How to display a byte other than its ASCII?

[zhengsimon]

Hi,

I read parameters from my ECU thru RS232 and display them on TextBox. But the display is ASCII instead of itself. E.g. I read 0x01 and store it in DataReceived, and set

Dim DataRecevied As Byte

TextBox1.Text = DataReceived

The value appeared in TextBox1 is 49 (0x31), which is ASCII of 0x01. How to display 01 there?

Thanks,

[kleinma]

Are you sure the value you are getting from the RS232 is 0x01?

If you just try this simple code, you will see setting a textbox.text value, to a byte that contains 0x01 does in fact show 1 in the textbox, not 49

        Dim DataRecevied As Byte = &H1
        TextBox1.Text = DataRecevied

in VB, 0x01 is wrtten as &H1

[zhengsimon]

Are you sure the value you are getting from the RS232 is 0x01?

If you just try this simple code, you will see setting a textbox.text value, to a byte that contains 0x01 does in fact show 1 in the textbox, not 49

        Dim DataRecevied As Byte = &H1
        TextBox1.Text = DataRecevied

in VB, 0x01 is wrtten as &H1

Thanks. But I got the same issue as before. BTW how to set if the variable is an array DataReceived(11,4)?

[kleinma]

You mean if you run my code, you get 49 in the textbox?

[zhengsimon]

You mean if you run my code, you get 49 in the textbox?

Yes. The simple test was to use DecimalValue(0, 0) declared as Short. I typed 1 in TextBox1 and store it to DecimalVlaue(0,0) as follows. Then I sent it using SerialPort.Write().

DecimalValue(0, 0) = Convert.ToInt16(TextBox1.Text)
SerialPort.Write(DecimalValue(0, 0))

By shorting Rx and Tx of RS232, I got the value I sent out and store it as follows :

DataReceived(0, 0) = Convert.ToByte(buffer(0))
TextBox1.Text = DataReceived(0, 0)

Because the code you told didn't work for array. I changed my code without array. It still show 49 other than 1 in textbox.

[dbasnett]

        Dim buff() As Byte = New Byte() {1}
        SerialPort1.Write(buff, 0, 1)



    Private Sub SerialPort1_DataReceived(ByVal sender As Object, ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) Handles SerialPort1.DataReceived
        Dim numBytes As Integer = SerialPort1.BytesToRead 'get number of bytes to read
        Dim buff() As Byte = New Byte(numBytes - 1) {} 'create a buffer
        numBytes = SerialPort1.Read(buff, 0, numBytes) 'read available bytes
        For x As Integer = 0 To buff.Length - 1 'show bytes read as hex
            Debug.WriteLine(buff(x).ToString("X")) 'show as hex
        Next
    End Sub

[Shaggy Hiker]

That doesn't sound like what Kleinma suggested. You say you typed 1 in a textbox, but he set 1 to a variable. You are seeing the ascii for the text character "1", not the numeral 1 converted to a string.

put a breakpoint on the write, and take a look at what is in DecimalValue(0,0). It should be 1.

By the way, SerialPort.Write has only one version that takes a single argument, and that argument is a string. I would say that the code is implicitly converting DecimalValue(0,0) to a string and sending that, rather than sending the value. This would only be possible if you have Option Strict Off. Turn Option Strict ON, deal with the errors that arise, and this problem will have been clarified.

[Shaggy Hiker]

I figured I'd be a bit slow, and I was wondering where dbasnett was, since this was a serial issue. However, he did the same thing Kleinma did, which is write a byte rather than a string.

[dbasnett]

serialport write has three methods.

[kleinma]

I would suggest turning option strict on, which will probably force more explict accurate conversions of the datatypes, instead of hoping the runtime converts them to what you want.

[dbasnett]

I would suggest turning option strict on, which will probably force more explict accurate conversions of the datatypes, instead of hoping the runtime converts them to what you want.

amen to that!

[zhengsimon]

        Dim buff() As Byte = New Byte() {1}
        SerialPort1.Write(buff, 0, 1)



    Private Sub SerialPort1_DataReceived(ByVal sender As Object, ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) Handles SerialPort1.DataReceived
        Dim numBytes As Integer = SerialPort1.BytesToRead 'get number of bytes to read
        Dim buff() As Byte = New Byte(numBytes - 1) {} 'create a buffer
        numBytes = SerialPort1.Read(buff, 0, numBytes) 'read available bytes
        For x As Integer = 0 To buff.Length - 1 'show bytes read as hex
            Debug.WriteLine(buff(x).ToString("X")) 'show as hex
        Next
    End Sub

Thanks. It does show its hex value but is ASCII hex. E.g. if I send 1, it shows 31. For one digit, I can convert it by minus 0x30. However for two digits it only shows the first one. E.g. if I type 21, it shows 32 (ASCII Hex value of the 1st digit 2).

Any other solutions?

I appreciate it!

[Shaggy Hiker]

If you are just sending things that have been typed into a textbox, then they are strings, so leave them as strings. Once they have been transmitted, then you can take the string and convert in to an integer with Integer.TryParse or something like that. Right now, you seem to be fighting to get a string (which happens to represent a number, but is still just a string, since it comes from a textbox) into some other form prior to transmission. Leave the conversion until afterwards.

[dbasnett]

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        'i have the port open and a loop back
        Debug.WriteLine("")
        Dim buff() As Byte = New Byte() {0}
        For x As Integer = 1 To 16
            buff(0) = CByte(x)
            SerialPort1.Write(buff, 0, 1)
        Next x
    End Sub
    Private Sub SerialPort1_DataReceived(ByVal sender As Object, ByVal e As System.IO.Ports.SerialDataReceivedEventArgs) Handles SerialPort1.DataReceived
        Dim numBytes As Integer = SerialPort1.BytesToRead 'get number of bytes to read
        Dim buff() As Byte = New Byte(numBytes - 1) {} 'create a buffer
        numBytes = SerialPort1.Read(buff, 0, numBytes) 'read available bytes
        For x As Integer = 0 To buff.Length - 1 'show bytes read as hex
            'when button 1 is clicked the debug output is
            '0102030405060708090A0B0C0D0E0F10
            'from the statement that follows
            Debug.Write(buff(x).ToString("X").PadLeft(2, "0"c)) 'show as hex
            ' looks like hex to me
        Next
    End Sub

[zhengsimon]

I appreciate everybody's help! It works now.

[dbasnett]

mark thread resolved (under Thread Tools) and if you want rate posters that helped.