The plausibility of an E-Ink Display

[JustSimon]

A friend of mine has a really nice e-reader that makes reading e-books very comfortable.
I've used it in the past and since then want to get one as well.
Today I saw such a display driven by a Raspberry Pi and thought about the possibility to make it an external (or if my dearest dreams come true, an internal replacement) display for my future Pyra.
I've seen a few displays online for sale that include display drivers and are quite cheap.
I just don't have the technical knowledge to determine if something like this is possible.

Looking forward to your ideas
Simon

 

[Binky]

As far as I know, the Pyra's display is controlled over a MIPI-DSI connection, which is pretty common for small/portable electronics. I'm fairly confident you could find an eink display which would accept the same signals - but you might run into problems with framerate. Not much FOSS is designed with eink in mind.

Apart from that, there's always the HDMI output on the back, which should work much like any other.

 

[JustSimon]

I'm looking at specs of e-ink displays right now...
What kind of Interface does the Pyra have for it's display?
I've seen displays with:
- I²C
- Serial
- RS-232
- SPI

Is one if them compatible with the Pyra?

If not, I'm gonna start looking at display drivers that use USB and/or hdmi

 

[slaeshjag]

None of those are display interfaces per se. There is I²C available inside the lid. I²C is unsuitable for anything but low-resolution displays that are updated infrequently.

 

[JustSimon]

I²C is unsuitable for anything but low-resolution displays that are updated infrequently.

Well, e-ink displays only have a rather low update rate, so that would fit...
I could also imagine 3D-printing a lid that is a bit thicker and has an e-ink display for reading e-books and displaying status/time/other info...

That would look pretty cool...

I've found this one, which although not being very cheap (57 Euro) is very thin and has red as an additional color.
https://www.digikey.com/product-detail/en/pervasive-displays/E2417ES053/E2417ES053-ND/6211106

 

[Binky]

What kind of Interface does the Pyra have for it's display?

As far as I know, the Pyra's display is controlled over a MIPI-DSI connection

As slaeshjag says, the interfaces you mentioned are general-purpose, low-datarate affairs that aren't really suitable for high-resolution graphics - though I daresay something could be made to work...

 

[Grench]

Maybe have a stand alone minimal eink display that feeds off of bluetooth? A driver would have to be built. I have a 3" BT display from a crowdfunding, but driver support was nill.

Oaxis was the company.

 

[Rami]

One Spectra E-Ink, the Red Black and White e-ink display on the back of the lid of a red Pyra would be awesome!

It could mimic almost exactely layout of the back (black badge in a white/translucid logo) and also be used as a e-reader. That would be an great project to make.

 

[kabaiakh]

I really like this idea, just like the Yota phone. :=)))
Good for clock, weather, notifications, decoration (a red pulsing logo would be great), as well as book reading.
The lid part should be kludgy moddable to host this second screen.
Not sure about wiring to the the main board through the hinge though ...

 

[spud42]

Well, e-ink displays only have a rather low update rate, so that would fit...
I could also imagine 3D-printing a lid that is a bit thicker and has an e-ink display for reading e-books and displaying status/time/other info...

That would look pretty cool...

I've found this one, which although not being very cheap (57 Euro) is very thin and has red as an additional color.
https://www.digikey.com/product-detail/en/pervasive-displays/E2417ES053/E2417ES053-ND/6211106

that display is only 400x300. most eInk readers use 800x600 or better screens like the 6"kindles,kobo's etc. i just bought an ereader from gumtree( sort of like craigs list) for $30AUD so while an interesting idea and technically possible i dont think its economically feasible.

 

[sepulep]

you can drive some ereaders (from pocketbook, but maybe also others) as external display):
https://github.com/borzunov/remoteink

maybe someone can compile this for pandora & eventually pyra?

 

[mclien]

I own this reader: http://the-digital-reader.com/2013/01/24/review-hands-on-with-the-worlds-smallest-ereader/
it has a 4,3" display with 800x600 res.
Holding that one instantly made me think of making a PalmPyra. Design a new Mainboard tat fits into those old PalmIII cases with a e-ink Display. Use it for textbased applications ( reading, appointments, contacts, maybe e-mail). Attach those old foldable keyboards to it etc.
hide the connectors inside the old battery bay to connect it as an desktop at home (via HDMI)

 

[JustSimon]

Does anyone know what the displayboard is actually capable of and what could be connected to it?
Sadly the Pyra Wiki is lacking a lot in technical specifications.
[doublepost=1494853884,1494853390][/doublepost]@mclien Wow, that is a really nice device!
Sadly it doesn't seem to be available anymore.
Otherwise I'd get one to dismantle and see how hard it would be to integrate into (or onto) a pyra case.

 

[levi]

I think the display board basically just splits out the LCD data and the touchscreen data from the cable that goes through the hinge - you need to connect the two different cables from the LCD/touchscreen assembly and the one cable running from the main PCBs.

 

[Rolf van Kleef]

There are 5 I²C busses on the Pyra, of which 4 are accessible. These are "Sensor", "System", "Peripheral" and "Panel". Each of these 4 accessible busses run at 400KHz, meaning you can get a theoretical bitrate of 350 kilobits/second through each of the busses.

"Panel": TouchScreen, LEDDriver
"Peripheral": Joystick, Joystick, Power manager
"System": SMBus, I/O expander, LEDDriver, AUDIO contact sense
"Sensor" : Gyroscope, Compass

The challenge now is to find the least-congested bus, which is likely either "Panel" or "Sensor".

 

[JustSimon]

I am currently contacting the manufacturer of this display and looking for datasheets.

https://www.aliexpress.com/item/2-9...Screen-296-128-I2C-Interface/32426423928.html

If anyone finds I2C E-Ink displays, posting them here will be appreciated.

 

[Rolf van Kleef]

I am currently contacting the manufacturer of this display and looking for datasheets.

If anyone finds I2C E-Ink displays, posting them here will be appreciated.

Also, in case someone finds information like datasheets on this display, that would be much appreciated.
[doublepost=1494883698,1494882341][/doublepost]You can refer to: pyra-handheld (dot) com/wiki/index.php?title=Mainboard for more information about the I²C bus.

 

[Grench]

I have always liked the concept of replacing the lid cover with an e-ink screen. It's so much of a niche of a niche though that I doubt it would make production sense. It might be better to start with a stand-alone e-ink reader/display like the Oaxis one and then figure out how to have the Pyra communicate with it? Yes, two devices, but that Oaxis unit I got from their crowdfunding was very thin & light. If only the software integration were better - it only worked with a handful of applications. It never was able to actually display the home screen on Android. Cool piece of kit though.

 

[JustSimon]

I'm planning to build this myself when the Pyra is out and 3D-Print a case and solder the display to the display to the sceen myself.
I'm posting this here for two reasons:
1. I will probably make mistakes and/or need help in general.
2. I think this is pretty cool and others might be interested in modding their device jn the same way.

And I would like to have only one device. Even if the Eink screen turns out to be too small for use as a proper reader. I just like the idea of a second screen. And in the wrost case, it's gonna be a nice clock/notification list/newsfeed/mp3-player-info-display.

 

[levi]

You can refer to: pyra-handheld (dot) com/wiki/index.php?title=Mainboard for more information about the I²C bus.

Thanks for updating that! I'd forgotten what we lost if we went for a standard (non-cellular) version, and that explains that it's the thermo-, baro- and hygrometers (and GPS I think). They keep the compass, accelerometers and gyroscope, meaning they can all be used by software regardless of the model.