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Author Topic: Outdoor display 3-5" OLED or something else?  (Read 1152 times)
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Bavaria
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Hello,

I am still struggling with my decision for a display for my ebike computer.
I've bought a 20x4 character LCD display, but I think I would prefer a graphic display that has good readabiliy outside.
OLED might be the way to go, but I can't find one large enough.
Do you guys have any suggestions?
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Israel
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I think that a black-on-green (or gray) like in simple digital watches would probably give you the best results visibility wise.
There are plenty of graphic LCDs out there.
What kind of resolution do you need?
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Bavaria
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Well, I would like the resolution as good as possible, but 4 lines for text would be enough.

This is the information I would like to display:

24,5 km/h
100 rpm 
48.1V
20:30
2.15 Ah 
20.3A   
23.30km
67:23
32.1Wh   
250 W
5.2Wh/km
43.2°C
17.3°C

The speed and power may be a little larger in the middle than the other values, but the rest can be in 3 rows around the speed value.
So, I'm guessing 240x128 would be enough
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NSW Australia
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The limitation of OLEDs is that they are using power to compete with the natural - sunlight.

If you drive them hard enough to be visible under all conditions, you will be using a lot of power in a mobile application.  That's why most if not all cyclocomputers still use LCDs.  (I suppose some may have an optional backlight - but I haven't looked into it.)
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Bavaria
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Well, I do have a ebike battery that I recharge every day, so the power consumption of the OLED is a non issue.
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NYC
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Even good OLED might be blinded by the sun.

I suggest pure reflective LCD. Same 1604 of whatever. Look for "black on white". They will be nicely visible in direct sun light even without backlight.

I'm using 5110 LCD without backlight - very usable.
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Bavaria
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I have a 5110 display here, and if it were 6 times bigger, I'd go with it.
But on the handlebar while riding it needs to be bigger to display all the info in a readable size.
If the displays aren't too expensive I wouldn't mind trying a couple of different ones. I bought the blue 20x4 displays aswell and I have a 16x2 I think in green, too.
So, for the prototype I don't mind trying a few different things in hopes I can duplicate them for other bikes later and other people won't have to go through trying everything, too
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NYC
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Another wild idea:
Do you recall Sony's earlier Mavica cams? They had narrow lens on top to collect sunlight to use as backlight. I had one. Even in bright sunlight they are clearly visible, though a bit darker than perfect, never the less, pretty bright, brighter than backlight can do. Not transflective, regular RGB LCD.
See some Wikipedia's pictures. Clear line right above the LCD is backlight collecting lens.

So get one of those 3"-ers, reap back and fashion something Mavica style. Maybe Fresnel lens+mirror or lightguide + difuser (probably can use display's own).

(side thought - why they don't do Mavica backlight on other cameras now? Patent got to be expired by now!? It is way older than 12 years!)
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Bavaria
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Thanks for the suggestion, but that would be way too much work to duplicate a few times. It should be viable to have 5 or 10 of those in the long run.
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Israel
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I think your best bet is a black-on-green or black-on-white/gray LCD, most of them include a LED backlight for dark conditions and will be very easily visible in daylight. If you can fit all of your data in a 20x4 character configuration, these LCDs are great, very cheap, easy to work with and consume very little power which is always good. They are usually about 3" diagonally. There are 40x4 LCDs, they are bigger and considerably more expensive than the 20x4 ones, but can fit a lot more data. Consider the following: These 20x4 text displays are equivalent to a 128x32 graphic display in resolution (per pixel). A 240x64 graphic display would probably have enough space for everything you'd like to display.
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Already mentioned above: Pure reflective displays are very well suited for outdoor use. There should be at least one variant for each type of the EA DOG series of displays, which is availalble as reflective version.

But small note: As far as i know there is no Arduino lib available for the UC1611 controller.

Oliver
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Bavaria
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I had already asked for a price on the DOG display. They're over 150€ a piece :-(
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I had already asked for a price on the DOG display. They're over 150€ a piece :-(

Which one?
The DOGS102 white reflective should be less than 10€. Ok, could be too small.

Another option could be this (or different color)
http://www.buy-display.com/default/cog-display.html
Some of them are claimed to be sunlight readable (see datasheet).

I ordered one of these displays and hope to add support for u8glib soon.
Shipping will cost extra $7. Also production will take 1 week and shipping probably another 2 weeks. At least they did not reached me until now (two weeks since my order was placed).

Oliver



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Bavaria
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Thanks for that link.
I'll make sure to buy from there. Maybe we can order together next time. I'm from Germany, too.

Do I need any additional controller for that display?
Is there some sort of a mounting frame for that particular one?

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I hope that the display can be directly connected to the Arduino. The display has a controller included, but i have not analysed it. I assume the controller has its own frame buffer memory, so it should not be an issue to use it with an 8 Bit controller.

It seems that buy-display does not sell any frames.

Grüße aus BW
Oliver
« Last Edit: September 15, 2013, 02:13:34 pm by olikraus » Logged

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