espat: some improvements for response handling

Signed-off-by: deadprogram <ron@hybridgroup.com>

espat/adapter.go

@@ -11,7 +11,10 @@ func (d *Device) ConnectToAccessPoint(ssid, pass string, timeout time.Duration)
 		return net.ErrWiFiMissingSSID
 	}
 
-	d.SetWifiMode(WifiModeClient)
+	if err := d.SetWifiMode(WifiModeClient); err != nil {
+		return err
+	}
+
 	return d.ConnectToAP(ssid, pass, 10)
 }
 

espat/espat.go

@@ -152,17 +152,17 @@ func (d *Device) ReadSocket(b []byte) (n int, err error) {
 // The call will retry for up to timeout milliseconds before returning nothing.
 func (d *Device) Response(timeout int) ([]byte, error) {
 	// read data
-	var size int
 	var start, end int
-	pause := 100 // pause to wait for 100 ms
-	retries := timeout / pause
+	pause := 10 * time.Millisecond
+	starting := time.Now()
 
 	for {
-		size = d.bus.Buffered()
-
-		if size > 0 {
+		if size := d.bus.Buffered(); size > 0 {
 			end += size
-			d.bus.Read(d.response[start:end])
+			_, err := d.bus.Read(d.response[start:end])
+			if err != nil {
+				return nil, err
+			}
 
 			// if "+IPD" then read socket data
 			if strings.Contains(string(d.response[:end]), "+IPD") {
@@ -185,12 +185,11 @@ func (d *Device) Response(timeout int) ([]byte, error) {
 		}
 
 		// wait longer?
-		retries--
-		if retries == 0 {
+		if time.Since(starting) > time.Duration(timeout)*time.Millisecond {
 			return nil, errors.New("response timeout error:" + string(d.response[start:end]))
 		}
 
-		time.Sleep(time.Duration(pause) * time.Millisecond)
+		time.Sleep(pause)
 	}
 }
 

espat/tcp.go

@@ -36,7 +36,7 @@ func (d *Device) GetDNS(domain string) (string, error) {
 // Currently only supports single connection mode.
 func (d *Device) ConnectTCPSocket(addr, port string) error {
 	protocol := "TCP"
-	val := "\"" + protocol + "\",\"" + addr + "\"," + port + ",120"
+	val := "\"" + protocol + "\"," + addr + "," + port + ",120"
 	err := d.Set(TCPConnect, val)
 	if err != nil {
 		return err
@@ -51,7 +51,7 @@ func (d *Device) ConnectTCPSocket(addr, port string) error {
 // ConnectUDPSocket creates a new UDP connection for the ESP8266/ESP32.
 func (d *Device) ConnectUDPSocket(addr, sendport, listenport string) error {
 	protocol := "UDP"
-	val := "\"" + protocol + "\",\"" + addr + "\"," + sendport + "," + listenport + ",2"
+	val := "\"" + protocol + "\"," + addr + "," + sendport + "," + listenport + ",2"
 	err := d.Set(TCPConnect, val)
 	if err != nil {
 		return err
@@ -67,7 +67,7 @@ func (d *Device) ConnectUDPSocket(addr, sendport, listenport string) error {
 // Currently only supports single connection mode.
 func (d *Device) ConnectSSLSocket(addr, port string) error {
 	protocol := "SSL"
-	val := "\"" + protocol + "\",\"" + addr + "\"," + port + ",120"
+	val := "\"" + protocol + "\"," + addr + "," + port + ",120"
 	d.Set(TCPConnect, val)
 	// this operation takes longer, so wait up to 6 seconds to complete.
 	_, err := d.Response(6000)
@@ -123,7 +123,10 @@ func (d *Device) GetTCPTransferMode() ([]byte, error) {
 // StartSocketSend gets the ESP8266/ESP32 ready to receive TCP/UDP socket data.
 func (d *Device) StartSocketSend(size int) error {
 	val := strconv.Itoa(size)
-	d.Set(TCPSend, val)
+	err := d.Set(TCPSend, val)
+	if err != nil {
+		return err
+	}
 
 	// when ">" is received, it indicates
 	// ready to receive data