Add network device driver model, netdev

examples/net/mqttclient/main.go

@@ -0,0 +1,100 @@
+// This example is a MQTT client.  It sends machine.ReadTemparature() readings
+// to the broker every second for 10 seconds.
+//
+// Note: It may be necessary to increase the stack size when using
+// paho.mqtt.golang.  Use the -stack-size=4KB command line option.
+
+package main
+
+import (
+	"fmt"
+	"log"
+	"machine"
+	"math/rand"
+	"time"
+
+	mqtt "github.com/eclipse/paho.mqtt.golang"
+)
+
+var (
+	ssid   string
+	pass   string
+	broker string = "tcp://test.mosquitto.org:1883"
+)
+
+var messagePubHandler mqtt.MessageHandler = func(client mqtt.Client, msg mqtt.Message) {
+	fmt.Printf("Message %s received on topic %s\n", msg.Payload(), msg.Topic())
+}
+
+var connectHandler mqtt.OnConnectHandler = func(client mqtt.Client) {
+	fmt.Println("Connected")
+}
+
+var connectionLostHandler mqtt.ConnectionLostHandler = func(client mqtt.Client, err error) {
+	fmt.Printf("Connection Lost: %s\n", err.Error())
+}
+
+func main() {
+	waitSerial()
+
+	if err := netdev.NetConnect(); err != nil {
+		log.Fatal(err)
+	}
+
+	clientId := "tinygo-client-" + randomString(10)
+	fmt.Printf("ClientId: %s\n", clientId)
+
+	options := mqtt.NewClientOptions()
+	options.AddBroker(broker)
+	options.SetClientID(clientId)
+	options.SetDefaultPublishHandler(messagePubHandler)
+	options.OnConnect = connectHandler
+	options.OnConnectionLost = connectionLostHandler
+
+	fmt.Printf("Connecting to MQTT broker at %s\n", broker)
+	client := mqtt.NewClient(options)
+	token := client.Connect()
+	if token.Wait() && token.Error() != nil {
+		panic(token.Error())
+	}
+
+	topic := "cpu/freq"
+	token = client.Subscribe(topic, 1, nil)
+	if token.Wait() && token.Error() != nil {
+		panic(token.Error())
+	}
+	fmt.Printf("Subscribed to topic %s\n", topic)
+
+	for i := 0; i < 10; i++ {
+		freq := float32(machine.CPUFrequency()) / 1000000
+		payload := fmt.Sprintf("%.02fMhz", freq)
+		token = client.Publish(topic, 0, false, payload)
+		if token.Wait() && token.Error() != nil {
+			panic(token.Error())
+		}
+		time.Sleep(time.Second)
+	}
+
+	client.Disconnect(100)
+}
+
+// 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)
+}
+
+// Wait for user to open serial console
+func waitSerial() {
+	for !machine.Serial.DTR() {
+		time.Sleep(100 * time.Millisecond)
+	}
+}