SparkFun Forums

[reddgreen]

Hi All,
New to electronics. Ive found that there are quite a few 16x2 Character LCD available, most based on Hitachi HD44780. The HD44780 states a wide range of supply voltages. From what I can read, the HD44780 driver can run fine on 3.3v.

But there are quite a few LCD modules with HD44780 integrated, that require 5v.

Q1: Is this because the particular LCD module they use, requires 5v?

Q2: Since the HD44780 can run on 3.3v, can I run a LCD module that uses a HD44780, on 3.3v, e.g. as supplied by a Raspberry Pi?

Thanks!
Mike

[Valen]

The logic part of the chip may work at 3.3 volt. But in order to get pixel/lcd segments with enough contrast on the display the VLCD pin might need negative voltage (below gnd) in order to show something.

This page sheds some light, with a solution.
http://jap.hu/electronic/lcd_at_3_volts.html

[darrellg]

Sparkfun has several displays of that type that work with a 3.3V supply.

[reddgreen]

Thanks everyone!