Android Question EscPosPrinter and Android 11

Pedro Caldeira · Oct 1, 2021

Hello All,
My App prints (EscPOS Bluetooth printer) without errors or issues in Android 8 thru 10, but in Android 11 (Samsung Tab Active3) it can't print the whole ticket
It always stop half way, even with resets between the prints, and after it misprints, I cannot print anything else.
I have to disconnect, reconnect and then printer to be able to print another ticket.

Any ideas ?

Thanks

jahswant · Oct 1, 2021

Pedro Caldeira said:
Hello All,
My App prints (EscPOS Bluetooth printer) without errors or issues in Android 8 thru 10, but in Android 11 (Samsung Tab Active3) it can't print the whole ticket
It always stop half way, even with resets between the prints, and after it misprints, I cannot print anything else.
I have to disconnect, reconnect and then printer to be able to print another ticket.

Any ideas ?

Thanks

Do a complete buffer of your text before printing. Don't a line at a time. Print everthing once.

Pedro Caldeira · Oct 1, 2021

jahswant said:
Do a complete buffer of your text before printing. Don't a line at a time. Print everthing once.

How so ?
Crate a string with the full content and then print the string ?
I have bitmaps also

jahswant · Oct 1, 2021

Pedro Caldeira said:
How so ?
Crate a string with the full content and then print the string ?
I have bitmaps also

Make the string one. send the bitmap followed bybthe string.

Pedro Caldeira · Oct 1, 2021

jahswant said:
Make the string one. send the bitmap followed bybthe string.

Same result. In android 11 it doesn't print the second one all the way

Pedro Caldeira · Oct 4, 2021

To have a printer shared between activity what would be the best practice ?
Declare Public BTPrinter as EscPosPrinter in the Starter service, declare it in main ? Declare Private BTPrinter as EscPosPrinter in every activity_create ?

dws · Oct 15, 2021

i have the same problem with samsung TAB A7 Lite 2021

Any suggestion ?

Pedro Caldeira · Oct 18, 2021

I have solved it, by not complicating it.
I have several activies that can print, so I initialized and connected the EscPosPrinter object in the start of each, do all the printing required and disconnect the printer on exit (Activity.close)
That done it for me.

dws · Oct 19, 2021

Pedro Caldeira said:
I have solved it, by not complicating it.
I have several activies that can print, so I initialized and connected the EscPosPrinter object in the start of each, do all the printing required and disconnect the printer on exit (Activity.close)
That done it for me.

Thanks For Replay ... my problem is on printer. (Different model)

mostafa_ibrahim38 · Apr 10, 2022

Pedro Caldeira said:
I have solved it, by not complicating it.
I have several activies that can print, so I initialized and connected the EscPosPrinter object in the start of each, do all the printing required and disconnect the printer on exit (Activity.close)
That done it for me.

can you help me to solve this problem,please?

Pedro Caldeira · Apr 11, 2022

mostafa_ibrahim38 said:
can you help me to solve this problem,please?

Care to elaborate ? Need help in exactly what ?

mostafa_ibrahim38 · Apr 11, 2022

in attach code of bluetooth and print activity what's the matter??? in android 11 print half of receipt

Pedro Caldeira said:
Care to elaborate ? Need help in exactly what ?

in attach code of bluetooth and print activity what's the matter??? in android 11 print half of receipt

mostafa_ibrahim38 · Apr 13, 2022

Pedro Caldeira said:
Care to elaborate ? Need help in exactly what ?

Did you get a solution?

Pedro Caldeira · Apr 14, 2022

mostafa_ibrahim38 said:
Did you get a solution?

For me nothing worked until I did the following
Initialize the printer on each activity
Connect before every print job
disconnect after printing was complete

but I had to print from a multi activity App

DonManfred · Apr 14, 2022

Pedro Caldeira said:
until I did the following

Have you tried to do all the Printer-Communication from the Starterservice (or any other Service) and call the print-methods (in the service) from all activities then?

mostafa_ibrahim38 · Apr 14, 2022

Pedro Caldeira said:
For me nothing worked until I did the following
Initialize the printer on each activity
Connect before every print job
disconnect after printing was complete

but I had to print from a multi activity App

the error apppear this message
2022-04-13 11:33:10.692 4721-4825/? E/bt_btif_sock_rfcomm: send data to app error writing RFCOMM data back to app: Broken pipe
in attach put bluetooth operation

MicroDrie · Apr 15, 2022

You see an abruptly disconnection in Android with the error message "E/bt_btif_sock_rfcomm" and a half printed receipt. The printer has a limited internal memory buffer in which the printer data is temporarily stored. In this case, full = full. If the buffer is about to become full, the printer will send an XOFF command with the intention to directly stop receiving more incommoding data. If an OS is more efficient at processing the printer data, sending it faster, or Bluetooth than the printer can print, the printer's internal buffer becomes full.

When the buffer can receive data again, it sends an XON character. If your program does not stop sending printer data after an XOFF message, the printer will hang. Only what is in the buffer is still printed and the printer stops immediately (thats why you see a half receipt). If that is in the middle of a printer control command, my experience is that almost no printer survives this without a power off/on action (thats why you must hard reset the printer).

What I am missing in the program is checking whether the printer has an XOFF status message with the character Pause transmission code XOFF, ASCII codec DC3, 19 decimal or 13 Hexadecimal. The XON Resume transmission ASCII code is DC1, ASCII code 17 or 11 Hexadecimal. All this is missing from the program.

This so-called XON/XOFF printer handshake could of course be hidden in either the OS or the printer driver. Another possibility is that the XON/XOFF printer handshake is turned off in the printer setting because, for example, the printer setting is based on a serial or parallel interface hardware printer handshake.

My question is how the printer settings are. This can often be printed out by pressing the on/off line feed button or a reset button for some time when switching on the printer. See the user manual for the correct actions.

mostafa_ibrahim38 · Apr 16, 2022

MicroDrie said:
You see an abruptly disconnection in Android with the error message "E/bt_btif_sock_rfcomm" and a half printed receipt. The printer has a limited internal memory buffer in which the printer data is temporarily stored. In this case, full = full. If the buffer is about to become full, the printer will send an XOFF command with the intention to directly stop receiving more incommoding data. If an OS is more efficient at processing the printer data, sending it faster, or Bluetooth than the printer can print, the printer's internal buffer becomes full.

When the buffer can receive data again, it sends an XON character. If your program does not stop sending printer data after an XOFF message, the printer will hang. Only what is in the buffer is still printed and the printer stops immediately (thats why you see a half receipt). If that is in the middle of a printer control command, my experience is that almost no printer survives this without a power off/on action (thats why you must hard reset the printer).

What I am missing in the program is checking whether the printer has an XOFF status message with the character Pause transmission code XOFF, ASCII codec DC3, 19 decimal or 13 Hexadecimal. The XON Resume transmission ASCII code is DC1, ASCII code 17 or 11 Hexadecimal. All this is missing from the program.

This so-called XON/XOFF printer handshake could of course be hidden in either the OS or the printer driver. Another possibility is that the XON/XOFF printer handshake is turned off in the printer setting because, for example, the printer setting is based on a serial or parallel interface hardware printer handshake.

My question is how the printer settings are. This can often be printed out by pressing the on/off line feed button or a reset button for some time when switching on the printer. See the user manual for the correct actions.

Unfortunately, the problem is not with the printer, because it prints perfectly with all Android devices except Android 11

f0raster0 · Apr 17, 2022

mostafa_ibrahim38 said:
Unfortunately, the problem is not with the printer, because it prints perfectly with all Android devices except Android 11

I use Android11 (and other android versions)
The example EscPOSPrinter works with not porblem at all.

Have you tested the example using Android11?

if the issue is not in your printer maybe it is in your code.. better post a small example showing the issue

jahswant · Apr 17, 2022

f0raster0 said:
If the issue is not in your printer maybe it is in your code.. better post a small example showing the issue

You should create a single string buffer and send it once to the printer instead of sending multiple single strings.

Android Question EscPosPrinter and Android 11

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