B4R Tutorial Downloading a Web page with ESP8266

Discussion in 'B4R Tutorials' started by Erel, Sep 1, 2016.

  1. Erel

    Erel Administrator Staff Member Licensed User

    Edit: use rHttpUtils2 instead: https://www.b4x.com/android/forum/threads/module-rhttputils2-http-client.74785/#content
    As a general rule, I recommend to use Raspberry Pi with B4J to interact with web servers or http clients. It is much more powerful and simpler to develop. The Arduino and ESP8266 strengths are in other domains.

    This small example sends a http request with WiFiSocket and reads the response with AsyncStreams.

    Sub Process_Globals
    Public Serial1 As Serial
    Private wifi As ESP8266WiFi
    Private astream As AsyncStreams
    Private socket As WiFiSocket
    End Sub

    Private Sub AppStart
    If wifi.Connect("dlink"Then 'change as needed
         Log("Connected to router")
    Log("Failed to connect")
    End If
    End Sub

    Sub Connect(unused As Byte)
    If socket.ConnectHost("example.com"80) = False Then
    Log("trying to connect again")
    End If
    Log("Connected to server")
    socket.Stream, "Astream_NewData""Astream_Error")
    Dim eol() As Byte = Array As Byte(1310)
    "GET / HTTP/1.1".GetBytes)
    "Host: www.example.com".GetBytes)
    "Connection: close".GetBytes)
    End Sub

    Sub Astream_NewData (Buffer() As Byte)
    End Sub

    Sub Astream_Error
    End Sub
    The html page will be printed to the logs.

    This code depends on the following libraries:
    rESP8266, rESP8266WiFi and rRandomAccessFile.
    Last edited: Dec 21, 2017
  2. John Decowski

    John Decowski Member Licensed User

    I try to download simple website hosted by my own iis server and returns http error 400 bad request invalid verb

    Any ideas?
  3. Erel

    Erel Administrator Staff Member Licensed User

    You should use rHttpUtils2 instead of this code.
    John Decowski likes this.
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