Newhaven Display Forum

Newhaven Products => OLEDs => Topic started by: tseyfarth on August 17, 2015, 12:04:31 AM

Title: Questions regarding NHD‐0220DZW‐AY5 & NHD‐0420DZW‐AY5
Post by: tseyfarth on August 17, 2015, 12:04:31 AM
Hello all,

I have several questions regarding the two above captions OLED displays.  I have been using the LCD versions of both of these [NHD-0220DZ-FL-YBW & NHD-0420DZ-FL-YBW].  The OLED's appear to work, but over time a character is lost on the left, like the display is shifted or something.

I would like to know:
1)  May I please have a list of compatible Chipsets?  I know the OLED is proprietary and is "based on the LCD version".  But that is not helping me much.  I would like to use either 8bit or 4 bit, I have all pins connected to uC.  A Selection of Chipsets would be very helpful for my engineering team.

I believe we *think* these are compatible chip sets but not sure since we cannot find any real answers.
ST7066U
HD44780
KS0063
KS0065B

2)  May I please have sample start up code for these OLED's
3) On another post, the respondant said that there is a timing issue - can anyone elaborate on that - ie the difference(s) between the LCD and OLED displays for Chipset x?
4) Does anyone have any idea why the chars on the left would be disappearing over time?  On a power cycle, they all appear properly (saved in EEPROM).  However, even with clear screen and reinitialization, this still occurs - it takes up to 3 weeks to become evident.

Thank you in advance!
Tim
Title: Re: Questions regarding NHD‐0220DZW‐AY5 & NHD‐0420DZW‐AY5
Post by: Saurabh_B on August 17, 2015, 08:47:23 AM
Hi,

The most similar controller inside the OLED display's is the ST7066U. The commands that are used for displays with this controller will be the same as the commands used by the OLED displays. The difference will be in the amount of time required to execute the commands or time to write the data onto the display.

There is a sample initialization sequence on pages 20 and 21 in the datasheet of the display. At the same time any program used for the  ST7066U will work for this display; but the code would need to have the timing adjusted for the new display.
The links for the datasheets for the OLED displays are here:
NHD-0420DZW-AY5 (http://www.newhavendisplay.com/specs/NHD-0420DZW-AY5.pdf)
NHD-0220DZW-AY5 (http://www.newhavendisplay.com/specs/NHD-0220DZW-AY5.pdf)

When we say timing issue it usually refers to the time between consecutive commands or data writes to the display. For instance with the ST7066U many of the commands will have a max execution time of 37us, where as the OLED display will have a max execution time of 600us.

If the time you give the commands to execute to the display are on the borderline of the max execution time the error wont occur at first, but over time you will start seeing various errors occur with the display such as a shift in the display.

Title: Re: Questions regarding NHD‐0220DZW‐AY5 & NHD‐0420DZW‐AY5
Post by: tseyfarth on August 19, 2015, 01:09:43 PM
May I please have sample code for these?

Thank you,
Tim
Title: Re: Questions regarding NHD‐0220DZW‐AY5 & NHD‐0420DZW‐AY5
Post by: Saurabh_B on August 20, 2015, 09:51:26 AM
These codes will work for the displays, they were written for the ST7066U controller; so you would need to increase some of the time between the instructions.
8-bit C code:          http://www.newhavendisplay.com/app_notes/8_bit_character_C.txt (http://www.newhavendisplay.com/app_notes/8_bit_character_C.txt)
4-bit Basic code:    http://www.newhavendisplay.com/app_notes/4_bit_character.txt (http://www.newhavendisplay.com/app_notes/4_bit_character.txt)

If you want the serial code please email nhtech@newhavendisplay.com