Trouble with Optrex 4x20 LCD module

[skimask]

By the way, I use

DEFINE LCD_COMMANDUS 2000
DEFINE LCD_DATAUS 100

for the LCD timing. If you go faster on the data, such as 50 us, then
the Optrex 4-line display will be garbled.

Most likely, you can reduce that commandus down quite a bit, like I said, maybe 200.
The dataus at 100, sounds good enough. Maybe throw another cap across the power/ground at the LCD and see if it'll take a lower number; it might, might not, who knows.