Newhaven Display Forum

Newhaven Products => Character LCDs => Topic started by: wedge on July 06, 2014, 12:52:19 AM

Title: OLED Character display - Some commands don't work
Post by: wedge on July 06, 2014, 12:52:19 AM
I'm using a NHD-0216KZW-AY5 in 4-bit parallel mode, using the busy signal (not using blind delays).  The device initializes just fine, and prints text to the screen successfully.
However, the screen does not respond to the Clear Screen command, and the Move Cursor command.  It simply does nothing when those commands are sent.  There may or may not be other commands it's not responding to, but those are the only ones I've noticed.

If I swap out the screen for any other HD44780 compatible, and leave all other code and connections exactly the same, then everything is working perfectly.
Title: Re: OLED Character display - Some commands don't work
Post by: Michael_L on July 08, 2014, 09:29:43 AM
The display is HD44780 compatible, however there are some minor timing differences that sometimes need to be accounted for (depending on your micro).  I have replicated this with an Arduino, and have found that the busy flag will 'hang' after the clear display command if there is not a delay present after the command is sent (and before the busy flag is checked).  Please add a 2ms delay after sending this these commands, as this fixed the issue for me.