OLED Building Signs

[mrp]

Hi All,

 

I keep seeing these really small OLED modules on AliBaba and wondering if they’re small enough to not look out of place on a layout.

 

So I finally grabbed a couple to experiment with, and today I got around to plugging one in and writing some code.

 

It doesn’t look too bad, and the scale works quite well.  The active area of the 128x64 pixel monochrome module is 21.7mm x 11.2mm - which converts to 3.2m x 1.7m in “real life”.

 

Here’s a couple of pics of it perched on top of the Kato “Boutique and Office Building” running a simple logo loop.  

 

 

 

I’ve also got a miniature color OLED to try out, but the wiring for that looks to be about 100 times more complex.

 

I’d say that OLEDs have probably become small enough to be useful.  And I guess with the “smart watch” fad kicking off, there’ll be a glut of *really* small hi-res displays available soon.

 

[railsquid]

Wow, nice.

[Densha]

This makes me think how cool it would be to implement this in N-scale: http://ja.wikipedia.org/wiki/%E7%99%BA%E8%BB%8A%E6%A8%99

Including small speakers for the announcements of course.

[cteno4]

Great stuff!

 

I had a couple of building signs out of small pvr devices, but those create the huge billboard signs and are tough to move the guts from the display as many are all on one board. Also the devices were all pretty crappy and don't last long. Also most use that stupid free mp4 encoding that much of the software I have does not go to well. those tiny oled are perfect for the smaller signs you see everywhere these days, but you have to have mrv's skills to make it happen!

 

I did play with using some little keychain digital picture fobs for doing something like a scheduling board. Some have a slide show function and you can just have some things change each time. Resolution was really crappy on them and again the displays are usually directly soldered to a bigger board. Plus its tough to not have auto turn off features and such plus usually require a few switch closures to make it start going. Just seeing what I could do with off the shelf stuff.

 

Mrv a simple solution would be a great seller! Just do a slide show of jpegs uploaded. May simple text pref file for timing and such.

 

The Oleds are getting very cool. I saw a control board with 3/4" square buttons all Oleds so it could be reconfigured with labels and icons on the buttons.

 

Cheers

 

Jeff

[katoftw]

Wow nice.  Having 100s in a street scene is perfect of a Japanese layout.

 

Link to product anyone?

Edited October 11, 2014 by katoftw

[railsquid]

Stupid question, but how are these programmed?

 

I'd love to have one on a city hall kind of building broadcasting public service messages with a satirical bent.

[mrp]

...how are these programmed?

 

 

 

For my testing, I hacked together some code that runs on a Microchip PIC24 microcontroller talking to the OLED module using I2C.  It seems that most OLED modules use a driver chip from Solomon Systech - so the command sets are all fairly similar.  Basically you just write bits at specific row/columns of the 128x64 bit display RAM.  Unfortunately, there’s no built in font or text display capability, so you need to handle character glyphs yourself.  I program the microcontroller in C using Microchip’s free MPLAB IDE and XC compiler.

 

If you wanted something a bit more plug-and-play, you could check out the Grove OLED Display running off an Arduino.  Here’s their web page with more information, a couple of pics, and some sample code.  I’ve never used an Arduino myself, so I can’t comment on how easy it is to get up and running, but their web page makes it sound pretty straight-forward.  Although even with that, you’d still need to write some code yourself to run on the Arduino and drive the display.

[railsquid]

Thanks. C coding I can handle (assembler as well should the need arise, though it's been a long time since I did any), but my knowledge of electronics is just about enough to wire up a DC layout... Looks like I never need to be bored again ;)

[The Next Station Is...]

If you check out sites like Adafruit or Sparkfun, you should be able to find similar small displays and the beauty of their products is that they'll have already written software libraries and tutorials for them for the Arduino, making it super-easy to set-up.

 

I'm a big fan of the Arduino and can recommend it for a way of getting back into programming and electronics without having to go in at the deep end.

 

As for building signs, I'd love to replicate the Studio Alta building outside Shinjuku station or something like that. I also like the idea of the station signs themselves; that would be fun putting up the trains and departure times, and controlling them!

[mrp]

Hi Densha,

 

Yes.  I initially thought that a display this size would look way too big mounted on a platform, and that the Kanji letters wouldn’t be very legible.  I thought you needed at least 18x18 pixels for Kanji - but after reading your comment I did some more investigating and I stumbled across a site with some 12x12 pixel CJK bitmap fonts.

 

Here’s the result:

 

 

I’m not sure if you can see from the video, but in real-life the size looks quite realistic - although it might be better to only show two lines of text.

 

Here’s a close-up.  The text is very clear.

 

 

I’ll definitely plan to incorporate some of these on my layout!

 

I like “The Next Station Is…”s idea of controlling the content to match what’s actually running.

Edited October 12, 2014 by mrp

[Densha]

Wow that's really awesome! Maybe there are some photos somewhere on the internet with real pictures of these kind of destination signs...

[mrp]

Hi Densha,

 

I looked at the Wikipedia page you suggested, and did a Google Image search for “発車標”, for ideas.

 

There are certainly some really nice looking information displays in real life, but the problem is how many characters you can fit across the 128x64 OLED.  And of course, it would look much nicer in colour.

 

For the experiment, I squeezed everything together as much as possible and just went with Time, Destination, Service Type and Platform - then chose a few random destinations.

 

Here’s a close-up:

 

 

I’m thinking that for hanging over platforms, a smaller two-line version like this one would look more realistic, so I may order a couple of those to try out - and try and make it look something like this:

 

 

We’ll probably need to wait for some type of miniature “Retina Display” full-colour OLED to do much better!

 

[cteno4]

Very cool mrp!

 

This was my problem when I played with the keychain digital photo fobs. They are 128x128 and about 24mm square. I experimented with a photo of a mid sized display board and put it at one end of the image. Of course you could not read the characters at ll, but the idea came across, especially if changed now and then. Then the idea was to use it in a situation where only part of the board would stick down and rest hidden in the ceiling. This does limit where you can use it. Biggest problem was the limited control of these cheap consumer fobs and I'm betting limited lifetime of them.

 

Jeff

[mrp]

Hi Jeff,

 

Yes, 128 pixels is just a few too few.

 

Fortunately, I much prefer the old retro look from 10 or 15 years ago:

 

compared to those new-fangled flashy LCD signs.

 

Probably because of all the countless late-nights sitting there staring up at those boards waiting for the last train - I guess I should add a 最終/Last entry at 00:13 and I’d feel right at home :-(

 

The smaller two line version I want to try is only 11.5mm high - with 5.6mm high active display area - so it may fit under the platform ceiling quite well, although I guess you have to wonder at what point does it get so small that you have to view it from just a couple of inches away to read it.

 

[Densha]

How do you actually control these displays? With a pc?

[kvp]

The cool examples above are controlled with a microchip pic microcontroller, a small one chip computer fully soldered together and programmed by mrp. There are different displays that are compatible with the easy to use ardiuno microcontroller board, a hobbyst mini computer, that comes assembled and only have to be programmed. The third option is to use an usb or serial port connected display, where you can send text and/or binary draw command from a pc and works like like an old serial teletype terminal. The fourth solution is a hdmi, lvds or usb connected display, which can be used as a small monitor and connected to any pc desktop as a secondary (or even primary) monitor. For someone not really into programming, i would suggest the usb connected displays that come with ready to use driver software and can show text or full screen images without writing programs. Unfortunately, these are somewhat larger than the oleds above.

 

ps: There are some really tiny 2 row monochrome oled strips mounted on flexible plastic, that are used on some cheap chinese mp3 players. The main problem is driving them, since they don't have any active logic on them and have to be driven externally. The general lack of english documentation is also a problem. (once i asked for documentation on a gsm board and the manufacturer said they only have chinese and simplified chinese, luckily it turned out to be a copy of a siemens product, so we used the siemens documentation)

Edited October 13, 2014 by kvp

[Martijn Meerts]

They're still a bit big for N-scale I think, even if you get a 2 line version. For H0 scale these would work really well.

 

It definitely does look good though. I wonder when we're going to get versions that are half the size and double the resolution ;)

[cteno4]

The little ones I saw a few years back at a trade show built into a 3/4" push button oled I think was 64x64. Quite crisp. It has a neat bus on the system so you could easily use a pc to control what was displayed on the buttons at any point. It was a bit pricy at the time, but was the first I saw out like that. Ir was a cool blend of having regular tactile buttons to use in an exhibit that you could relabel on the fly w.o resorting to touch screens which you can't blend with physical exhibit stuff well.

 

With little displays going int everything these days won't be surprised if they get smaller fast! I remember when Oleds were first being played with they were envisioning printing them on all sorts of stuff. Like packaging on products that would have a little active display on it. Or printing them into odd shapes as part of larger posters and such.

 

Jeff

[katoftw]

 

Hi Densha,

 

I looked at the Wikipedia page you suggested, and did a Google Image search for “発車標”, for ideas.

 

There are certainly some really nice looking information displays in real life, but the problem is how many characters you can fit across the 128x64 OLED.  And of course, it would look much nicer in colour.

 

For the experiment, I squeezed everything together as much as possible and just went with Time, Destination, Service Type and Platform - then chose a few random destinations.

 

Here’s a close-up:

 

 

I’m thinking that for hanging over platforms, a smaller two-line version like this one would look more realistic, so I may order a couple of those to try out - and try and make it look something like this:

 

chuo_board.jpg

 

We’ll probably need to wait for some type of miniature “Retina Display” full-colour OLED to do much better!

 

Since the OLED displays in blue/white.  Could see-though coloured films/vinyls be placed on the areas where you require green and orange displayed?

Edited October 14, 2014 by katoftw

[mrp]

Hi katoftw,

 

Good idea - I’ll have to look around for some suitable film to try - maybe some celophane or a small piece of lighting gel.

 

As an aside, I just read about these OLED Microdisplays they are developing for the new “wearable technology” fad.

 

Check this one out: Kopin CyberDisplay.  The smallest one is full-colour 428x240 with 0.20” diagonal.  At 1:150, that’s equivalent to 30”.  With that, you could model a normal-size TV.

 

It’s all a bit “bleeding edge” at the moment, but defintely this technology is advancing very quickly.

 

 

 

[mrp]

Hello again,

 

I managed to get the colour OLED display working and the results are quite encouraging.

 

 

Sorry about the video quality - it looks better in real life.  The colours are a lot more saturated and brighter than they appear in the video, and it doesn’t flicker.

 

Unfortunately the prototype PCB I made to drive the OLED is a bit large - plus the OLED itself is “pre-mounted” on a PCB as well - making the whole thing too unwieldy to easily mount anywhere.

 

 

I guess I need to think about a more compact design…

 

[cteno4]

Fantastic work mrp!

 

You could easily sell these!

 

Jeff

[JR 500系]

Fantastic work mrp!

 

You could easily sell these!

 

Jeff

 

Agreed Jeff!

 

And i'm looking to buy them! Especially the ones with the destination boards!

[kvp]

Looks nice! I would like to ask what is needed (bus, protocol, etc.) to drive a color oled panel like this?

[mrp]

Hi kvp,

 

Actually, I don’t think I chose a very good colour OLED to experiment with.

 

I’m using this one from AliBaba.

 

I bought it before doing any research into what was available.  It seems most OLED panels using Solomon Systech driver chips support both parallel and serial (SPI and/or I2C) interfaces, but the particular display I’m using only has parallel - which meant I had to make a fairly complex PCB:

 

 

Here’s the schematic if you’re interested.

 

oled_base.pdf

 

To find the protocol, I just did a Google search for the SSD1331 data sheet.  The protocol is very similar to the one for the Grove B&W OLED, so I guess all the driver chips from Solomon use the same basic set of commands.

 

Then I had to write some code for the animations and for mapping colours to the 16-bit RGB format the OLED uses internally.  I’m saving all the images as 4-bit grey-scale and then calculating colour palettes on the fly to save space on the PIC.

 

The OLED also displays full-colour images, but they really eat up the flash memory on the PIC.