rtl8720dn: add examples/rtl8720dn/mqtt*

examples/rtl8720dn/mqttclient/main.go

@@ -0,0 +1,131 @@
+// This is a sensor station that uses a RTL8720DN running on the device UART2.
+// It creates an MQTT connection that publishes a message every second
+// to an MQTT broker.
+//
+// In other words:
+// Your computer <--> USB-CDC <--> MCU <--> UART2 <--> RTL8720DN <--> Internet <--> MQTT broker.
+//
+// You must install the Paho MQTT package to build this program:
+//
+// 		go get -u github.com/eclipse/paho.mqtt.golang
+//
+// You can check that mqttpub is running successfully with the following command.
+//
+// 		mosquitto_sub -h test.mosquitto.org -t tinygo
+//
+package main
+
+import (
+	"fmt"
+	"math/rand"
+	"time"
+
+	"tinygo.org/x/drivers/net"
+	"tinygo.org/x/drivers/net/mqtt"
+	"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 = "tcp://test.mosquitto.org:1883"
+	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)
+	}
+}
+
+var (
+	topic = "tinygo"
+)
+
+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)
+
+	rand.Seed(time.Now().UnixNano())
+
+	opts := mqtt.NewClientOptions()
+	opts.AddBroker(server).SetClientID("tinygo-client-" + randomString(10))
+
+	println("Connectng to MQTT...")
+	cl := mqtt.NewClient(opts)
+	if token := cl.Connect(); token.Wait() && token.Error() != nil {
+		failMessage(token.Error().Error())
+	}
+
+	for i := 0; ; i++ {
+		println("Publishing MQTT message...")
+		data := []byte(fmt.Sprintf(`{"e":[{"n":"hello %d","v":101}]}`, i))
+		token := cl.Publish(topic, 0, false, data)
+		token.Wait()
+		if err := token.Error(); err != nil {
+			return err
+		}
+		time.Sleep(100 * time.Millisecond)
+	}
+
+	// Right now this code is never reached. Need a way to trigger it...
+	println("Disconnecting MQTT...")
+	cl.Disconnect(100)
+
+	println("Done.")
+
+	return nil
+}
+
+// Returns an int >= min, < max
+func randomInt(min, max int) int {
+	return min + rand.Intn(max-min)
+}
+
+// Generate a random string of A-Z chars with len = l
+func randomString(len int) string {
+	bytes := make([]byte, len)
+	for i := 0; i < len; i++ {
+		bytes[i] = byte(randomInt(65, 90))
+	}
+	return string(bytes)
+}
+
+func failMessage(msg string) {
+	for {
+		println(msg)
+		time.Sleep(1 * time.Second)
+	}
+}