EPSON TM-m30III randomly fails to print images

[rubenbroman]

I have:

• searched open and closed issues for duplicates

Bug description

With random intervals images won't print properly but instead the image data as characters, see image. The failure interval is between 8 and 300 prints. I've been able to reproduce this on 3 different EPSON TM-m30III printers.

Steps to reproduce

from escpos import printer
from time import sleep

p = printer.Usb(0x04b8, 0x0e32)

while True:
    p.image("/path/to/image.jpg")
    p.cut()
    sleep(3)

I've used this image when reproducing the error, but it happens with different images in different sizes.

Device info

Printer: EPSON TM-m30III

• python-escpos version: 3.1
• python version: CPython v3.11.2
• platform: Linux-6.1.0-rpi7-rpi-2712-aarch64-with-glibc2.36
• printer driver USB is usable: True
• printer driver File is usable: True
• printer driver Network is usable: True
• printer driver Serial is usable: True
• printer driver LP is usable: True
• printer driver Dummy is usable: True
• printer driver CupsPrinter is usable: True
• printer driver Win32Raw is usable: False

[rubenbroman]

It seems like setting fragment_height to 100 pixels fixes the bug. So probably a buffer error on the printer. I will see if I can replicate the error with p.image(file,fragment_height=100) and report back here.