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dbrgn / RPLCD

A Raspberry Pi LCD library for the widely used Hitachi HD44780 controller, written in Python. GPIO (parallel) and I²C modes supported.
https://rplcd.readthedocs.io/en/latest/
MIT License
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Displays works sometimes and sometimes is blank or garbled. #102

Closed seanspotatobusiness closed 5 years ago

seanspotatobusiness commented 5 years ago

I am using a Raspberry Pi to send text to a 16x2 display which uses a SPLC780D controller. Sometimes the text displays correctly and sometimes the display is blank or garbled. Someone on the Raspberry Pi forum suggested that the timings assumed by the RPLCD library might not be correct. Is it possible to tweak these? Below is a video showing the problem and below that is the Python script I'm using.

I'm using RPLCD 1.2.2 on Raspbian Stretch.

https://www.youtube.com/watch?v=uTN3Vad8qDI

` import RPi.GPIO as GPIO from RPLCD.gpio import CharLCD import time

while True: lcd = CharLCD(pin_rs=36, pin_e=38, pins_data=[31, 33, 35, 37], numbering_mode=GPIO.BOARD, cols=16, rows=2, dotsize=8, auto_linebreaks=False,) lcd.write_string("abcdefghijklmnop\r\nqrstuvwxyz012345") time.sleep(1) lcd.clear() `

dbrgn commented 5 years ago

Hi. Can you try setting compat_mode=True in the CharLCD constructor? See #70 for more details.

seanspotatobusiness commented 5 years ago

Yes, this fixes the problem. Thanks very much.

dbrgn commented 5 years ago

Great. We should improve the docs, I opened #103 for that.