Newhaven Display Forum

Newhaven Products => OLEDs => Topic started by: riaz on September 08, 2014, 10:57:39 AM

Title: NHD-2.8-25664 OLED Display
Post by: riaz on September 08, 2014, 10:57:39 AM
hi everyone,

i am using an oled in my project but am have great difficulty in getting it to work.

i am using parallel 6800 interface.

i can send command oxA4  and the display goes all blank.
i then send command 0xA5 and display all lit.

i have used the init sequence as per data sheet and i get display showing some pixels while other and un-lit (semi random).

i have noticed,  after sending data (instruction)  the next command instruction is ignored. this leads me to thinks there is problem with my sending data command.

i can't see much difference between command and data instruction except the DC line.

i have  run Checkerboard_25664() and i get nothing.

please help

many thanks
Title: Re: NHD-2.8-25664 OLED Display
Post by: riaz on September 08, 2014, 11:08:52 AM
when i said the screen has some pixels lit (randomly) it actually looks much like The Matrix screen saver.
Title: Re: NHD-2.8-25664 OLED Display
Post by: Michael_L on September 09, 2014, 08:49:53 AM
Since you said you are sending commands that work, followed by ones that don't, it leads me to believe that your timing is too fast.  Try either slowing down your program speed (easiest way initially) or trying adding delays after your write functions.
Title: Re: NHD-2.8-25664 OLED Display
Post by: riaz on September 10, 2014, 05:45:17 AM
thanks for your response.

if anything, timings are too slow (in ms) i will speed this up later.
i have since my previous post, modified my hardware and s/w for test purposes, to 4 wire spi. that works fine. i'm displaying stuff on the screen.

however i would like to use the parallel interface.
the only thing i can think of it that i have tied RES (high) and CS(low). i am not controlling those pins (lack of i/os at present). could that be the problem?
Title: Re: NHD-2.8-25664 OLED Display
Post by: Michael_L on September 11, 2014, 08:04:17 AM
Having the RES line pulled HIGH should be ok.  However, you will need to use the CS signal each time you write.  Ex: pull it low before the write cycle, and bring it back high after.
Title: Re: NHD-2.8-25664 OLED Display
Post by: riaz on September 12, 2014, 06:39:11 AM
i will give that a go, just as soon as i can, and will report back

many thanks