In RPLCD version 1.0, some APIs were slightly changed. Previously the
CharLCD instance would provide default values for the pin numbers and the numbering mode. But that was changed, since it may be dangerous if these pins are connected to other hardware.
So if you have installed version 1.0 of RPLCD, you need to provide the pin numbering mode yourself. If your code previously looked like this:
from RPLCD import CharLCD lcd = CharLCD(cols=16, rows=2, pin_rs=37, pin_e=35, pins_data=[40, 38, 36, 32, 33, 31, 29, 23])
...and if you use the BOARD numbering scheme, then change the code like this: