Zebra Printer Outputing HEX when trying to print a bitmap - vb.net

Question

I am using a Zebra iMZ320 printer, a windows mobile device, CPCL and vb.net.
I am trying to get the code to load a bitmap image and then to print this using CPCL
I have previoulsy had a similar piece of code to that contaibed below working with no issue. I must be missing something obvious, but for the life of me I cannot see it.
My problem is the printer will only printout HEX instead of the image ! Has anyone come across this before ? Can you help ?
Public Sub DrawBitmap(ByVal xPosition As Integer, ByVal yPosition As Integer)
Dim bmp As Bitmap
bmp = New System.Drawing.Bitmap(GetLogo)
If bmp Is Nothing Then
Throw New ArgumentNullException("bmp")
End If
'Make sure the width is divisible by 8
Dim loopWidth As Integer = 8 - (bmp.Width Mod 8)
If loopWidth = 8 Then
loopWidth = bmp.Width
Else
loopWidth += bmp.Width
End If
cpclData = ""
cpclData = cpclData & "! 0 200 200 300 1 " & vbCr & vbLf
cpclData = cpclData & (String.Format("EG {0} {1} {2} {3} ", loopWidth \ 8, bmp.Height, xPosition, yPosition))
For y As Integer = 0 To bmp.Height - 1
Dim bit As Integer = 128
Dim currentValue As Integer = 0
For x As Integer = 0 To loopWidth - 1
Dim intensity As Integer
If x < bmp.Width Then
Dim color As Color = bmp.GetPixel(x, y)
Dim MyR As Integer = color.R
Dim MyG As Integer = color.G
Dim MyB As Integer = color.B
intensity = 255 - ((MyR + MyG + MyB) / 3)
Else
intensity = 0
End If
If intensity >= 128 Then
currentValue = currentValue Or bit
End If
bit = bit >> 1
If bit = 0 Then
cpclData = cpclData & (currentValue.ToString("X2"))
bit = 128
currentValue = 0
End If
'x
Next
Next
'y
cpclData = cpclData & vbCr & vbLf
cpclData = cpclData & "PRINT"
Print_Invoice()
End Sub
Public Shared Function StrToByteArray(ByVal str As String) As Byte()
Dim encoding As New System.Text.ASCIIEncoding()
Return encoding.GetBytes(str)
End Function
Private Sub Print_Invoice()
' Instantiate a connection
Dim thePrinterConn As ZebraPrinterConnection = New BluetoothPrinterConnection(MyMacAddress)
' Open the connection - physical connection is established here.
thePrinterConn.Open()
' Send the data to the printer as a byte array
thePrinterConn.Write(StrToByteArray(cpclData))
' Make sure the data got to the printer before closing the connection
Thread.Sleep(500)
' Close the connection to release resources.
thePrinterConn.Close()
' Debug output
txt_TestPrint.Text = cpclData.ToString
Dim objStreamWriter As StreamWriter
Dim file_name As String
'open dialog box for new file
SaveFileDialog1.InitialDirectory = "\Storage Card\"
If SaveFileDialog1.ShowDialog() = Windows.Forms.DialogResult.OK Then
file_name = SaveFileDialog1.FileName
If Len(file_name) > 0 Then
objStreamWriter = New StreamWriter(file_name & ".txt")
'Write a line of text from list box.
objStreamWriter.WriteLine(txt_TestPrint.Text)
'Close the file.
objStreamWriter.Close()
Exit Sub
End If
End If
End Sub
The code produce this file as output if it helps.
! 0 200 200 300 1
EG 10 80 10 10 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
PRINT

Answer 1

The iMZ printer comes pre configured to be in line mode. You have to change it to zpl mode so that it would parse either zpl or cpcl
Send this SGD to change the language of the printer.
! U1 setvar "device.languages" "zpl"

Answer 2

You convert the bitmap to a hex string
cpclData = cpclData & (currentValue.ToString("X2"))
then you encode this as byte[]
Return encoding.GetBytes(str)
end send the data to the printer:
thePrinterConn.Write(StrToByteArray(cpclData))
But I assume you have to encode the hex data string back to a byte array with the coresponding hex values converted back to a byte. In example a hex string of "FFFFFFFF" has to be converted back to byte[]{0xff,0xff,0xff,0xff}, exxcpet the printer language (CPCL?) reads hex string data and converts that back to byte itself.