rtl8720dn: add examples/rtl8720dn/mqtt*

rtl8720dn/rtl8720dn.go

@@ -3,10 +3,10 @@ package rtl8720dn
 import "io"
 
 type RTL8720DN struct {
-	port     io.ReadWriter
-	seq      uint64
-	received chan bool
-	debug    bool
+	port  io.ReadWriter
+	seq   uint64
+	sema  chan bool
+	debug bool
 
 	connectionType ConnectionType
 	socket         int32
@@ -26,14 +26,12 @@ const (
 
 func New(r io.ReadWriter) *RTL8720DN {
 	ret := &RTL8720DN{
-		port:     r,
-		seq:      1,
-		received: make(chan bool, 1),
-		debug:    false,
+		port:  r,
+		seq:   1,
+		sema:  make(chan bool, 1),
+		debug: false,
 	}
 
-	go ret.readThread()
-
 	return ret
 }