B4R Question HTTP request using GSM SIM800/900

[pokhraj_d]

Hello All,
Here I have shown how we can use b4r to send http request to any cloud server using gsm SIM800 or gsm SIM900.

We need to add GSM.bas and Globalstore.bas to add to the current project by using Project->Add existing module.

You can also add timer or addLooper to send http request every 1 sec.

Please note I am using GET method to send the request to cloud server.

Sub Process_Globals
    Private serial As SoftwareSerial
    Private bc As ByteConverter
    Private astream As AsyncStreams
    Private EOL() As Byte = Array As Byte(13, 10)
    Private busy As Boolean
    Private state As Int
    Private ServerResponse As Boolean
End Sub

Public Sub Init(rx As Byte, tx As Byte)
    serial.Initialize(9600, rx, tx)
    astream.Initialize(serial.Stream, "astream_NewData", Null)
    astream.WaitForMoreDataDelay = 100 'make sure that we receive full messages
    busy = False
End Sub

Public Sub getHumid(humid() As Byte)
    GlobalStore.Put(0,humid)
End Sub

private Sub checkResult(buffer() As Byte, cmdstatus As Boolean)
    'Select True
    If bc.IndexOf(buffer,"AT+CPIN?") > -1 And bc.IndexOf(buffer,"+CPIN: READY") > -1 And bc.IndexOf(buffer,"OK") > -1 Then
            cmdstatus=True
            Log("==>Command Success!!")
        End If
        If bc.IndexOf(buffer, "+CREG: 0,1") > -1 Or bc.IndexOf(buffer, "+CREG: 0,5") > -1 Then
            cmdstatus=True
           Log("==>Command Success!!")
        End If
       If bc.IndexOf(buffer, "AT+CGATT?") > -1 And bc.IndexOf(buffer,"+CGATT: 0") > -1 Then
            Log("GPRS not attached!!")
            cmdstatus=True
        End If
            If bc.IndexOf(buffer, "AT+CGATT?") > -1 And bc.IndexOf(buffer,"+CGATT: 1") > -1 Then
                Log("==>Command Success!!")
                Log("==>GPRS Attached!!")
                cmdstatus=True
            End If
            If bc.IndexOf(buffer,"AT+SAPBR=3,1") > -1 And bc.IndexOf(buffer,"OK") > -1 Then
                cmdstatus=True
               Log("==>Command Success!!")
            End If
            'Set the APN Status
        If bc.IndexOf(buffer,"APN") > -1 And bc.IndexOf(buffer, "OK") > -1 Then
            cmdstatus=True
           Log("==>Command Success!!")
        End If
        'Enable GPRS Status
        If bc.IndexOf(buffer, "AT+SAPBR =1,1") > 1 And bc.IndexOf(buffer, "OK") > -1 Then
               cmdstatus=True
               Log("==>Command Success!!")
        End If
            If bc.IndexOf(buffer, "AT+SAPBR=2,1") > -1 And bc.IndexOf(buffer, "+SAPBR: 1,1") > -1 Then
                cmdstatus=True
                Log("==>Command Success!!")
            End If
            If bc.IndexOf(buffer,"AT+HTTPINIT") > -1 And bc.IndexOf(buffer,"OK") > -1 Then
                    cmdstatus=True
                    Log("==>Command Success!!")
            End If
End Sub


Public Sub Start
    state = 1
    ServerResponse = False
    Connect
End Sub

Private Sub Connect
    Log("Connect State: ", state)
    Select state
        Case 1
            astream.Write("AT+CPIN?").Write(EOL)  'Check for SIM Status
        Case 2
            astream.Write("AT+CREG?").Write(EOL)  'Check for SIM registered status
        Case 3
            astream.Write("AT+CGATT?").Write(EOL)  'Check for GPRS status
        Case 4  'Set connection type as GPRS
            astream.Write("AT+SAPBR=3,1").Write(",""").Write("contype").Write(""",""").Write("GPRS").Write("""").Write(EOL)
        Case 5 'Set the APN
            astream.Write("AT+SAPBR=3,1").Write(",""").Write("APN").Write(""",""").Write("airtelgprs.com").Write("""").Write(EOL)
        Case 6
            astream.Write("AT+SAPBR=2,1").Write(EOL) 'Check to see the GPRS is enabled and IP has been allocated
        Case 7
            astream.Write("AT+HTTPINIT").Write(EOL) 'Enable HTTP Mode
        Case 8
            astream.Write("AT+HTTPPARA=""CID"",1").Write(EOL) ''Carrer Identifier
        Case 9
            astream.Write("AT+HTTPPARA=""URL"",""http://xxxxx.com/abc.php?humid").Write("=").Write(GlobalStore.Slot0).Write("""").Write(EOL)
        Case 10
            astream.Write("AT+HTTPPARA=""CONTENT"",""application/json""").Write(EOL) ''Carrer Identifier
        Case 11
            astream.Write("AT+HTTPDATA=5,5000").Write(EOL) 'Send the data 5 is no of byte and 5000 is millis
        Case 12
            astream.Write("Delay=6000").Write(EOL)
        Case 13
            astream.Write("AT+HTTPACTION=0").Write(EOL) '0 is for GET and 1 is for POST
     
    End Select
End Sub



Sub AStream_NewData (Buffer() As Byte)
    'Log("****************")
    Log(Buffer)
    checkResult(Buffer,True)
    If ServerResponse Then Return
    busy = False
            If  state < 13 Then
                state = state + 1
                Connect
            End If
End Sub

Below is my APP Module:

Sub Process_Globals
    'These global variables will be declared once when the application starts.
    'Public variables can be accessed from all modules.
    Public Serial1 As Serial
    Private humid As String = "77.77"  'Hardcoded for testing purpose
End Sub

Private Sub AppStart
    Serial1.Initialize(115200)
    Log("AppStart")
    GSM.Init(10,12)
    GSM.Start
    GSM.getHumid(humid)
End Sub

 

[tigrot]

Don't be so fast in repeating get's every each second. Every successive request could cancel previous if request is not timed out.