Getting Garbage Display

WHen doing several updates in a row, the output on the LCD becomes corrupted. Garbage characters and the only way out is a full reset. This is the relevant code:

        lcd.clear()
        lcd.cursor_pos = (0, lineStartPos(lcdLine1))
        lcd.write_string(str(lcdLine1))
        lcd.cursor_pos = (1, lineStartPos(lcdLine2))
        lcd.write_string(str(lcdLine2))
        lcd.cursor_pos = (2, lineStartPos(lcdLine3))
        lcd.write_string(str(lcdLine3))
        lcd.cursor_pos = (3, 0)
        lcd.write_string("Target:")
        lcd.write_string(str(targetTemp))
        lcd.write_string(chr(223) + " ")
        lcd.write_string("Temp:")
        lcd.write_string(str(currentTemp))
        lcd.write_string(chr(223))

lineStartPos is a function to determine center point of the text. I can update the same content perhaps 6 times in a row but after that it becomes corrupt. Thanks.

[albedozero]

The master branch fixes the problem for me, when I use compat_mode=True. Works in python2 and python3.

[dbrgn]

The pull request #91 was merged to master. It adds a compatibility mode with longer wait times. This might help when an LCD requires timings that are out of spec for the HD44780, or if the clock isn’t correct.

It would be great if one of the affected people could test the current master branch of this library, to see if it fixes the issue. You also need to pass in the compat_mode=True parameter when initializing the CharLCD class in order to enable this compatibility mode.