if err != nil {
 		return err
 	}
 	fmt.Printf("IP Address : %s\r\n", ip)
 	fmt.Printf("Mask       : %s\r\n", subnet)
 	fmt.Printf("Gateway    : %s\r\n", gateway)
 	cnt := 0
 	for {
 		readConnection()
 		if time.Now().Sub(lastRequestTime).Milliseconds() >= 10000 {
 			makeHTTPSRequest()
 			cnt++
 			fmt.Printf("-------- %d --------\r\n", cnt)
 		}
 	}
 }
 func readConnection() {
 	if conn != nil {
 		for n, err := conn.Read(buf[:]); n > 0; n, err = conn.Read(buf[:]) {
 			if err != nil {
 				println("Read error: " + err.Error())
 			} else {
 				print(string(buf[0:n]))
 			}
 		}
 	}
 }
 func makeHTTPSRequest() {
 	var err error
 	if conn != nil {
 		conn.Close()
 	}
 	message("\r\n---------------\r\nDialing TCP connection")
 	conn, err = tls.Dial("tcp", server, nil)
 	for ; err != nil; conn, err = tls.Dial("tcp", server, nil) {
 		message("Connection failed: " + err.Error())
 		time.Sleep(5 * time.Second)
 	}
 	println("Connected!\r")
 	print("Sending HTTPS request...")
 	fmt.Fprintln(conn, "GET / HTTP/1.1")
 	fmt.Fprintln(conn, "Host:", strings.Split(server, ":")[0])
 	fmt.Fprintln(conn, "User-Agent: TinyGo")
 	fmt.Fprintln(conn, "Connection: close")
 	fmt.Fprintln(conn)
 	println("Sent!\r\n\r")
 	lastRequestTime = time.Now()
 }
 func message(msg string) {
 	println(msg, "\r")
 }
@@ -0,0 +1,71 @@
 // +build wioterminal
 package main
 import (
 	"device/sam"
 	"machine"
 	"runtime/interrupt"
 	"time"
 	"tinygo.org/x/drivers/rtl8720dn"
 )
 var (
 	uart UARTx
 )
 func handleInterrupt(interrupt.Interrupt) {
 	// should reset IRQ
 	uart.Receive(byte((uart.Bus.DATA.Get() & 0xFF)))
 	uart.Bus.INTFLAG.SetBits(sam.SERCOM_USART_INT_INTFLAG_RXC)
 }
 func setupRTL8720DN() (*rtl8720dn.RTL8720DN, error) {
 	machine.RTL8720D_CHIP_PU.Configure(machine.PinConfig{Mode: machine.PinOutput})
 	machine.RTL8720D_CHIP_PU.Low()
 	time.Sleep(100 * time.Millisecond)
 	machine.RTL8720D_CHIP_PU.High()
 	time.Sleep(1000 * time.Millisecond)
 	waitSerial()
 	uart = UARTx{
 		UART: &machine.UART{
 			Buffer: machine.NewRingBuffer(),
 			Bus:    sam.SERCOM0_USART_INT,
 			SERCOM: 0,
 		},
 	}
 	uart.Interrupt = interrupt.New(sam.IRQ_SERCOM0_2, handleInterrupt)
 	uart.Configure(machine.UARTConfig{TX: machine.PB24, RX: machine.PC24, BaudRate: 614400})
 	rtl := rtl8720dn.New(uart)
 	rtl.Debug(debug)
 	_, err := rtl.Rpc_tcpip_adapter_init()
 	if err != nil {
 		return nil, err
 	}
 	return rtl, nil
 }
 // Wait for user to open serial console
 func waitSerial() {
 	for !machine.Serial.DTR() {
 		time.Sleep(100 * time.Millisecond)
 	}
 }
 type UARTx struct {
 	*machine.UART
 }
 func (u UARTx) Read(p []byte) (n int, err error) {
 	if u.Buffered() == 0 {
 		time.Sleep(1 * time.Millisecond)
 		return 0, nil
 	}
 	return u.UART.Read(p)
 }
@@ -0,0 +1,143 @@
 package main
 import (
 	"fmt"
 	"image/color"
 	"time"
 	"tinygo.org/x/drivers/net"
 	"tinygo.org/x/drivers/rtl8720dn"
 	"tinygo.org/x/tinyfont/proggy"
 	"tinygo.org/x/tinyterm"
 )
 // You can override the setting with the init() in another source code.
 // func init() {
 //    ssid = "your-ssid"
 //    password = "your-password"
 //    debug = true
 //    server = "tinygo.org"
 // }
 var (
 	ssid     string
 	password string
 	server   string = "tinygo.org"
 	debug           = false
 )
 var (
 	terminal = tinyterm.NewTerminal(display)
 	black = color.RGBA{0, 0, 0, 255}
 	white = color.RGBA{255, 255, 255, 255}
 	red   = color.RGBA{255, 0, 0, 255}
 	blue  = color.RGBA{0, 0, 255, 255}
 	green = color.RGBA{0, 255, 0, 255}
 	font = &proggy.TinySZ8pt7b
 )
 var buf [0x400]byte
 var lastRequestTime time.Time
 var conn net.Conn
 var adaptor *rtl8720dn.RTL8720DN
 func main() {
 	display.FillScreen(black)
 	backlight.High()
 	terminal.Configure(&tinyterm.Config{
 		Font:       font,
 		FontHeight: 10,
 		FontOffset: 6,
 	})
 	err := run()
 	for err != nil {
 		fmt.Fprintf(terminal, "error: %s\r\n", err.Error())
 		time.Sleep(5 * time.Second)
 	}
 }
 func run() error {
 	fmt.Fprintf(terminal, "setupRTL8720DN()\r\n")
 	rtl, err := setupRTL8720DN()
 	if err != nil {
 		return err
 	}
 	net.UseDriver(rtl)
 	fmt.Fprintf(terminal, "ConnectToAP()\r\n")
 	err = rtl.ConnectToAP(ssid, password)
 	if err != nil {
 		return err
 	}
 	fmt.Fprintf(terminal, "connected\r\n\r\n")
 	ip, subnet, gateway, err := rtl.GetIP()
 	if err != nil {
 		return err
 	}
 	fmt.Fprintf(terminal, "IP Address : %s\r\n", ip)
 	fmt.Fprintf(terminal, "Mask       : %s\r\n", subnet)
 	fmt.Fprintf(terminal, "Gateway    : %s\r\n", gateway)
 	cnt := 0
 	for {
 		readConnection()
 		if time.Now().Sub(lastRequestTime).Milliseconds() >= 10000 {
 			makeHTTPRequest()
 			cnt++
 			fmt.Fprintf(terminal, "-------- %d --------\r\n", cnt)
 		}
 	}
 }
 func readConnection() {
 	if conn != nil {
 		for n, err := conn.Read(buf[:]); n > 0; n, err = conn.Read(buf[:]) {
 			if err != nil {
 				fmt.Fprintf(terminal, "Read error: "+err.Error()+"\r\n")
 			} else {
 				fmt.Fprintf(terminal, string(buf[0:n]))
 			}
 		}
 	}
 }
 func makeHTTPRequest() {
 	var err error
 	if conn != nil {
 		conn.Close()
 	}
 	// make TCP connection
 	ip := net.ParseIP(server)
 	raddr := &net.TCPAddr{IP: ip, Port: 80}
 	laddr := &net.TCPAddr{Port: 8080}
 	message("\r\n---------------\r\nDialing TCP connection")
 	conn, err = net.DialTCP("tcp", laddr, raddr)
 	for ; err != nil; conn, err = net.DialTCP("tcp", laddr, raddr) {
 		message("Connection failed: " + err.Error())
 		time.Sleep(5 * time.Second)
 	}
 	fmt.Fprintf(terminal, "Connected!\r\n")
 	fmt.Fprintf(terminal, "Sending HTTP request...")
 	fmt.Fprintln(conn, "GET / HTTP/1.1")
 	fmt.Fprintln(conn, "Host:", server)
 	fmt.Fprintln(conn, "User-Agent: TinyGo")
 	fmt.Fprintln(conn, "Connection: close")
 	fmt.Fprintln(conn)
 	fmt.Fprintf(terminal, "Sent!\r\n\r\n")
 	lastRequestTime = time.Now()
 }
 func message(msg string) {
 	fmt.Fprintf(terminal, "%s\r\n", msg)
 }
@@ -0,0 +1,97 @@
 // +build wioterminal
 package main
 import (
 	"device/sam"
 	"machine"
 	"runtime/interrupt"
 	"time"
 	"tinygo.org/x/drivers/ili9341"
 	"tinygo.org/x/drivers/rtl8720dn"
 )
 var (
 	uart UARTx
 )
 var (
 	display = ili9341.NewSPI(
 		machine.SPI3,
 		machine.LCD_DC,
 		machine.LCD_SS_PIN,
 		machine.LCD_RESET,
 	)
 	backlight = machine.LCD_BACKLIGHT
 )
 func init() {
 	machine.SPI3.Configure(machine.SPIConfig{
 		SCK:       machine.LCD_SCK_PIN,
 		SDO:       machine.LCD_SDO_PIN,
 		SDI:       machine.LCD_SDI_PIN,
 		Frequency: 40000000,
 	})
 	display.Configure(ili9341.Config{})
 	backlight.Configure(machine.PinConfig{machine.PinOutput})
 }
 func handleInterrupt(interrupt.Interrupt) {
 	// should reset IRQ
 	uart.Receive(byte((uart.Bus.DATA.Get() & 0xFF)))
 	uart.Bus.INTFLAG.SetBits(sam.SERCOM_USART_INT_INTFLAG_RXC)
 }
 func setupRTL8720DN() (*rtl8720dn.RTL8720DN, error) {
 	machine.RTL8720D_CHIP_PU.Configure(machine.PinConfig{Mode: machine.PinOutput})
 	machine.RTL8720D_CHIP_PU.Low()
 	time.Sleep(100 * time.Millisecond)
 	machine.RTL8720D_CHIP_PU.High()
 	time.Sleep(1000 * time.Millisecond)
 	if debug {
 		waitSerial()
 	}
 	uart = UARTx{
 		UART: &machine.UART{
 			Buffer: machine.NewRingBuffer(),
 			Bus:    sam.SERCOM0_USART_INT,
 			SERCOM: 0,
 		},
 	}
 	uart.Interrupt = interrupt.New(sam.IRQ_SERCOM0_2, handleInterrupt)
 	uart.Configure(machine.UARTConfig{TX: machine.PB24, RX: machine.PC24, BaudRate: 614400})
 	rtl := rtl8720dn.New(uart)
 	rtl.Debug(debug)
 	_, err := rtl.Rpc_tcpip_adapter_init()
 	if err != nil {
 		return nil, err
 	}
 	return rtl, nil
 }
 // Wait for user to open serial console
 func waitSerial() {
 	for !machine.Serial.DTR() {
 		time.Sleep(100 * time.Millisecond)
 	}
 }
 type UARTx struct {
 	*machine.UART
 }
 func (u UARTx) Read(p []byte) (n int, err error) {
 	if u.Buffered() == 0 {
 		time.Sleep(1 * time.Millisecond)
 		return 0, nil
 	}
 	return u.UART.Read(p)
 }
@@ -0,0 +1,116 @@
 package main
 import (
 	"fmt"
 	"time"
 	"tinygo.org/x/drivers/net"
 	"tinygo.org/x/drivers/rtl8720dn"
 )
 // You can override the setting with the init() in another source code.
 // func init() {
 //    ssid = "your-ssid"
 //    password = "your-password"
 //    debug = true
 //    server = "tinygo.org"
 // }
 var (
 	ssid     string
 	password string
 	server   string = "tinygo.org"
 	debug           = false
 )
 var buf [0x400]byte
 var lastRequestTime time.Time
 var conn net.Conn
 var adaptor *rtl8720dn.RTL8720DN
 func main() {
 	err := run()
 	for err != nil {
 		fmt.Printf("error: %s\r\n", err.Error())
 		time.Sleep(5 * time.Second)
 	}
 }
 func run() error {
 	rtl, err := setupRTL8720DN()
 	if err != nil {
 		return err
 	}
 	net.UseDriver(rtl)
 	err = rtl.ConnectToAP(ssid, password)
 	if err != nil {
 		return err
 	}
 	ip, subnet, gateway, err := rtl.GetIP()
 	if err != nil {
 		return err
 	}
 	fmt.Printf("IP Address : %s\r\n", ip)
 	fmt.Printf("Mask       : %s\r\n", subnet)
 	fmt.Printf("Gateway    : %s\r\n", gateway)
 	cnt := 0
 	for {
 		readConnection()
 		if time.Now().Sub(lastRequestTime).Milliseconds() >= 10000 {
 			makeHTTPRequest()
 			cnt++
 			fmt.Printf("-------- %d --------\r\n", cnt)
 		}
 	}
 }
 func readConnection() {
 	if conn != nil {
 		for n, err := conn.Read(buf[:]); n > 0; n, err = conn.Read(buf[:]) {
 			if err != nil {
 				println("Read error: " + err.Error())
 			} else {
 				print(string(buf[0:n]))
 			}
 		}
 	}
 }
 func makeHTTPRequest() {
 	var err error
 	if conn != nil {
 		conn.Close()
 	}
 	// make TCP connection
 	ip := net.ParseIP(server)
 	raddr := &net.TCPAddr{IP: ip, Port: 80}
 	laddr := &net.TCPAddr{Port: 8080}
 	message("\r\n---------------\r\nDialing TCP connection")
 	conn, err = net.DialTCP("tcp", laddr, raddr)
 	for ; err != nil; conn, err = net.DialTCP("tcp", laddr, raddr) {
 		message("Connection failed: " + err.Error())
 		time.Sleep(5 * time.Second)
 	}
 	println("Connected!\r")
 	print("Sending HTTP request...")
 	fmt.Fprintln(conn, "GET / HTTP/1.1")
 	fmt.Fprintln(conn, "Host:", server)
 	fmt.Fprintln(conn, "User-Agent: TinyGo")
 	fmt.Fprintln(conn, "Connection: close")
 	fmt.Fprintln(conn)
 	println("Sent!\r\n\r")
 	lastRequestTime = time.Now()
 }
 func message(msg string) {
 	println(msg, "\r")
 }
@@ -0,0 +1,71 @@
 // +build wioterminal
 package main
 import (
 	"device/sam"
 	"machine"
 	"runtime/interrupt"
 	"time"
 	"tinygo.org/x/drivers/rtl8720dn"
 )
 var (
 	uart UARTx
 )
 func handleInterrupt(interrupt.Interrupt) {
 	// should reset IRQ
 	uart.Receive(byte((uart.Bus.DATA.Get() & 0xFF)))
 	uart.Bus.INTFLAG.SetBits(sam.SERCOM_USART_INT_INTFLAG_RXC)
 }
 func setupRTL8720DN() (*rtl8720dn.RTL8720DN, error) {
 	machine.RTL8720D_CHIP_PU.Configure(machine.PinConfig{Mode: machine.PinOutput})
 	machine.RTL8720D_CHIP_PU.Low()
 	time.Sleep(100 * time.Millisecond)
 	machine.RTL8720D_CHIP_PU.High()
 	time.Sleep(1000 * time.Millisecond)
 	waitSerial()
 	uart = UARTx{
 		UART: &machine.UART{
 			Buffer: machine.NewRingBuffer(),
 			Bus:    sam.SERCOM0_USART_INT,
 			SERCOM: 0,
 		},
 	}
 	uart.Interrupt = interrupt.New(sam.IRQ_SERCOM0_2, handleInterrupt)
 	uart.Configure(machine.UARTConfig{TX: machine.PB24, RX: machine.PC24, BaudRate: 614400})
 	rtl := rtl8720dn.New(uart)
 	rtl.Debug(debug)
 	_, err := rtl.Rpc_tcpip_adapter_init()
 	if err != nil {
 		return nil, err
 	}
 	return rtl, nil
 }
 // Wait for user to open serial console
 func waitSerial() {
 	for !machine.Serial.DTR() {
 		time.Sleep(100 * time.Millisecond)
 	}
 }
 type UARTx struct {
 	*machine.UART
 }
 func (u UARTx) Read(p []byte) (n int, err error) {
 	if u.Buffered() == 0 {
 		time.Sleep(1 * time.Millisecond)
 		return 0, nil
 	}
 	return u.UART.Read(p)
 }
@@ -6,4 +6,6 @@ require (
 	github.com/eclipse/paho.mqtt.golang v1.2.0
 	github.com/frankban/quicktest v1.10.2
 	github.com/tinygo-org/tinyfs v0.0.0-20210620184125-5b00ebcf68bb
 	tinygo.org/x/tinyfont v0.2.1 // indirect
 	tinygo.org/x/tinyterm v0.1.0 // indirect
 )
@@ -1,3 +1,4 @@
 github.com/bgould/http v0.0.0-20190627042742-d268792bdee7/go.mod h1:BTqvVegvwifopl4KTEDth6Zezs9eR+lCWhvGKvkxJHE=
 github.com/eclipse/paho.mqtt.golang v1.2.0 h1:1F8mhG9+aO5/xpdtFkW4SxOJB67ukuDC3t2y2qayIX0=
 github.com/eclipse/paho.mqtt.golang v1.2.0/go.mod h1:H9keYFcgq3Qr5OUJm/JZI/i6U7joQ8SYLhZwfeOo6Ts=
 github.com/frankban/quicktest v1.10.2 h1:19ARM85nVi4xH7xPXuc5eM/udya5ieh7b/Sv+d844Tk=
@@ -15,6 +16,13 @@ github.com/tinygo-org/tinyfs v0.0.0-20210514090915-924e60a7bcf8 h1:pYwuKe1XuNeJn
 github.com/tinygo-org/tinyfs v0.0.0-20210514090915-924e60a7bcf8/go.mod h1:HGuyo42bGd1zWSuS1gwgyyjN36ZZMlEpwM0vSrglmXc=
 github.com/tinygo-org/tinyfs v0.0.0-20210620184125-5b00ebcf68bb h1:lgwaY6CLUvZoH4DMwHn3vKjYRx6npRX1FwjWuJEpZao=
 github.com/tinygo-org/tinyfs v0.0.0-20210620184125-5b00ebcf68bb/go.mod h1:HGuyo42bGd1zWSuS1gwgyyjN36ZZMlEpwM0vSrglmXc=
 github.com/valyala/fastjson v1.6.3/go.mod h1:CLCAqky6SMuOcxStkYQvblddUtoRxhYMGLrsQns1aXY=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543 h1:E7g+9GITq07hpfrRu66IVDexMakfv52eLZ2CXBWiKr4=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 tinygo.org/x/drivers v0.14.0/go.mod h1:uT2svMq3EpBZpKkGO+NQHjxjGf1f42ra4OnMMwQL2aI=
 tinygo.org/x/drivers v0.15.1/go.mod h1:uT2svMq3EpBZpKkGO+NQHjxjGf1f42ra4OnMMwQL2aI=
 tinygo.org/x/drivers v0.16.0/go.mod h1:uT2svMq3EpBZpKkGO+NQHjxjGf1f42ra4OnMMwQL2aI=
 tinygo.org/x/tinyfont v0.2.1 h1:FAaemBzw8wsfhAtG6fWW+QjyWw/K8YqEeiWo4N1pv4o=
 tinygo.org/x/tinyfont v0.2.1/go.mod h1:eLqnYSrFRjt5STxWaMeOWJTzrKhXqpWw7nU3bPfKOAM=
 tinygo.org/x/tinyterm v0.1.0 h1:80i+j+KWoxCFa/Xfp6pWbh79x+8zUdMXC1vaKj2QhkY=
 tinygo.org/x/tinyterm v0.1.0/go.mod h1:/DDhNnGwNF2/tNgHywvyZuCGnbH3ov49Z/6e8LPLRR4=
@@ -0,0 +1,21 @@
 # RTL8720DN Driver
 This package provides a driver to use a separate connected WiFi processor `RTL8720DN` for TCP/UDP communication.
 At this time, only part of TCP is supported.
 ## Using th RTL8720DN Driver
 For now, it is only available for the `RTL8720DN` on `Wio Terminal`.
 You can try the following command.
 ```
 $ tinygo flash --target wioterminal --size short ./examples/rtl8720dn/webclient/
 $ tinygo flash --target wioterminal --size short ./examples/rtl8720dn/tlsclient/
 ```
 ## RTL8720DN Firmware
 Follow the steps below to update.
 The firmware must be version 2.1.2 or later.
 https://wiki.seeedstudio.com/Wio-Terminal-Network-Overview/
@@ -0,0 +1,35 @@
 package rtl8720dn
 // https://github.com/EmbeddedRPC/erpc/blob/develop/erpc_python/erpc/crc16.py
 const (
 	crcStart = 0xEF4A
 )
 var table = [256]uint16{
 	0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50A5, 0x60C6, 0x70E7, 0x8108, 0x9129, 0xA14A, 0xB16B, 0xC18C, 0xD1AD, 0xE1CE, 0xF1EF,
 	0x1231, 0x0210, 0x3273, 0x2252, 0x52B5, 0x4294, 0x72F7, 0x62D6, 0x9339, 0x8318, 0xB37B, 0xA35A, 0xD3BD, 0xC39C, 0xF3FF, 0xE3DE,
 	0x2462, 0x3443, 0x0420, 0x1401, 0x64E6, 0x74C7, 0x44A4, 0x5485, 0xA56A, 0xB54B, 0x8528, 0x9509, 0xE5EE, 0xF5CF, 0xC5AC, 0xD58D,
 	0x3653, 0x2672, 0x1611, 0x0630, 0x76D7, 0x66F6, 0x5695, 0x46B4, 0xB75B, 0xA77A, 0x9719, 0x8738, 0xF7DF, 0xE7FE, 0xD79D, 0xC7BC,
 	0x48C4, 0x58E5, 0x6886, 0x78A7, 0x0840, 0x1861, 0x2802, 0x3823, 0xC9CC, 0xD9ED, 0xE98E, 0xF9AF, 0x8948, 0x9969, 0xA90A, 0xB92B,
 	0x5AF5, 0x4AD4, 0x7AB7, 0x6A96, 0x1A71, 0x0A50, 0x3A33, 0x2A12, 0xDBFD, 0xCBDC, 0xFBBF, 0xEB9E, 0x9B79, 0x8B58, 0xBB3B, 0xAB1A,
 	0x6CA6, 0x7C87, 0x4CE4, 0x5CC5, 0x2C22, 0x3C03, 0x0C60, 0x1C41, 0xEDAE, 0xFD8F, 0xCDEC, 0xDDCD, 0xAD2A, 0xBD0B, 0x8D68, 0x9D49,
 	0x7E97, 0x6EB6, 0x5ED5, 0x4EF4, 0x3E13, 0x2E32, 0x1E51, 0x0E70, 0xFF9F, 0xEFBE, 0xDFDD, 0xCFFC, 0xBF1B, 0xAF3A, 0x9F59, 0x8F78,
 	0x9188, 0x81A9, 0xB1CA, 0xA1EB, 0xD10C, 0xC12D, 0xF14E, 0xE16F, 0x1080, 0x00A1, 0x30C2, 0x20E3, 0x5004, 0x4025, 0x7046, 0x6067,
 	0x83B9, 0x9398, 0xA3FB, 0xB3DA, 0xC33D, 0xD31C, 0xE37F, 0xF35E, 0x02B1, 0x1290, 0x22F3, 0x32D2, 0x4235, 0x5214, 0x6277, 0x7256,
 	0xB5EA, 0xA5CB, 0x95A8, 0x8589, 0xF56E, 0xE54F, 0xD52C, 0xC50D, 0x34E2, 0x24C3, 0x14A0, 0x0481, 0x7466, 0x6447, 0x5424, 0x4405,
 	0xA7DB, 0xB7FA, 0x8799, 0x97B8, 0xE75F, 0xF77E, 0xC71D, 0xD73C, 0x26D3, 0x36F2, 0x0691, 0x16B0, 0x6657, 0x7676, 0x4615, 0x5634,
 	0xD94C, 0xC96D, 0xF90E, 0xE92F, 0x99C8, 0x89E9, 0xB98A, 0xA9AB, 0x5844, 0x4865, 0x7806, 0x6827, 0x18C0, 0x08E1, 0x3882, 0x28A3,
 	0xCB7D, 0xDB5C, 0xEB3F, 0xFB1E, 0x8BF9, 0x9BD8, 0xABBB, 0xBB9A, 0x4A75, 0x5A54, 0x6A37, 0x7A16, 0x0AF1, 0x1AD0, 0x2AB3, 0x3A92,
 	0xFD2E, 0xED0F, 0xDD6C, 0xCD4D, 0xBDAA, 0xAD8B, 0x9DE8, 0x8DC9, 0x7C26, 0x6C07, 0x5C64, 0x4C45, 0x3CA2, 0x2C83, 0x1CE0, 0x0CC1,
 	0xEF1F, 0xFF3E, 0xCF5D, 0xDF7C, 0xAF9B, 0xBFBA, 0x8FD9, 0x9FF8, 0x6E17, 0x7E36, 0x4E55, 0x5E74, 0x2E93, 0x3EB2, 0x0ED1, 0x1EF0,
 }
 func computeCRC16(data []byte) uint16 {
 	crc := uint16(crcStart)
 	for _, d := range data {
 		crc = ((crc << 8) ^ table[((crc>>8)^uint16(d))&0xFF]) & 0xFFFF
 	}
 	return crc
 }
@@ -0,0 +1,278 @@
 package rtl8720dn
 import (
 	"fmt"
 	"strconv"
 )
 // Here is the implementation of tinygo-org/x/drivers/net.DeviceDriver.
 func (r *RTL8720DN) GetDNS(domain string) (string, error) {
 	if r.debug {
 		fmt.Printf("GetDNS(%q)\r\n", domain)
 	}
 	ipaddr := [4]byte{}
 	_, err := r.Rpc_netconn_gethostbyname(domain, ipaddr[:])
 	if err != nil {
 		return "", err
 	}
 	ret, err := fmt.Sprintf("%d.%d.%d.%d", ipaddr[0], ipaddr[1], ipaddr[2], ipaddr[3]), nil
 	if r.debug {
 		fmt.Printf("-> %s\r\n", ret)
 		fmt.Printf("-> %02X.%02X.%02X.%02X\r\n", ipaddr[0], ipaddr[1], ipaddr[2], ipaddr[3])
 	}
 	return ret, err
 }
 func (r *RTL8720DN) ConnectTCPSocket(addr, port string) error {
 	if r.debug {
 		fmt.Printf("ConnectTCPSocket(%q, %q)\r\n", addr, port)
 	}
 	ipaddr := [4]byte{}
 	_, err := r.Rpc_netconn_gethostbyname(addr, ipaddr[:])
 	if err != nil {
 		return err
 	}
 	portNum, err := strconv.ParseUint(port, 0, 0)
 	if err != nil {
 		return err
 	}
 	socket, err := r.Rpc_lwip_socket(0x02, 0x01, 0x00)
 	if err != nil {
 		return err
 	}
 	r.socket = socket
 	r.connectionType = ConnectionTypeTCP
 	_, err = r.Rpc_lwip_fcntl(socket, 0x00000003, 0x00000000)
 	if err != nil {
 		return err
 	}
 	_, err = r.Rpc_lwip_fcntl(socket, 0x00000004, 0x00000001)
 	if err != nil {
 		return err
 	}
 	name := []byte{0x00, 0x02, 0x00, 0x50, 0xC0, 0xA8, 0x01, 0x76, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}
 	name[2] = byte(portNum >> 8)
 	name[3] = byte(portNum)
 	name[4] = byte(ipaddr[0])
 	name[5] = byte(ipaddr[1])
 	name[6] = byte(ipaddr[2])
 	name[7] = byte(ipaddr[3])
 	_, err = r.Rpc_lwip_connect(socket, name, uint32(len(name)))
 	if err != nil {
 		return err
 	}
 	readset := []byte{}
 	writeset := []byte{0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}
 	exceptset := []byte{}
 	timeout := []byte{}
 	_, err = r.Rpc_lwip_select(0x01, readset, writeset, exceptset, timeout)
 	if err != nil {
 		return err
 	}
 	optlen := uint32(4)
 	_, err = r.Rpc_lwip_getsockopt(socket, 0x00000FFF, 0x00001007, []byte{0xA5, 0xA5, 0xA5, 0xA5}, nil, optlen)
 	if err != nil {
 		return err
 	}
 	_, err = r.Rpc_lwip_fcntl(socket, 0x00000003, 0x00000000)
 	if err != nil {
 		return err
 	}
 	_, err = r.Rpc_lwip_fcntl(socket, 0x00000004, 0x00000000)
 	if err != nil {
 		return err
 	}
 	readset = []byte{}
 	writeset = []byte{0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}
 	exceptset = []byte{}
 	timeout = []byte{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x40, 0x42, 0x0F, 0x00, 0xFF, 0xFF, 0xFF, 0xFF}
 	_, err = r.Rpc_lwip_select(0x01, readset, writeset, exceptset, timeout)
 	if err != nil {
 		return err
 	}
 	return nil
 }
 func (r *RTL8720DN) ConnectSSLSocket(addr, port string) error {
 	if r.debug {
 		fmt.Printf("ConnectSSLSocket(%q, %q)\r\n", addr, port)
 	}
 	client, err := r.Rpc_wifi_ssl_client_create()
 	if err != nil {
 		return err
 	}
 	r.client = client
 	r.connectionType = ConnectionTypeTLS
 	err = r.Rpc_wifi_ssl_init(client)
 	if err != nil {
 		return err
 	}
 	err = r.Rpc_wifi_ssl_set_timeout(client, 0x0001D4C0)
 	if err != nil {
 		return err
 	}
 	_, err = r.Rpc_wifi_ssl_set_rootCA(client, *r.root_ca)
 	if err != nil {
 		return err
 	}
 	// TODO: use port
 	_, err = r.Rpc_wifi_start_ssl_client(client, addr, 443, 0x0001D4C0)
 	if err != nil {
 		return err
 	}
 	_, err = r.Rpc_wifi_ssl_get_socket(client)
 	if err != nil {
 		return err
 	}
 	return nil
 }
 func (r *RTL8720DN) ConnectUDPSocket(addr, sendport, listenport string) error {
 	if r.debug {
 		fmt.Printf("ConnectUDPSocket(%q, %q, %q)\r\n", addr, sendport, listenport)
 	}
 	fmt.Printf("not implemented yet\r\n")
 	return nil
 }
 func (r *RTL8720DN) DisconnectSocket() error {
 	if r.debug {
 		fmt.Printf("DisconnectSocket()\r\n")
 	}
 	switch r.connectionType {
 	case ConnectionTypeTCP:
 		_, err := r.Rpc_lwip_close(r.socket)
 		if err != nil {
 			return err
 		}
 	case ConnectionTypeTLS:
 		err := r.Rpc_wifi_stop_ssl_socket(r.client)
 		if err != nil {
 			return err
 		}
 		err = r.Rpc_wifi_ssl_client_destroy(r.client)
 		if err != nil {
 			return err
 		}
 	default:
 	}
 	r.connectionType = ConnectionTypeNone
 	return nil
 }
 func (r *RTL8720DN) StartSocketSend(size int) error {
 	if r.debug {
 		fmt.Printf("StartSocketSend(%d)\r\n", size)
 	}
 	// No implementation required
 	return nil
 }
 func (r *RTL8720DN) Write(b []byte) (n int, err error) {
 	if r.debug {
 		fmt.Printf("Write(%#v)\r\n", b)
 	}
 	switch r.connectionType {
 	case ConnectionTypeTCP:
 		sn, err := r.Rpc_lwip_send(r.socket, b, 0x00000008)
 		if err != nil {
 			return 0, err
 		}
 		n = int(sn)
 	case ConnectionTypeTLS:
 		sn, err := r.Rpc_wifi_send_ssl_data(r.client, b, uint16(len(b)))
 		if err != nil {
 			return 0, err
 		}
 		n = int(sn)
 	default:
 		return 0, nil
 	}
 	return n, nil
 }
 func (r *RTL8720DN) ReadSocket(b []byte) (n int, err error) {
 	if r.debug {
 		//fmt.Printf("ReadSocket(b)\r\n")
 	}
 	if r.connectionType == ConnectionTypeNone {
 		return 0, nil
 	}
 	switch r.connectionType {
 	case ConnectionTypeTCP:
 		nn, err := r.Rpc_lwip_recv(r.socket, b, uint32(len(b)), 0x00000008, 0x00002800)
 		if err != nil {
 			return 0, err
 		}
 		if nn == -1 {
 			return 0, nil
 		} else if nn == 0 {
 			return 0, r.DisconnectSocket()
 		}
 		if r.length == 0 {
 			header := httpHeader(b[:nn])
 			r.length = header.ContentLength()
 		}
 		r.length -= int(nn)
 		if r.length == 0 {
 			return int(nn), r.DisconnectSocket()
 		}
 		n = int(nn)
 	case ConnectionTypeTLS:
 		nn, err := r.Rpc_wifi_get_ssl_receive(r.client, b, int32(len(b)))
 		if err != nil {
 			return 0, err
 		}
 		if nn < 0 {
 			return 0, fmt.Errorf("error %d", n)
 		} else if nn == 0 || nn == -30848 {
 			return 0, r.DisconnectSocket()
 		}
 		n = int(nn)
 	default:
 	}
 	return n, nil
 }
 func (r *RTL8720DN) IsSocketDataAvailable() bool {
 	if r.debug {
 		fmt.Printf("IsSocketDataAvailable()\r\n")
 	}
 	fmt.Printf("not implemented yet\r\n")
 	return true
 }
 func (r *RTL8720DN) Response(timeout int) ([]byte, error) {
 	if r.debug {
 		fmt.Printf("Response(%d))\r\n", timeout)
 	}
 	// No implementation required
 	return nil, nil
 }
@@ -0,0 +1,107 @@
 package rtl8720dn
 import (
 	"fmt"
 	"io"
 	"time"
 )
 var (
 	headerBuf            [4]byte
 	readBuf              [4]byte
 	startWriteMessageBuf [1024]byte
 	payload              [1024 + 256]byte
 )
 const (
 	xVersion = 1
 )
 func startWriteMessage(msgType, service, requestNumber, sequence uint32) []byte {
 	startWriteMessageBuf[0] = byte(msgType)
 	startWriteMessageBuf[1] = byte(requestNumber)
 	startWriteMessageBuf[2] = byte(service)
 	startWriteMessageBuf[3] = byte(xVersion)
 	startWriteMessageBuf[4] = byte(sequence)
 	startWriteMessageBuf[5] = byte(sequence >> 8)
 	startWriteMessageBuf[6] = byte(sequence >> 16)
 	startWriteMessageBuf[7] = byte(sequence >> 24)
 	return startWriteMessageBuf[:8]
 }
 func (r *RTL8720DN) performRequest(msg []byte) error {
 	crc := computeCRC16(msg)
 	headerBuf[0] = byte(len(msg))
 	headerBuf[1] = byte(len(msg) >> 8)
 	headerBuf[2] = byte(crc)
 	headerBuf[3] = byte(crc >> 8)
 	if r.debug {
 		fmt.Printf("tx : %2d : ", len(headerBuf))
 		dumpHex(headerBuf[:])
 		fmt.Printf("\r\n")
 	}
 	r.port.Write(headerBuf[:])
 	if r.debug {
 		fmt.Printf("tx : %2d : ", len(msg))
 		dumpHex(msg)
 		fmt.Printf("\r\n")
 	}
 	r.port.Write(msg)
 	return nil
 }
 func dumpHex(b []byte) {
 	for i := range b {
 		if i == 0 {
 			fmt.Printf("%02X", b[i])
 		} else {
 			fmt.Printf(" %02X", b[i])
 		}
 	}
 }
 func (r *RTL8720DN) readThread() {
 	for {
 		n, _ := io.ReadFull(r.port, readBuf[:4])
 		if n == 0 {
 			continue
 		}
 		if r.debug {
 			fmt.Printf("rx : %2d : ", n)
 			dumpHex(readBuf[:n])
 			fmt.Printf("\r\n")
 		}
 		length := uint16(readBuf[0]) + uint16(readBuf[1])<<8
 		crc := uint16(readBuf[2]) + uint16(readBuf[3])<<8
 		//fmt.Printf("len %d (%X) crc %04X\r\n", length, length, crc)
 		n, _ = io.ReadFull(r.port, payload[:length])
 		if r.debug {
 			fmt.Printf("rx : %2d : ", length)
 			dumpHex(payload[0:n])
 			fmt.Printf("\r\n")
 		}
 		n = int(length)
 		//fmt.Printf("rx : %2d : %s\n", n, dumpHex(payload[:n]))
 		crcNew := computeCRC16(payload[:n])
 		if g, e := crcNew, crc; g != e {
 			fmt.Printf("err CRC16: got %04X want %04X\n", g, e)
 		}
 		if payload[0] == 0x02 || payload[0] == 0x00 {
 			r.received <- true
 			// switch goroutine
 			time.Sleep(1)
 		}
 	}
 }
@@ -0,0 +1,54 @@
 package rtl8720dn
 import "io"
 type RTL8720DN struct {
 	port     io.ReadWriter
 	seq      uint64
 	received chan bool
 	debug    bool
 	connectionType ConnectionType
 	socket         int32
 	client         uint32
 	length         int
 	root_ca        *string
 }
 type ConnectionType int
 const (
 	ConnectionTypeNone ConnectionType = iota
 	ConnectionTypeTCP
 	ConnectionTypeUDP
 	ConnectionTypeTLS
 )
 func New(r io.ReadWriter) *RTL8720DN {
 	ret := &RTL8720DN{
 		port:     r,
 		seq:      1,
 		received: make(chan bool, 1),
 		debug:    false,
 	}
 	go ret.readThread()
 	return ret
 }
 func (r *RTL8720DN) SetSeq(s uint64) {
 	r.seq = s
 }
 func (r *RTL8720DN) Debug(b bool) {
 	r.debug = b
 }
 func (r *RTL8720DN) SetRootCA(s *string) {
 	r.root_ca = s
 }
 func (r *RTL8720DN) Version() (string, error) {
 	return r.Rpc_system_version()
 }
@@ -0,0 +1,37 @@
 package rtl8720dn
 // TODO: 後で整理する
 // https://github.com/Seeed-Studio/seeed-ambd-firmware/blob/master/erpc_idl/erpc_shim/rpc_system_header.h
 type RPC_T_GAP_CAUSE int32
 type RPC_T_LE_KEY_ENTRY int32
 type RPC_T_APP_RESULT int32
 type RPC_T_GAP_PARAM_TYPE int32
 type RPC_T_LE_BOND_PARAM_TYPE int32
 type RPC_T_GAP_CFM_CAUSE int32
 type RPC_T_GAP_REMOTE_ADDR_TYPE int32
 type RPC_T_GAP_SEC_LEVEL int32
 type RPC_T_GAP_LE_PARAM_TYPE int32
 type RPC_T_GAP_WHITE_LIST_OP int32
 type RPC_T_GAP_RAND_ADDR_TYPE int32
 type RPC_T_GAP_IDENT_ADDR_TYPE int32
 type RPC_T_GAP_CONFIG_GATT_CCCD_NOT_CHECK int32
 type RPC_T_LE_ADV_PARAM_TYPE int32
 type RPC_T_LE_SCAN_PARAM_TYPE int32
 type RPC_T_LE_CONN_PARAM_TYPE int32
 type RPC_T_GAP_CONN_INFO int32
 type RPC_T_GAP_PHYS_OPTIONS int32
 type RPC_T_GAP_CONN_PARAM_TYPE int32
 type RPC_T_GAP_LE_CONN_REQ_PARAM int32
 type RPC_T_GAP_LOCAL_ADDR_TYPE int32
 type RPC_T_LOCAL_NAME int32
 type RPC_T_LOCAL_APPEARANCE int32
 type RPC_T_LE_CCCD int32
 type RPC_T_LE_KEY_TYPE int32
 type RPC_T_GATT_WRITE_TYPE int32
 type RPC_T_GATT_PDU_TYPE int32
 type RPC_T_SERVICE_CALLBACK_TYPE int32
@@ -0,0 +1,51 @@
 package rtl8720dn
 import (
 	"bytes"
 	"encoding/binary"
 	"fmt"
 	"strconv"
 	"strings"
 )
 type httpHeader []byte
 func (h httpHeader) ContentLength() int {
 	contentLength := -1
 	idx := bytes.Index(h, []byte("Content-Length: "))
 	if 0 <= idx {
 		_, err := fmt.Sscanf(string(h[idx+16:]), "%d", &contentLength)
 		if err != nil {
 			return -1
 		}
 	}
 	return contentLength
 }
 // TODO: IPAddress implementation should be moved under drivers/net
 // The same implementation exists in wifinina.
 type IPAddress []byte
 func (addr IPAddress) String() string {
 	if len(addr) < 4 {
 		return ""
 	}
 	return strconv.Itoa(int(addr[0])) + "." + strconv.Itoa(int(addr[1])) + "." + strconv.Itoa(int(addr[2])) + "." + strconv.Itoa(int(addr[3]))
 }
 func ParseIPv4(s string) (IPAddress, error) {
 	v := strings.Split(s, ".")
 	v0, _ := strconv.Atoi(v[0])
 	v1, _ := strconv.Atoi(v[1])
 	v2, _ := strconv.Atoi(v[2])
 	v3, _ := strconv.Atoi(v[3])
 	return IPAddress([]byte{byte(v0), byte(v1), byte(v2), byte(v3)}), nil
 }
 func (addr IPAddress) AsUint32() uint32 {
 	if len(addr) < 4 {
 		return 0
 	}
 	b := []byte(string(addr))
 	return binary.BigEndian.Uint32(b[0:4])
 }
@@ -0,0 +1,72 @@
 package rtl8720dn
 import (
 	"fmt"
 	"time"
 )
 func (r *RTL8720DN) ConnectToAP(ssid string, password string) error {
 	if len(ssid) == 0 || len(password) == 0 {
 		return fmt.Errorf("connection failed: either ssid or password not set")
 	}
 	_, err := r.Rpc_wifi_off()
 	if err != nil {
 		return err
 	}
 	_, err = r.Rpc_wifi_on(0x00000001)
 	if err != nil {
 		return err
 	}
 	_, err = r.Rpc_wifi_disconnect()
 	if err != nil {
 		return err
 	}
 	numTry := 5
 	securityType := uint32(0x00400004)
 	for i := 0; i < numTry; i++ {
 		ret, err := r.Rpc_wifi_connect(ssid, password, securityType, -1, 0)
 		if err != nil {
 			return err
 		}
 		if ret != 0 {
 			if i == numTry-1 {
 				return fmt.Errorf("connection failed: rpc_wifi_connect failed")
 			}
 			time.Sleep(100 * time.Millisecond)
 		} else {
 			break
 		}
 	}
 	_, err = r.Rpc_tcpip_adapter_dhcpc_start(0)
 	if err != nil {
 		return err
 	}
 	for i := 0; i < 3; i++ {
 		_, err = r.Rpc_wifi_is_connected_to_ap()
 		if err != nil {
 			return err
 		}
 		time.Sleep(1 * time.Second)
 	}
 	return nil
 }
 func (r *RTL8720DN) GetIP() (ip, subnet, gateway IPAddress, err error) {
 	ip_info := make([]byte, 12)
 	_, err = r.Rpc_tcpip_adapter_get_ip_info(0, ip_info)
 	if err != nil {
 		return nil, nil, nil, err
 	}
 	ip = IPAddress(ip_info[0:4])
 	subnet = IPAddress(ip_info[4:8])
 	gateway = IPAddress(ip_info[8:12])
 	return ip, subnet, gateway, nil
 }