Cursor position (0, 20) invalid on a 4x20 LCD

When initializing an LCD with “auto_linebreaks=False”, then writing a 20 character string to position (0, 0) seems to fail.

Traceback (most recent call last):
  File "/usr/local/bin/lcd.py", line 60, in <module>
    main(controller, addr, cols, rows)
  File "/usr/local/bin/lcd.py", line 28, in main
    loop(lcd, unit)
  File "/usr/local/bin/lcd.py", line 48, in loop
    lcd.write_string(datestring.ljust(lcd.lcd.cols))
  File "/usr/local/lib/python3.5/dist-packages/RPLCD/lcd.py", line 279, in write_string
    self.write(char)
  File "/usr/local/lib/python3.5/dist-packages/RPLCD/lcd.py", line 406, in write
    self.cursor_pos = newpos
  File "/usr/local/lib/python3.5/dist-packages/RPLCD/lcd.py", line 151, in _set_cursor_pos
    raise ValueError(msg.format(pos=value, lcd=self.lcd))
ValueError: Cursor position (0, 20) invalid on a 4x20 LCD.

[dbrgn]

I’m not sure. My preferred solution would be to simply continue writing to the memory. If you turn off auto linebreaks, then you’re on your own and any logic should be disabled.

This means that we’d have to disable bounds checks in that case.

[JsBergbau]

Anything new when this issue will be fixed in the official release you install with pip? Even resetting the Cursorposition doesn’t help. Second write leads to an exception. Since I return the Cursorposition to the beginning, this shouldn’t happen. If you wriite “ab” in the second write, display shows “ab3456789abcdefghijk”, so moving the cursor seems to work.

lcd.write_string("123456789abcdefghijk")
lcd.home()
lcd.cursor_pos=(0,0)
lcd.write_string("123456789abcdefghijk") #Exception