Strange 4x20 LCD behaviour

Recently I had to source an 4x20 LCD (the attached one) and had to change the DEFINE LCD_DATAUS from 50 to 200 usec.

Also had to cut the Vo input (pin #3) from the ground and add a trimmer to adjust the bias for the screen contrast.

So many years I had no problem with the above and suddently one LCD ruins your day. Just to help others, please do add the damn trimmer and also if something does not display correctly, play with the timings.

Ioannis

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