hdmi input on a kindle(epaper)

[hdmi_epaper]

I Registered on mobileread.com
after reading good posts on kindle jailbreaking with serial to usb connection.

Members :
knc1
grant2

https://www.mobileread.com/forums/showthread.php?t=26754

Targetted devices are latest top tier models ereaders and these happen to be Kindle Voyage and Kindle Paperwhite 3.

The ereader market for anyone like me that wants to maximise the epaper beyond pdf/books(decent web browsing, external hdmi/mhl/DP... monitor) usage is very stagnant.

http://goodereader.com/blog/electron...amazon-or-kobo

Difficult to read article from goodereader on the subject of epaper innovation(or lack of it).

All ereaders use the same(and limited/dated on arrival) hardware with freescale CPU's 1GHz(1.2GHZ on Onyx Carta2 device) and 512MB DDR RAM.

Meanwhile tiny, powerful chips like the Qualcom 810/820 and Intel Core M
with excellent RAM specs are being fitted on tablets, PC Sticks and the like.
There never will be a native and meaningful android/windows/ios/mac or linux experience on an ereader(for those that value their vision and enjoy the greater outdoors) until eink and EPD controller board manufacturers are so limited in their focus - low powered devices.

Just to prove eink is not limited by nature to that please check this eink monitor showing animation on a USB Eink monitor(Dasung Paperlike 13.3")
https://youtu.be/ldBbVd0kBGE
https://youtu.be/QXF_5zxGkpE

Eink development boards via visconnect and digikey don't have the specs I talk about or the price point needed.

Dasung Paperlike monitor is still beholden by the same hardware and must be using a lower spec cpu Freescale i.mx6 at about 1GHz.

Kindles once rooted can have access to the entire OS.

The idea is to use a modern hdmi spec intel compute stick like dongle(gen 2 Core M reads good) that ouputs hdmi signal that is then hdmi received and
bandwidth reduced for partial updates etc
Kindle voyage / paperwhite 3 mod that lets them be used with any PC Stick really.
Here is a Freescale HDMI input enabled board
http://linuxgizmos.com/tiny-uav-orie...mi-in-and-out/

This is all sketchy so here are the
Good points :
Underlying OS is Linux/Android based
USB socket is already present on Kindles. So an HDMI out to a kindle USB "DIY GPU" adapter might be capable of delivering the grayscale bandwidth to the Kindle OS directly.
Kindle Touchscreen activity may be Kindle OS monitored and forwarded by USB/Bluetooth to the PC Stick OS(some Windows 10/Android mouse drivers might be needed)

All this is to be done on the Kindle's 1Ghz CPU and 512RAM.
Making a mod to turn a Kindle to a responsive touchscreen monitor would require a good "hdmi input from PC Stick to Kindle USB- output" diy device. The device would scale the hdmi stream down to grayscale and compare for screen regions that have changed and need to be updated on the kindle.
Lots of energy wasted on scaling down from HDMI input but with Dasung Paperlike asking $995 for essentially grayscale eink USB monitor that's near impossible to buy.....

Ultimately a tiled display wall of kindles is what I am after

[knc1]

Is there a question in that post?

[hdmi_epaper]

Originally Posted by knc1

Is there a question in that post?

Leverage on your experience with hacking Kindles, is it possible to convert hdmi signal fast enough to then be passed to the kindle OS(usb I presume)?
Is it possible to export through a cable the Kindle touchscreen events to an external PC?
Since the Fire OS is linux/android can the touchscreen driver be used on an external Ubuntu system?

Checking my knowledge, Freescale i.MX series includes an EPD controller,
Is it possible to get a Qualcom 810/820 dev board or Core M dev board run along
a discrete EPD controller to drive the Voyage / Paperwhite 3 eink display.

[eschwartz]

There are a few resources around for using Kindles as an E-Ink monitor.

e.g. KindleVNCviewer: https://www.mobileread.com/forums/sho...d.php?t=150434
Or it's rework/successor, kvncviewer: https://www.mobileread.com/forums/sho...d.php?t=228167

[knc1]

And there is the (faster) non-vnc solution that Idoit was working on with someone else here.

Geekmaster was going to build a "Kindle Wall" out of a bunch (64?) of Kindles. I don't know if he ever completed that project.
(It is only mentioned here in passing, not documented here.)

But K4-Diags and all of the 5 series devices run X11, which can do video wall displays. Although the wall display feature is unlikely to be built into the firmware from the factory.

There is also a discussion here about using the 13.3 inch, e-paper screen.
I don't recall what became of that discussion thread.

# 88 33

[hdmi_epaper]

Originally Posted by knc1

And there is the (faster) non-vnc solution that Idoit was working on with someone else here.

Geekmaster was going to build a "Kindle Wall" out of a bunch (64?) of Kindles. I don't know if he ever completed that project.
(It is only mentioned here in passing, not documented here.)

But K4-Diags and all of the 5 series devices run X11, which can do video wall displays. Although the wall display feature is unlikely to be built into the firmware from the factory.

There is also a discussion here about using the 13.3 inch, e-paper screen.
I don't recall what became of that discussion thread.

# 88 33

I did some research.

It can't be any faster then adding an hdmi port on anything Freescale i.MX based.

i.mx6SL Freescale(and the yet to be released i.mx7 dual core) as is used in all the current crop ereaders allows for a camera input stream through the MIPI CSI interface.
Then there is the HDMI to MIPI CSI Toshiba line of chips( http://toshiba.semicon-storage.com/u...idge/hdmi.html ) that cost $5.00 from what I read and can
convert the HDMI signal to the existing input interfaces on the i.MX ereader hardware....

What would it take to simply add the chip neatly on a device like Paperwhite 3 or Voyager with the 300dpi Carta display?

I presume some drivers that can scale down and grayscale the hdmi stream would be needed.

Now would the EPD controller take care of partial screen refresh efficiently? Most hdmi signal will be static images so won't need to constant updates of the full eink screen.

Enlighten please.

I mean if this pans out you can simply run Android Lollipop/Marshmallow apps by slapping a good smartphone to the back of your ereader and hdmi cable connection.

[knc1]

Originally Posted by hdmi_epaper

I did some research.

It can't be any faster then adding an hdmi port on anything Freescale i.MX based.
- - - - -

But it can be a whole lot cheaper than customized hardware additions.

Hardware additions such as you propose are just not practical.

I think you need to continue your research -
Buy one, take it apart, then consider what you will do to it.

[inedible]

On a fast wifi (or USB networking) connection, VNC is fast enough. I think the eink display is the bottleneck here. I think it takes something like 80ms to refresh the eink. VNC is faster than that.

As far as decoding HDMI, forget it. Doing it in software, in realtime, using generalized CPUs would take many many many gigahertz. You'd have to capture the stream, analyse it, decode it, etc. Even with the oldest and most primitive HDMI1.0 spec, you're looking at 165MHz of compressed datastream that has to be captured and processed.

They make specialized chips for that. FPGAs and the like that do this a thousand times more efficiently than a general-purpose CPU. You could buy one, figure out how to build a breakout board for it, try and attach it to some bus in the kindle, write drivers for it and compile a new kernel for the kindle, or you could simply take something that already has HDMI input, and run a VNC server on it.

[hdmi_epaper]

Originally Posted by knc1

But it can be a whole lot cheaper than customized hardware additions.

Hardware additions such as you propose are just not practical.

I think you need to continue your research -
Buy one, take it apart, then consider what you will do to it.

Still waiting on : Jim's Board to arrive. Taking the kindle apart was fairly easy.
There does come a point when adding custom hardware additions takes back stage to a full scale custom board design...

Toradex and boundary devices have I.mx based development boards. I.mx7 is not out yet(which is why new device releases is sluggish atm).
The I.mx based products from the above companies confirmed that
'You can input HDMI and it does "act" like a camera in the Linux kernel"
Unfortunately they also said that the EPD controller part of the I.mx chip is not exposed for interfacing on their products .

[hdmi_epaper]

Originally Posted by inedible

On a fast wifi (or USB networking) connection, VNC is fast enough. I think the eink display is the bottleneck here. I think it takes something like 80ms to refresh the eink. VNC is faster than that.

As far as decoding HDMI, forget it. Doing it in software, in realtime, using generalized CPUs would take many many many gigahertz. You'd have to capture the stream, analyse it, decode it, etc. Even with the oldest and most primitive HDMI1.0 spec, you're looking at 165MHz of compressed datastream that has to be captured and processed.

They make specialized chips for that. FPGAs and the like that do this a thousand times more efficiently than a general-purpose CPU. You could buy one, figure out how to build a breakout board for it, try and attach it to some bus in the kindle, write drivers for it and compile a new kernel for the kindle, or you could simply take something that already has HDMI input, and run a VNC server on it.

VNC option has its uses and offers some advantages.
When it comes to the eink screen speeds I believe your estimate is not far off from what is currently believe to be an inherent limit of the epaper tech at the moment.
There are also two examples that made me scratch my head though,
https://youtu.be/ldBbVd0kBGE
https://youtu.be/QXF_5zxGkp
The use epaper monitor is a recent enough example(new batch allegedly being shipped in March 2016). While I don't know the precise EPD controller(might be a batch of I.mx7 duo they somehow got hold of ahead of everyone else, the old I.mx6 sololight or something else entirely). The eink screen used in the product as published on their website has a resolution of 1600x1200 on a 13.3" screen and suggests to me that it's the same eink panel that Sony's digital paper DPT-s1 uses.
The other demo is Epson controller based circa 2013 at most and is a fine example that maybe eink screens can be a bit more responsive than what is currently being offered. Question stays open on whether the I.mx6sl as used in all current ereaders is underpowered and exactly how much latency of the screen can be attributed to that.

Here is something that the VNC option can't take advantage of on all ereaders hardware - the present and fairly old I.mx6 provides a mipi dsi and mipi CSI plus a few other interfaces....In other words going the extra mile by doing custom hardware addition on an existing ereader should allow for an extra hdmi out, hdmi in and camera input...
I.mx7 which has a new EPD controller built in too is a good candidate to go the extra mile...

I mean some people on this forum have long gone beyond simple software tinkering...rooting the kindle after all requires soldering wires, Jims usb dongle ...