Android Question How print QRCode on ESC/POS printer

[dws]

Hello

I would like some help on printing QRCode to ESC / POS (Bluetooth Printer)

1. I use QRGenerator to create QRCode in a Bitmap object
2. I use EscPosPrinter.bas for printing.
3. If I use (WriteQRCode) from EscPosPrinter the QRCode is printed but you do not scan at all.
4. If I use (PrintImage) the QRCode is printed diagonally

4.1. Here is a small example of my code for printing QRCode as an image

' QrGen is QRGenerator class
' Prn   is EscPosPrinter class
' sQRString is my string with 114 length for creating QRCode

' 1. Create an image with QRCode
dim QrBmp as Bitmap = QrGen.Create(sQRString)

' 1.1 If assing QrBmp on view is currect '

' 2. Print QRCode Image with EscPosPrinter object
dim img as AnImage = Prn.ImageToBWIMage(QrGen)
img = Prn.ThresholdImage(img, 128)
img = Prn.PackImage(img)

' 3. Final Print QRCode Image
Prn.PrintImage(img)

the result is a diagonal print of QRCode image.

Any Help or Is there an example or way to print the QRCode either as an image or directly as a QRCode?

Thanks ...

 

[Kevin Hartin]

Hello

I would like some help on printing QRCode to ESC / POS (Bluetooth Printer)

1. I use QRGenerator to create QRCode in a Bitmap object
2. I use EscPosPrinter.bas for printing.
3. If I use (WriteQRCode) from EscPosPrinter the QRCode is printed but you do not scan at all.
4. If I use (PrintImage) the QRCode is printed diagonally

4.1. Here is a small example of my code for printing QRCode as an image

' QrGen is QRGenerator class
' Prn   is EscPosPrinter class
' sQRString is my string with 114 length for creating QRCode

' 1. Create an image with QRCode
dim QrBmp as Bitmap = QrGen.Create(sQRString)

' 1.1 If assing QrBmp on view is currect '

' 2. Print QRCode Image with EscPosPrinter object
dim img as AnImage = Prn.ImageToBWIMage(QrGen)
img = Prn.ThresholdImage(img, 128)
img = Prn.PackImage(img)

' 3. Final Print QRCode Image
Prn.PrintImage(img)

the result is a diagonal print of QRCode image.

Any Help or Is there an example or way to print the QRCode either as an image or directly as a QRCode?

Thanks ...

I have been doing the same using QRgenerator and ESCPOSprinter and found that the diagonal tearing is because the source QRcode image is not a multiple of 8 or 24. I found that the best results come from generating the QRcode at 512 px if I know it is going to an 80mm printer or 360 if it is going to a 58mm printer.

for printing, I do the following and it is reliable.

Dim qr As QRGenerator
Dim Printer1 As EscPosPrinter
Dim iwidth as Int = 512

Dim vl As String = "AlhSU1lTWldMMzczWlFYRjQBAAAAAQAAAEwLAwAAAAAAAAABcQ5zvzUAAAAqZAw1njZ%2F8bGFxY2L6p3ncqt3yS71%2BktS7R0f2wcnLFyVqQita0mP9idV5gq7D6AzKqXHnd2vkAyJ%2BdeBGkbRXt7ltGUQb%2Fs3g3DEZYAY%2BL2p9t3c5rAyeTp1BJckyV6KCggot5FHJ3iA3r6Lmtbfje%2FxnWnCmrKzRgsTdVgexzE9ZZhgAd0B7uw5zG8QyzN1STiAfs2igQwn2Bw%2BmdmOeBqq2Cy9bULw3mCeyS2Czz1ab4129Q%2BOU1HuLlb7AH9CYBIHA5GL7ZHJbpr7EEEGjQf7iLTK69b6LSSo4jBAOh9EdmvzwgnQz4oJht68ac%2FYzCpAYwQTIFDlCdMoxFbSYNxmErLoJUHbUvza6iLfC8kRgcWPVpaQ7zo%2FKM4bZniP%2FY9ypfBK%2BEcjpmDpD4xbKIipXGQQ%2FlE2tUxT7ad8BPmaCUlUBAAtHu6VfIGZXOxayCRf3o1vj6ORD9eQxMLX47%2Fs2edogY5W6ThVakmJrzMd%2BdQWDwe3x6ya4kGEl2qUoHBqUmNBBE9tlvmP8oI6TaKZtDQn4wBfcwjfStN9U2X%2BBOwNCfBCjwKsZLF49dex5wfNFF%2FfDIxLONWEmP3dtPezpkkcinK6QkU91uiu2HEgcQVFj9VYgX3H%2B8fEAwLYRS6T%2B%2FUhqn0T3Iaqomt9SAcgARSbDbPPqwg%2FdGj7aw%3D%3D"
Dim QRtext As String = "https://frontendui.test.taxcore.dti.rs/v/?vl="&vl

qr.Initialize(iwidth)
img = qr.Create(QRtext)
Dim out As OutputStream
out = File.OpenOutput(B4XPages.MainPage.dbPath, "QRcode.jpg", False)
img.WriteToStream(out, 100, "JPEG")
out.Close

Dim QRimage As AnImage = Printer1.ImageToBWIMage(bmp)
QRimage = Printer1.ThresholdImage(QRimage, 128)
QRimage = Printer1.PackImage(QRimage)
Printer1.PrintImage(QRimage)

Regards,
Kev

 

[dws]

I have been doing the same using QRgenerator and ESCPOSprinter and found that the diagonal tearing is because the source QRcode image is not a multiple of 8 or 24. I found that the best results come from generating the QRcode at 512 px if I know it is going to an 80mm printer or 360 if it is going to a 58mm printer.

for printing, I do the following and it is reliable.

Dim qr As QRGenerator
Dim Printer1 As EscPosPrinter
Dim iwidth as Int = 512

Dim vl As String = "AlhSU1lTWldMMzczWlFYRjQBAAAAAQAAAEwLAwAAAAAAAAABcQ5zvzUAAAAqZAw1njZ%2F8bGFxY2L6p3ncqt3yS71%2BktS7R0f2wcnLFyVqQita0mP9idV5gq7D6AzKqXHnd2vkAyJ%2BdeBGkbRXt7ltGUQb%2Fs3g3DEZYAY%2BL2p9t3c5rAyeTp1BJckyV6KCggot5FHJ3iA3r6Lmtbfje%2FxnWnCmrKzRgsTdVgexzE9ZZhgAd0B7uw5zG8QyzN1STiAfs2igQwn2Bw%2BmdmOeBqq2Cy9bULw3mCeyS2Czz1ab4129Q%2BOU1HuLlb7AH9CYBIHA5GL7ZHJbpr7EEEGjQf7iLTK69b6LSSo4jBAOh9EdmvzwgnQz4oJht68ac%2FYzCpAYwQTIFDlCdMoxFbSYNxmErLoJUHbUvza6iLfC8kRgcWPVpaQ7zo%2FKM4bZniP%2FY9ypfBK%2BEcjpmDpD4xbKIipXGQQ%2FlE2tUxT7ad8BPmaCUlUBAAtHu6VfIGZXOxayCRf3o1vj6ORD9eQxMLX47%2Fs2edogY5W6ThVakmJrzMd%2BdQWDwe3x6ya4kGEl2qUoHBqUmNBBE9tlvmP8oI6TaKZtDQn4wBfcwjfStN9U2X%2BBOwNCfBCjwKsZLF49dex5wfNFF%2FfDIxLONWEmP3dtPezpkkcinK6QkU91uiu2HEgcQVFj9VYgX3H%2B8fEAwLYRS6T%2B%2FUhqn0T3Iaqomt9SAcgARSbDbPPqwg%2FdGj7aw%3D%3D"
Dim QRtext As String = "https://frontendui.test.taxcore.dti.rs/v/?vl="&vl

qr.Initialize(iwidth)
img = qr.Create(QRtext)
Dim out As OutputStream
out = File.OpenOutput(B4XPages.MainPage.dbPath, "QRcode.jpg", False)
img.WriteToStream(out, 100, "JPEG")
out.Close

Dim QRimage As AnImage = Printer1.ImageToBWIMage(bmp)
QRimage = Printer1.ThresholdImage(QRimage, 128)
QRimage = Printer1.PackImage(QRimage)
Printer1.PrintImage(QRimage)

Regards,
Kev
View attachment 120535

Thanks Kevin
What is bmp in this line (Dim QRimage As AnImage = Printer1.ImageToBWIMage(bmp))

 

[Kevin Hartin]

Thanks Kevin
What is bmp in this line (Dim QRimage As AnImage = Printer1.ImageToBWIMage(bmp))

bmp is the image file generated by QRgenerate

Dim qr As QRGenerator
Dim Printer1 As EscPosPrinter
Dim iwidth as Int = 512

Dim vl As String = "AlhSU1lTWldMMzczWlFYRjQBAAAAAQAAAEwLAwAAAAAAAAABcQ5zvzUAAAAqZAw1njZ%2F8bGFxY2L6p3ncqt3yS71%2BktS7R0f2wcnLFyVqQita0mP9idV5gq7D6AzKqXHnd2vkAyJ%2BdeBGkbRXt7ltGUQb%2Fs3g3DEZYAY%2BL2p9t3c5rAyeTp1BJckyV6KCggot5FHJ3iA3r6Lmtbfje%2FxnWnCmrKzRgsTdVgexzE9ZZhgAd0B7uw5zG8QyzN1STiAfs2igQwn2Bw%2BmdmOeBqq2Cy9bULw3mCeyS2Czz1ab4129Q%2BOU1HuLlb7AH9CYBIHA5GL7ZHJbpr7EEEGjQf7iLTK69b6LSSo4jBAOh9EdmvzwgnQz4oJht68ac%2FYzCpAYwQTIFDlCdMoxFbSYNxmErLoJUHbUvza6iLfC8kRgcWPVpaQ7zo%2FKM4bZniP%2FY9ypfBK%2BEcjpmDpD4xbKIipXGQQ%2FlE2tUxT7ad8BPmaCUlUBAAtHu6VfIGZXOxayCRf3o1vj6ORD9eQxMLX47%2Fs2edogY5W6ThVakmJrzMd%2BdQWDwe3x6ya4kGEl2qUoHBqUmNBBE9tlvmP8oI6TaKZtDQn4wBfcwjfStN9U2X%2BBOwNCfBCjwKsZLF49dex5wfNFF%2FfDIxLONWEmP3dtPezpkkcinK6QkU91uiu2HEgcQVFj9VYgX3H%2B8fEAwLYRS6T%2B%2FUhqn0T3Iaqomt9SAcgARSbDbPPqwg%2FdGj7aw%3D%3D"
Dim QRtext As String = "https://frontendui.test.taxcore.dti.rs/v/?vl="&vl

qr.Initialize(iwidth)
img = qr.Create(QRtext)
Dim out As OutputStream
out = File.OpenOutput(File.DirInternal, "QRcode.jpg", False)
img.WriteToStream(out, 100, "JPEG")
out.Close

Dim bmp As Bitmap
bmp.Initialize(File.DirInternal, "QRcode.jpg")  
bmp = bmp.Resize(imgWidth, imgWidth, True)   ' not really needed as we QRgenerated at iwidth 512
Dim QRimage As AnImage = Printer1.ImageToBWIMage(bmp)
QRimage = Printer1.ThresholdImage(QRimage, 128)
QRimage = Printer1.PackImage(QRimage)
Printer1.PrintImage(QRimage)

 

[dws]

bmp is the image file generated by QRgenerate

Dim qr As QRGenerator
Dim Printer1 As EscPosPrinter
Dim iwidth as Int = 512

Dim vl As String = "AlhSU1lTWldMMzczWlFYRjQBAAAAAQAAAEwLAwAAAAAAAAABcQ5zvzUAAAAqZAw1njZ%2F8bGFxY2L6p3ncqt3yS71%2BktS7R0f2wcnLFyVqQita0mP9idV5gq7D6AzKqXHnd2vkAyJ%2BdeBGkbRXt7ltGUQb%2Fs3g3DEZYAY%2BL2p9t3c5rAyeTp1BJckyV6KCggot5FHJ3iA3r6Lmtbfje%2FxnWnCmrKzRgsTdVgexzE9ZZhgAd0B7uw5zG8QyzN1STiAfs2igQwn2Bw%2BmdmOeBqq2Cy9bULw3mCeyS2Czz1ab4129Q%2BOU1HuLlb7AH9CYBIHA5GL7ZHJbpr7EEEGjQf7iLTK69b6LSSo4jBAOh9EdmvzwgnQz4oJht68ac%2FYzCpAYwQTIFDlCdMoxFbSYNxmErLoJUHbUvza6iLfC8kRgcWPVpaQ7zo%2FKM4bZniP%2FY9ypfBK%2BEcjpmDpD4xbKIipXGQQ%2FlE2tUxT7ad8BPmaCUlUBAAtHu6VfIGZXOxayCRf3o1vj6ORD9eQxMLX47%2Fs2edogY5W6ThVakmJrzMd%2BdQWDwe3x6ya4kGEl2qUoHBqUmNBBE9tlvmP8oI6TaKZtDQn4wBfcwjfStN9U2X%2BBOwNCfBCjwKsZLF49dex5wfNFF%2FfDIxLONWEmP3dtPezpkkcinK6QkU91uiu2HEgcQVFj9VYgX3H%2B8fEAwLYRS6T%2B%2FUhqn0T3Iaqomt9SAcgARSbDbPPqwg%2FdGj7aw%3D%3D"
Dim QRtext As String = "https://frontendui.test.taxcore.dti.rs/v/?vl="&vl

qr.Initialize(iwidth)
img = qr.Create(QRtext)
Dim out As OutputStream
out = File.OpenOutput(File.DirInternal, "QRcode.jpg", False)
img.WriteToStream(out, 100, "JPEG")
out.Close

Dim bmp As Bitmap
bmp.Initialize(File.DirInternal, "QRcode.jpg")
bmp = bmp.Resize(imgWidth, imgWidth, True)   ' not really needed as we QRgenerated at iwidth 512
Dim QRimage As AnImage = Printer1.ImageToBWIMage(bmp)
QRimage = Printer1.ThresholdImage(QRimage, 128)
QRimage = Printer1.PackImage(QRimage)
Printer1.PrintImage(QRimage)

Thanks Kevin ...

I understood it, I just wanted to confirm it ....
Now I face another problem. I want the QRCode to print a maximum of 256x256 ον Bluetooth pos printer with 58mm paper

 

[Kevin Hartin]

Thanks Kevin ...

I understood it, I just wanted to confirm it ....
Now I face another problem. I want the QRCode to print a maximum of 256x256 ον Bluetooth pos printer with 58mm paper

set the size to 256 when you generate the image. how many characters do you need to encode in the QR? our tax system here requires almost 800 characters to be encoded, so we end up with a very big QR, with fine details that can have issues at smaller sizes

 

[dws]

set the size to 256 when you generate the image. how many characters do you need to encode in the QR? our tax system here requires almost 800 characters to be encoded, so we end up with a very big QR, with fine details that can have issues at smaller sizes

144 Characters i need to QRCode

I have already declared 256 but again the printing is not done correctly
I need to make QRCode for string like this ( https://www1.gsis.gr/tameiakes/mywe...69D0FF6CBDB1E46A8B15BDE3EE0E25FABD28210723.20 )