SparkFun Forums

[Pantheron]

I use the 16-Bit parallel Interface with intel-80 standard.
So, just for the moment i have only 64K colours, but thats enough.. I just wanted 1 transfer for colours in case of speed..
Just enough to have 2 for the position (so 3 transfers for 1 pixel if no framebuffer or something else is there)

For the touchscreen i used a MXB7846 from Maxim.

I think, till 24MHz core and 24Mhz peripheral its possible to get quite good performance, but at 60 Mhz its nicer

But!!!!
U should pay attention for a screensaver, the cmel oleds sucks in this case..
I got also a densitron that rocks!
There are some serious burn-out effects on the colours!

I will show some pictures too:

[silic0re]

That looks like fantastic work Pantheron, very well done. I'm also very glad to see that other folks have made successful use of these displays . It looks like we both have very similar projects, I'm also using an ARM on the board that I designed with the parallel interface. Out of curiosity what framerate would you say you can get, dumping a full framebuffer repeatedly? (or two alternate framebuffers, switching from first to second)? I seem to remember being able to get about 200 frames in around 8 seconds, but there looked to be some thrashing, perhaps since the data transfers aren't synchronized to any vsync signal?

If you don't mind my asking, it looks like you have *quite* a complicated power circuit on the right hand side of your board (CPU side, not screen side). What buck/boost/inverter did you end up using for the backlight?

[Pantheron]

Hi,

umm i dont really know how fast this could be, probably around 20-25 fps, depending on the arm you use.

I got around 45 but just dumping out into the ram. From flash its around 30.

The power circuit is an LT3471, i think a good solution, probably not easy to solder, but its okay. (In my case i changed this part, because the first didnt work, got a deep scratch on it, so it wouldnt work.. haha, but ok, now its working fine)

The others are a charge-pump for n-fets, a 3.3v ldo regulator and a ds2784 liion protector ic- with coloumb counter.

What are you doing with this oled?

I just use it to measure environment. Absoulte pressure, humidity and temperature. Just a oversized datalogger
I store them on the microsd, and can reload to show them on oled in a curve.

So long,

Pantheron

[inventore123]

Ok, after months of lack of spare time, I'm returning to these OLED displays, with some slow progress...
Here's the image of my NCP5810 breakout board


And here a close-up with a microscope of the chip

(no, that blob of solder isn't a short, those pins are meant to be connected together )

So next things to do is to solder the OLED connector breakout board, and to order the displays from vision-opto 8)

Just a couple of questions:
1) I have a small problem with the NCP5810: it generates the +4.6v positive voltage as expected, but the negative voltage is -5.4v, instead of -4.4v. This is because I used a 536k and a 56k resistors to generate the negative voltage, and the NCP5810 datasheet formulas say that with those resistors the output is -5.4v.
Curiously, the OLED datasheet says that it requires -4.4v, but it also has a schematic explaining how to connect the NCP5810, and in that schematic the resistors are 536 and 56k...
So I'm asking to those who used the NCP5810, what resistors have you used? the ones in the reference schematic, or have you tweaked the values to get -4.4v?
2) silic0re, which is the exact model of display you ordered from vision-opto? I'm looking for the C0280QGLH-T 2.8" with touchscreen, is this the one you're using?

[silic0re]

hi inventore123,

i've just checked my e-mail, and i think it was the "C0280QGLH-T" model that i've been using. i think all the models are very similar, except for some slight mechanical differences (like no metal casing, or different heights, etc) -- but that's just a guess .

best of luck!
silic0re

[inventore123]

New updates:
Soldered the connector breakout. Surprisingly the OLED connector is very easy to solder
Here's the image (as you can see from the big 40 pin connector, I opted for the parallel interface)


Also sent an email to vision-opto, now waiting a reply.

[mpanetta]

Would it not be possible to go cheap here and use a switched cap voltage inverter instead of a switching regulator to generate these voltages for the display? It would save $$ and definitely save space!

The datasheet I have does not spec currents on these pins, does anyone have any idea what they are? The all pixels on (white) condition and all off condition would be the most important numbers to have I believe.

Thanks,
Mike

[peter.stegemann]

New updates:
Soldered the connector breakout. Surprisingly the OLED connector is very easy to solder

Hm, this is exactly what I need in my current situation :-/ Ist there a way to get some of these breakout pcbs or maybe the layout?

[mgsqty]

Hello! gussy,
I also use zhe NCP5810,but it is very hot when it is working.And zhe voltage of -4.4V is low(-2.0V).
Please give me some help!Thank you!

[inventore123]

@mpanetta
The datasheets, even the official ones I got from vision-opto do not specify current on AR_VDD and AR_VSS pins.
The only data available is that the typical power consumption with 30% pixels ON is 350mW
I think only silic0re and Pantheron can answer this question, since they already have the display working.
Anyway, the NCP5810 is really small (even too small in my opinion), requires just a few tiny components, and I think has an higher efficiency tha switched caps at these current ratings.

@peter.stegemann
Well, I could post the gerbers, but first I'd like to try if the breakout really works

@mgsqty
Have you at least tried to solder the bottom pad? I placed a via under the package and soldered it, and hope it helps removing heat.
Is the negative voltage -2.0 even when the display isn't connected? Since resistor values for the divider are high, a bit of residual conductive flux might change the output voltage.

[inventore123]

Working! 8)

[inventore123]

Now the display is successfully displaying some non random data

(The original image is here: http://www.digitalblasphemy.com/fshow.s ... 2389445340)

Now, the image looks much better than the picture, and it's only at 16bit per pixel, and still without the gamma adjustment suggested. Really impressive

[silic0re]

That's really great work . Aren't they beautiful, once you get some digital blasphemy pictures on them? I was completely unprepared for how beautiful the displays are...

[inventore123]

True The image quality is excellent, and the viewing angle close to 180 degrees.
I already tried a PMOLED display (the sparkfun 128x128pixel), but AMOLED really is a great improvement.

[mpanetta]

Where did you guys get the connector, and which manufacturer did you end up using? I know the datasheet specs a Hirose connector, but at least one other company makes one that is compatible (Omron) and I am sure there are others.

It just seems like the $5.00 a piece DigiKey wants for them is a bit much...