B4R Question android send udp packet to esp8266, error occured.

[tzfpg]

Hi all,
After connect to esp8266, and send udp packet, android often occured error and esp8266 can't receive the packet.

error code:

Phone WifiIpAddress 192.168.4.3
java.io.IOException: sendto failed: ENETUNREACH (Network is unreachable)
    at libcore.io.IoBridge.maybeThrowAfterSendto(IoBridge.java:576)
    at libcore.io.IoBridge.sendto(IoBridge.java:544)
    at java.net.PlainDatagramSocketImpl.send(PlainDatagramSocketImpl.java:125)
    at java.net.DatagramSocket.send(DatagramSocket.java:721)
    at anywheresoftware.b4a.objects.SocketWrapper$UDPSocket$1.run(SocketWrapper.java:479)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:458)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641)
    at java.lang.Thread.run(Thread.java:764)
Caused by: android.system.ErrnoException: sendto failed: ENETUNREACH (Network is unreachable)
    at libcore.io.Linux.sendtoBytes(Native Method)
    at libcore.io.Linux.sendto(Linux.java:227)
    at libcore.io.BlockGuardOs.sendto(BlockGuardOs.java:307)
    at libcore.io.IoBridge.sendto(IoBridge.java:542)
    ... 8 more

android code:

btn_Click
    Dim b1(2) As Object
    b1(0) = "test"
    b1(1) = "1"
    UDP_Send(Starter.ser.ConvertArrayToBytes(b1))
End Sub

Sub UDP_Send(data() As Byte)
    udp_start
    Dim Packet As UDPPacket
    Packet.Initialize(data, udp_ip, 8888)
    usocket.Send(Packet)
End Sub

Sub udp_start
    Dim ip_str() As String = Regex.Split("\.", Main.wifi.WifiIpAddress)
    If ip_str(0) = "192" And ip_str(1) = "168" And ip_str(2) = "4" Then
        If usocket.IsInitialized = False Then
            usocket.Initialize("UDP", 8888, 1024)
        End If
    End If
End Sub

android send packet very not stable, how can solve this error?

Thank you.

 

[Erel]

Based on the error message the Android device wasn't connected to the network.

 

[tzfpg]

i found the problem is android device connect to esp8266 no more than 4 second, then disconnect.
how to connect esp8266 wifi more then 5 second?

 

[Erel]

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