Using a 5volt LCD with 3.3volt pic

[be80be]

Here a simple way to use a sharp or HD44780 5 volt LCD with a 3.3 volt chip

Just hook the to the pot wiper to use the negative volts to get better contrast.

 

[MikeMl]

How do solve the problem that a 5V LCD wants logic 5V swings; not 3.3V?

 

[be80be]

Where you get that idea I've tried a bunch and haven't found one that need 5 for logic to work they need to be -5 from vdd on the contrast pin or V0 pin so you can see them work

 

[DirtyLude]

Goog post. Yes, I've implemented tiny 5v regs in order to just do the display in the past. I've never found one where the logic needed to be 5v.

 

[Kryten]

Here is a page with voltage guides..

Logic Voltage Thresholds for TTL, CMOS, LVCMOS, and GTLP IC's

And it shows that 5v TTL has a threshold of 2 Volts so 3.3v will be sufficient to set the gate high