diff --git a/doc/spelling_wordlist.txt b/doc/spelling_wordlist.txt index 0fc9cf4..38db9e1 100644 --- a/doc/spelling_wordlist.txt +++ b/doc/spelling_wordlist.txt @@ -91,6 +91,7 @@ docstrings ean Ean encodable +Errno fff fullimage io @@ -124,6 +125,7 @@ Todo traceback udev usb +USBTimeoutError usec virtualenvs whitespaces diff --git a/doc/user/usage.rst b/doc/user/usage.rst index 30e1d44..3bcc4eb 100644 --- a/doc/user/usage.rst +++ b/doc/user/usage.rst @@ -213,6 +213,14 @@ If something is wrong, an ``CharCodeError`` will be raised. After you have manually set the codepage the printer won't change it anymore. You can revert to normal behavior by setting charcode to ``AUTO``. +Resolving bus timeout issues during printing images +--------------------------------------------------- + +If an error message such as "USBTimeoutError: [Errno 110] Operation timed out" occurs, +setting a sleep time between printing fragments can help. + +This can be done with the :meth:`.set_sleep_in_fragment()` method. + Advanced Usage: Print from binary blob -------------------------------------- diff --git a/src/escpos/escpos.py b/src/escpos/escpos.py index daad90d..48e5296 100644 --- a/src/escpos/escpos.py +++ b/src/escpos/escpos.py @@ -12,6 +12,7 @@ This module contains the abstract base class :py:class:`Escpos`. from __future__ import annotations import textwrap +import time import warnings from abc import ABCMeta, abstractmethod # abstract base class support from re import match as re_match @@ -123,6 +124,9 @@ class Escpos(object, metaclass=ABCMeta): # object -> The connection object (Usb(), Serial(), Network(), etc.) _device: Union[Literal[False], Literal[None], object] = False + # sleep time in fragments: + _sleep_in_fragment_ms: int = 0 + def __init__(self, profile=None, magic_encode_args=None, **kwargs) -> None: """Initialize ESCPOS Printer. @@ -178,6 +182,21 @@ class Escpos(object, metaclass=ABCMeta): """ raise NotImplementedError() + def set_sleep_in_fragment(self, sleep_time_ms: int) -> None: + """Configures the currently active sleep time after sending a fragment. + + If during printing an image an issue like "USBTimeoutError: [Errno 110] + Operation timed out" occurs, setting this value to roughly 300 + milliseconds can help resolve the issue. + + :param sleep_time_ms: sleep time in milliseconds + """ + self._sleep_in_fragment_ms = sleep_time_ms + + def _sleep_in_fragment(self) -> None: + """Sleeps the preconfigured time after sending a fragment.""" + time.sleep(self._sleep_in_fragment_ms / 1000) + def image( self, img_source, @@ -246,6 +265,7 @@ class Escpos(object, metaclass=ABCMeta): impl=impl, fragment_height=fragment_height, ) + self._sleep_in_fragment() return if impl == "bitImageRaster":