Prototype in Elektor Lab
Not too difficult to solder and the hardware isn't too complicated, so I didn't expect much issues. However, I was unpleasently surprised by the LCD I ordered (Powertip PC1604LRU-AWB-H), which appeared to need a negative voltage on the contrast pin (VO on pin 3) to get readable text on the display. For the time being this was solved with the good-old diode trick (schematic) to get one end of the contrast potmeter at -0.7V. The result is not really encouraging, but I can still use this LCD before I get a more modern LCD in stead.
Negative contrast voltage on LCD modules was quite common 'in the old days', but I hadn't seen one for years!