E-ink Screen


WizardStan

Mega GP Mania
Joined
May 24, 2008
Messages
16,733
Why would you manually toggle a GPIO? Either use an i2c bus (which a lot of e-ink support) or set a serial port to the correct bitrate and let the hardware do everything for you.

edit: on second thought I can't actually find any to buy that are serial communication at all. There's some datasheets but nowhere seems to be selling them. The vast majority all have some kind of ribbon cable which would mean driving several gpio lines to it which would be very bad. Probably best to drop a $2 uC on there and write some firmware to drive the screen, and have it communicate via i2c with the main SoC.
 
Last edited by a moderator:

slaeshjag

¯\_(ツ)_/¯
Joined
Apr 8, 2010
Messages
2,687
Location
~Stockholm, Sweden
That's what I meant with a hardware interface. Not just "GPIO". When someone say "GPIO", I think about a dumb pin that you can set the voltage level on, not I²C or simlar interface :p
 

_wb_

Microbe
Staff member
Joined
Apr 5, 2012
Messages
5,390
Age
39
Location
Brussels, Belgium
Assuming that we can find a way to bring an image to the e-ink display, how much would it cost to get something you can read books on, with a refresh rate < 1s? How much would it cost to get a small low-res one with a real slow refresh rate, just good enough to display the date/time and maybe a song title? Can it be done without adding significant thickness or weakness?

Can someone bring some prices and specs to this discussion please?
 

WizardStan

Mega GP Mania
Joined
May 24, 2008
Messages
16,733

Kiga

Very Active Member
Joined
Dec 5, 2013
Messages
665
I think they are very cheap to produce but the price will depend on E-ink brand strategy to conquer smartphone world and how they view Pyra.

The fact Pyra isn't really a smartphone and that it is a small brand can help to have it cheaper. Also, there are others brand which produce different type of eink screen.

The only way to know it is to contact different brand which do eink screen, starting with E-ink.
 

pmprog

DNF (Did Not Finish)
Joined
Apr 25, 2011
Messages
4,099
^ In other words; too much :p
Depends - If you just wanted the little notification screen, $15 isn't too bad, but for a full book reading display, well, buy a nook - they're only about £25 :)
 

Kiga

Very Active Member
Joined
Dec 5, 2013
Messages
665
An e-ink screen would be a huge selling point. And it would make a considerable amount of extra promotion.
 

_wb_

Microbe
Staff member
Joined
Apr 5, 2012
Messages
5,390
Age
39
Location
Brussels, Belgium
I think a big e-ink screen is too expensive and would still be relatively small compared to normal e-readers. It makes more sense to just go out of the sunlight and use the actual screen. Or get a separate e-reader, those mass produced ones are probably cheaper than the extra price that would have to be added to the Pyra.

If a small e-ink display is cheap enough, then I think it would be a cool addition. If we can find one that is small enough, it could perhaps even be put somewhere in the front of the base instead of at the back of the lid. That way it can be viewed also when the lid is open -- e.g. to show subject lines of incoming mails while you're playing a game.

This one: http://www.digikey.com/product-detail/en/EK014AS014/EK014AS014-ND/4437987 is listed for $8.85 when you buy 100 or more. Maybe an even better price can be negotiated. It's 28.8mm high, so a bit too large to fit in the sides of the base (unless maybe the front side is not made vertical but at a slight angle such that the display is aimed towards the user).

Adding ~ $9 to the BOM could be feasible. It would be a nice extra gimmick, and fun to craft some pixel art for that 128x96 display.
 

DFP

Still Fresh
Joined
Aug 30, 2010
Messages
58
Don't know how I feel about another ribbon being squeezed into the hinge. Also, wouldn't it require its own display controller or add complexity to the board?
 

slaeshjag

¯\_(ツ)_/¯
Joined
Apr 8, 2010
Messages
2,687
Location
~Stockholm, Sweden
Depending on the display chosen, it is possible that it can be interfaced with a low-speed serial interface present on the SoC. In that case, the SoC can drive it directly.

Some E-ink displays do need an external driver chip though.

If something like I²C is used, you don't need any more wires on the ribbon. MIPI already has an I²C interface.
 

WizardStan

Mega GP Mania
Joined
May 24, 2008
Messages
16,733
If something like I²C is used, you don't need any more wires on the ribbon. MIPI already has an I²C interface.
Perfect. I hope it is included in the design, even if it doesn't get used for anything official, another hackable feature that will probably never be used but still might be one day.
 

mclien

Very Active Member
Joined
Mar 22, 2012
Messages
457
Location
Hannover
If I understood it correctly Shrps memory LCDs have nearly as low powerconsumption as the epaper Displays. The pepple has changed from epaper (prototypes and anounced for the kickstarter campaign) to memoryLCD (in production).

-plus it has backlite optioin by design

-plus it has serial interface (from what I understand, see below)

http://www.sharpmemorylcd.com/4-4-inch-memory-lcd.html

If we could get hands on one of these (no matter the size) and some of the somtware guys here can help, I'd like to try to build it into my old pandora...
 

WizardStan

Mega GP Mania
Joined
May 24, 2008
Messages
16,733
250 microwatt? Yeah, that's about 8 years of use off the Pandora's battery. I don't think we need to worry.

edit: unfortunately I can't find any suppliers of the 4.4" version, and double unfortunately the 2.7" version costs around $25-30. That's a little bit more than what the e-ink would probably be (scaling size, an approximation).

We'd have to find a supplier of the 4.4" to do a proper comparison.
 
Last edited by a moderator:

God Ginrai

Godmaster
Joined
Nov 27, 2005
Messages
5,466
Website
Visit site
It makes more sense to just go out of the sunlight and use the actual screen
 That's not an alternative, e-ink is better for your eyes because it is not shining light constantly into your eyes. (which is what LCD does)

EDIT: I'm looking on Alibaba and seeing tons of 6" e-ink displays for ~ $20-$25 per piece. I think we can find cheaper displays than the quoted $40-$45 ones.

-God Ginrai
 
Last edited by a moderator:
Top