Thread: Why the data sent is double?

.......Hello there..i encountered one problem when sending this message...that is when i am sending the
putrsUSART("ok");
over to my hyperterminal from my PICDEM 2 PLUS BOARD in MPLAB ICD 2,the data that i received is ok[00].do you know how to get it send only ok?and when i the second data is send the hyperterminal will be seeing ok[00]ok[00]..and the data keep echoing following the number of ok sent..here i attached on the code for you to have a look.so hope you can help....

#include <p18f452.h>
#include <usart.h>
#include <delays.h>

char getcharusart()
{
// Wait until the byte recieved interrupt flag (RCIF) is set on the interrupt register
while (!PIR1bits.RCIF)
continue;

//Clear the interrupt register until another byte is recieved
PIR1bits.RCIF = 0;

//Return the value stored in RCREG, which is the byte that has been recieved
return RCREG;
}


void main(void)
{
//port configuration
TRISCbits.TRISC6 = 0;
TRISCbits.TRISC7 = 1;

// configure USART
OpenUSART( USART_TX_INT_OFF &
USART_RX_INT_OFF & //usart configuration
USART_ASYNCH_MODE &
USART_EIGHT_BIT &
USART_CONT_RX &
USART_BRGH_HIGH,25 );



//All PORTB are outputs
TRISB = 0;

//Clear PORTB
PORTB = 0;

// while (1)
{
//PORTB =getcharusart();
putrsUSART("ok"); //9600,n,8,1!\r\n");

}


}

Without knowing what those two things are and how they work, we can't help. It looks like the bracketed number might be the number of errors encountered on the last burst or something.

Originally Posted by ooicheesan

putrsUSART("ok");

Meaning:
"ok" = {'o','k',0};-> zero, the terminating string's char.
To send ok, the final 0 seems to be sent also.

The data that i sent from my board to the VB at comm 1 is double..the char that i am sending out form my board is to clear the timer of my VB as acknowledgement that the byte is received by the board..so since it is quite troublesome to saying how it work...i attached on the Vb code for you to have a look so that you to have a look at my serial communication... hope to hear from you soon..


'Data Declaration required
Option Explicit
'Declare data as global attributes
Dim byteDataA As Byte
Dim byteDataB As Byte
Dim byteDataC As Byte
Dim sLastSend As String
Dim bTimerCount As Byte

Private Sub Check1_Click(Index As Integer)
'Private data declaration
Dim temp As Byte


If Check1(Index).Value = 1 Then
'Byte Calulation by Or operation
temp = 2 ^ Index
byteDataA = byteDataA Or temp
Else
'Byte Calculation by Xor and And operation
temp = 255 Xor 2 ^ Index
byteDataA = byteDataA And temp

End If
'Send data to MSComm port
Send_Inform "A" & Chr(byteDataA)

End Sub

Private Sub Check2_Click(Index As Integer)
Dim temp As Byte

If Check2(Index).Value = 1 Then
'Byte Calulation by Or operation
temp = 2 ^ Index
byteDataB = byteDataB Or temp

Else
'Byte Calulation by Xor and And operation
temp = 255 Xor 2 ^ Index
byteDataB = byteDataB And temp

End If
'Send data to MSComm port
Send_Inform "B" & Chr(byteDataB)

End Sub

Private Sub Check3_Click(Index As Integer)
Dim temp As Byte


If Check3(Index).Value = 1 Then
'Byte Calulation by Or operation
temp = 2 ^ Index
byteDataC = byteDataC Or temp

Else
'Byte Calulation by Xor and And operation
temp = 255 Xor 2 ^ Index
byteDataC = byteDataC And temp

End If
'Send data to MSComm port
Send_Inform "C" & Chr(byteDataC)

End Sub


Public Sub Send_Inform(sMsg As String)
'Marked last sent message
sLastSend = sMsg
'MSComm output last send Msg
MSComm1.Output = sLastSend
'Activate timer
tmrResponse.Enabled = True

End Sub



Private Sub tmrResponse_Timer()
'Initialize timer to "0"
tmrResponse.Enabled = False

'Check byte timer count
If bTimerCount < 2 Then
'Send last sent Msg
Send_Inform sLastSend
bTimerCount = bTimerCount + 1

Else
'Indicate that no reply from hardware after 5000ms
MsgBox "No responce from the hardware."
'Reset counter
bTimerCount = 0


End If


End Sub


Private Sub Form_Load()

With MSComm1
'Activate the MSComm port
If .PortOpen = True Then .PortOpen = False
'Selecting MSComm Port 1
.CommPort = 1
'9600 Baud, No Parity, 8 Data Bits, 1 Stop Bit
.Settings = "9600,n,8,1"
'Enable port 1
.PortOpen = True
End With

End Sub
Private Sub MSComm1_OnComm()
Dim sTemp As String
'Enabling MSComm to receive MSg
Select Case MSComm1.CommEvent
'COmm Recieve Event
Case comEvReceive
'Receive Data at MSComm Port 1
sTemp = MSComm1.Input
'Check for "ok"
If sTemp = "ok" Then
'If "ok" detected reset Timer count
tmrResponse.Enabled = False
bTimerCount = 0

End If


End Select
End Sub