I have just recently purchased some displays from New Haven Display and the drivers listed are SPLC780D OR ST7066U, from doing some reading prior to purchase, I saw that it is compatible to the Arduino because it's the same coding for the HD44780 driver (if I worded that incorrectly I apologize). I had a sketch running already that had a HD44780 screen on it and wanted to change the screen out to this new 4x20 display I purchased (NHD-0420AZ-FL-GBW-3V3). When I hooked it up, to no surprise it was NOT working properly. I tinkered around a little, did some reading (which has confused me more) and here I am!
To make this easier, I'm working off of the "Hello World" sketch which has the pin out as follows:
* LCD RS pin to digital pin 12
* LCD Enable pin to digital pin 11
* LCD D4 pin to digital pin 5
* LCD D5 pin to digital pin 4
* LCD D6 pin to digital pin 3
* LCD D7 pin to digital pin 2
* LCD R/W pin to ground
* 10K resistor:
* ends to +5V and ground
* wiper to LCD VO pin (pin 3)
The display is on, and working it just has symbols and blacked out segments...
Here is the datasheet from the LCD display: http://www.newhavendisplay.com/specs/NHD-0420AZ-FL-GBW-3V3.pdf
Any help would be much appreciated! If I can supply any additional information please let me know what you need. Thank you in advanced for your help!