Pervasive e-Paper Displays

If they were just not wanting small customers they would simply put the datasheet online. The industry is closing up, there are a few big players with access to everything - those making PC-s and phones - and the rest of us are supposed to die out. Which eventually will happen of course but they seem too hasty about it IMO, perhaps still not certain enough about their position - no matter how rock solid it may seem from outside.

Dimiter

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There will always be the smaller buyers of any good. Cell phones and watches aren't the only place where displays will be used and 4.4 to 10 inch displays will never be in those products. Further, they are doing just fine with standard temperature displays. Heck, if that is the only market they were going for, they would require me to sign an agreement to buy a million dollars worth of goods like TI asked me to do once.

So clearly they want to sell these displays. I just don't get their methods.

One thing I didn't mention is that their new line coming out will include the display controller on the display. But that won't be the wide temperature. So that still doesn't explain their reluctance to fully support these displays for the masses. There are even two, count 'em *two* Kickstarter campaigns for their smaller displays which don't require the separate controller chip. I'm pretty sure these guys are getting support from Pervasive.

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Rick

Who knows, we can only speculate of course. Perhaps they have to sell the display itself too cheap to be competitive and hope to make up by adding the price of the controller (not sure at all this is a possible scenario). But display controllers are extinct on the market so may be this is it. Or may be there are some technical details not speaking well about them and they do not want to show them... Anybody's guess.

Dimiter

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How do you mean display controllers are extinct? Or do you mean separate display controllers? Or maybe you are saying the controller is typically built into the CPU?

One of the things I have given thought to for these displays is to do a daughter board for the BBB or rPi. A small FPGA would be ideal and there are a few that would be very low power too. The BBB has several size displays available up to 7 inches, but not e-paper.

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Rick

I mean both, it is impossible to get a PCI/PCIe display controller nowadays to just use. You have to build it yourself - FPGA or whatever. I am considering certain choices (vaguely, have not started real work on it but I guess I'll have to design yet another display controller, last time the b69030 just did the job for me and saved me the effort. But I have lost count of the display controllers I have designed over the past 30 years so one more won't make much of a difference).

Well yes, nowadays things with a display are much easier to find. My current flagship product uses exactly that, has all it takes on board except for a display - and a PC or tablet etc. is used to access it via VNC over the net (pixels moved over Ethernet rather than over the VGA cable :-) ). But apparently your e-paper requirement does not make it easy, if it is so hard to get data on how to drive a display module (I have never used one, just "normal" TFT etc.). Perhaps you can look around for similar sorts of displays and get a feeling how it is done, may still be doable with some (or some more...) guesswork.

Dimiter

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Yeah, others have suggested the reverse engineering approach. I could just buy their unit and copy it's functionality. If I am going to offer a product I want to be able to say that it meets design criteria. If I am operating the display contrary to the maker's instructions (not using their controller) I won't feel comfortable with that.

I'm still in dialog with the Pervasive contact. I'm willing to use their controller board if it can do the temperatures. If it can't, they need to explain what gives. The only controller solution they support doesn't meet the same temperature spec as the display? Heck, it doesn't

cold, but I'm not going to build in a refrigeration unit.

BTW, why is it *re*frigeration rather than just frigeration? Is the idea that this is getting cold again? lol

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Rick

May be they are still trying things out - or rather have the guy who designed the controller try things out and make it work over temp. Beats me how they can make a display module and not a controller to match its not that wide temp range but there you go... Much of it might boil down to the "click and expect" generation taking over, what do we know. There was no option for this temp range on the drop down menu... :D.

And then we still say "fridge" - go figure. Perhaps the "re" comes from the market introduction days, people have bought frozen things and could then re-frigerate them, lol, my chances to guess that are worse than these of a native English speaker.

Dimiter

We are talking about two different types of displays. e-paper is virtually static display only. Even at room temperature the updates take on the order of a second rather than frames per second. In colder temps it ranges up to nearly 5 seconds. So PCIe is not even in the picture. SPI is the appropriate interface.

When I talk about controllers I am referring to something like the Hitachi chips that are so popular with the two or four line alphanumeric displays. I don't know if there is a graphic equivalent, but this is just a way to get the data to the display without much complication.

I did find a similar technology called electrowetting (EWD) which can update fast enough for video and can be either front lit or back lit. Front lit includes room lighting like other e-paper displays. It is also a color technology. I can't find if it is bi-stable or not.

Then there is one that uses MEMS which is similar and is bi-stable... I think. Hard to keep it all in my head. Neither one is quite ready for prime time. Not sure what is holding back Liquavista's EWD displays, but I think I read they aren't going to make displays anymore, but are planning to license the technology. The MEMS technology currently uses multiple elements to get color and they are working on a new version that yields different colors from each element, so one element per pixel. I think the MEMS was the one that I read was designed into some product but they couldn't get the yield high enough to actually produce them. Maybe in another year or two.

I don't really have a clue. As you say it's a more narrow temp range than even commercial which nearly *all* ICs will meet. They list three

smallest display either, so I don't get it at all.

I know where "fridge" comes from, short for the brand name Frigidaire. You know, frigid - air. Besides, Refrigidaire sounds pretty goofy. lol

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Rick

Not sure what you mean here but there are several FPGA boards for both the Rpi and the BBB, and several e-paper boards too (search on adafruit.com for example). The biggest is 2.8" or something like that. I'd sure like having a bigger one, like a Kindle.

2.7 inches I believe and that is pretty durn small. The one I wish to use in a product is 4.4 inches but none are very high resolution. The 4.4 inch display is only 400x300, but good enough for my product idea.

If you want an epaper display, there is a 6 inch display from Good Display that is 800x600 I believe. I see it on Alibaba a lot. Not sure if it needs anything special to drive it. It even has optional touch

good to me. I can get you a part number if you want.

Pervasive has their new 4 inch display coming out with the integrated controller. I think it is 400 by a bit under 300. Can be directly controlled via SPI and maybe a couple of GPIOs for the misc stuff like power down.

I haven't seen anything else that is commonly available with info on using it. Alibaba and some other middleman sites have displays for various eReaders, but no info on using them.

ePaper is definitely available for use, but not a lot of options and not very good support. I guess they still wish to cater to the big customers who they will hand hold.

BTW, I just want to remind you that epaper is only low power when you don't update the display. An update uses a fair bit of power. Nothing insane, but far from microamps.

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Rick

4.4 inches is phone sized, I guess. I assume you've got some application for your customer but I've been sort of wondering what to do with such a thing (I was actually thinking of the 2 inch ones) as a generic product. Outdoor box with BBB inside and display on the front. I keep thinking a regular small reflective LCD would work about as well. Most stuff to display either would be just a little bit of data (temperature and stuff, works fine on a 2 line display) or would be completely static (could be printed on a card). Higher volume info could be presented to a phone, since the person might want to save it anyway. You've probably thought of uses I haven't though.

Hmm, that's good to know. I know that some old versions of the Barnes & Noble Nook (Kindle competitor) ran Android under the covers, and were jail-breakable, so if I just wanted to mess with an epaper reader it might be easiest to get one of those.

Quick web search found this and similar:

They also have some smaller and bigger (8 inch) ones.

Hmm, how about this:

May 21, 2013 ... E Ink Holdings... today announced the upcoming release of E Ink Aurora, a first-of-its-kind electronic paper display (EPD) able to withstand freezer's temperatures.... Providing low power usage and cost optimization through a 5-volt driving capability, Aurora supports applications in conditions as cold as -25 C.

And here's some control chips:

Yeah I know about that. The very slow update rate is also not so nice.

There used to be laptops with reflective monochrome lcd's, some of which were pretty good--highly readable indoors and out. But they don't seem to make them any more.

The Pixel Qi display (color, reflective, backlit) might be of interest.

Why epaper if you don't mind my asking? Just cause it's cool?

Reflective doesn't work very well in dim lighting. ePaper works over a much wider illumination range. LCD also is only rated to freezing without heating.

My initial target is commercial, weatherproof box, hamfist buttons, no touch screen.

I expect that is the same one I am referring to. Other than the ones literally made for eReaders, these two are the only makers I found.

Aurora is the display technology and Pervasive is the only company selling them to the general public. Digikey has them.

Does Epson say they work with the Pervasive Aurora displays? Pervasive doesn't. The three larger Aurora displays are different from the smaller ones. The small ones have an SPI port and a few discrete controls. It appears that the entire controller is inside. The larger displays have the same interfaces, but it seems that is not enough as they also require a separate controller. The 7 and 10 inch displays have two connectors which makes me think they have two sections, separately controlled. Mpicosys makes the external controller. Maybe Epson makes the internal controller.

I've read some reports of new reflective displays, but I haven't seen anything I can buy.

Anyone actually selling them? Most of the new technologies are talked about and may appear in an eReader or tablet, but you and I can't get them.

High visibility and wide temperature range. Otherwise I need to go with OLED or possibly EL (at a very high power consumption). I don't think I have found a graphic OLED display, just alphanumeric. I'd like something around 5 inches but has to work in the outdoor temp range.

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Rick

I think I have cracked the code with Pervasive Displays. Seems they have gone to a fair amount of trouble to develop and promote an e-paper

Heck, this controller even limits the temperature range of the

I suppose if your use case is to update price labels in a refrigerator/freezer periodically and the display controller is in the updating unit which does not spend much time in the cooler, this will work. For any outdoor usage this is pointless. It was only now that I realized why this pairing was made.

The last response from Pervasive on this matter seems to be saying they are contractually obligated to only sell and support the Mpicosys controller for their 4.41, 7 and 10 inch displays in both standard and wide temperature ranges. It's a durn shame. I guess the marketeers felt this was a workable approach. They clearly don't see usage other than retail price signs to be much of a market. Maybe they need to watch Warehouse 13. It gets pretty cold in the Dakotas doesn't it?

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Rick

For anyone interested I've obtained another data point. I heard back from Mpicosys, the maker of the controller. They say the PDI spec on the display "changed" after they produced their controller and so they have never updated the data sheet. I guess that means they designed their controller for the standard temp display and now PDI is using it for the extended temperature range. Oddly enough they say there is a

Not sure why this would happen. They say the contrast will drop

I have to assume the extended temperature range of the Aurora e-Ink displays was an afterthought where they realized it could be done by slightly modifying the spec or a very minor mod to the production process. Mpicosys had already completed their controller design and has not made any updates to accommodate this wider temperature range. The market is not especially large so neither party is putting much effort into it.

Maybe OLEDs are looking good. lol

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Rick

I've been working on a project recently with Pervasive Displays EInk displa ys. Their smaller screens are easy to use as there are many libraries out t here to help interface with them. However, our team needed to use 4.41" scr eens and were unable to find adequate drivers for it.

I have just released a very early driver for it open sourced here:

I would love to get additional members contributing to it and making it bet ter.

Let me know what you think!

Hi, it's great that you released a driver. Exactly what hardware does this work with? The 4.41" Pervasive display I found requires a hardware timing controller. I wanted to use the display in extended temperatures (outdoors) and the timing controller is not really rated for this.

What is your app?

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Rick