Update eink waveform

[Nephiel]

Originally Posted by dsmid

I've done a little research and found this:

• Various waveforms are stored in /opt/eink/images/ in *.wbf files.
• Helper links to these files (named after waveform versions) are in /var/local/eink/.
• If file /var/local/eink/dont_update is present, the waveform won't be flashed. Ever.
• If file /var/local/eink/update_flash is present, the waveform will be flashed and then the file will be removed.

So all it takes to stop flashing the waveform is to create file /var/local/eink/dont_update . Easy peasy.
I can create a launchpad .ini file if someone's interested.

But we do want to update, right? To flash a working waveform into a replacement e-ink panel...

The update_flash file, on the other hand, might be useful (and dangerous) if it allowed any .wbf to be flashed without checking panel ID.

[Supra James]

Originally Posted by Nephiel

Hi there. I just managed to copy the waveform from a broken panel into a new one!
This thread has provided me with very valuable info so I thought I'd share the process here.

Brilliant work mate.

OK, dumb question time - but now you've dumped a panel's EEPROM, can we use that file in conduction with the ENABLE_DIAGS menu to flash it to a new panel without getting the arduinos out? Or is the .wfb file format different to the raw EEPROM dump?

[Nephiel]

Looks like the EEPROM contains a little more data than just the waveform, such as "Panel ID", "VCOM setting" (which seems to match the sticker on the ribbon right opposite the EEPROM chip), and who knows what else. And I don't know what the .wbf files actually contain. The ones on /var/local/eink range in size from 46KB to 94KB, while the EEPROM has a maximum capacity of 256KB. That's why I made available the dumps I have - hopefully someone can make sense of those.

Anyway, the Kindle won't allow flashing just any .wbf through the ENABLE_DIAGS menu, the panel IDs have to match.

[zxczxc]

would inverting the screen (white on black etc), be related to something like this?

[Nephiel]

I don't think so... I have found very little info about e-ink waveforms. Even if it were possible to invert the screen by flashing a .wbf file (or the entire EEPROM), we would still require the tools to calibrate the e-ink panel and create said file (or EEPROM image).

IMHO it would be easier to invert the screen by software or firmware hacks.

[zxczxc]

ooh, i must have not understood exactly how the eink waveform thing worked then, i didn't realize this fix was that low level thanks

[Don1234]

tccsargent, your a genius. cheers works great now.

[slashguitar]

Originally Posted by dsmid

I've done a little research and found this:

• Various waveforms are stored in /opt/eink/images/ in *.wbf files.
• Helper links to these files (named after waveform versions) are in /var/local/eink/.
• If file /var/local/eink/dont_update is present, the waveform won't be flashed. Ever.
• If file /var/local/eink/update_flash is present, the waveform will be flashed and then the file will be removed.

So all it takes to stop flashing the waveform is to create file /var/local/eink/dont_update . Easy peasy.
I can create a launchpad .ini file if someone's interested.

I created the file but the the waveform data is still lost on a restart.

[kelseyud]

So in theory, would there be a relatively easy software solution for this?

[mikeana]

Hi Nathiel,
My Kindle keyboard froze for no apparent reason. (later found a loose screw roling around inside)
After recharging, kindle finaly unfroze,but now had this "NO half-tone screen". After doing a "reset to factory defaults" it actualy got worse.(i think)
After reading your post, it seems like more or less the same problem (eink waveform) that you get as when changing screens.
I am not a soft ware expert, but do you think there is a solution for this?
Thanks

[Nephiel]

If the screen was working on that Kindle before, it should have a working waveform for it. I'd check if the connector got loose or the ribbon was damaged.

[mikeana]

I notice that when the screen saver is going on or off, the picture is good for a fraction of a seccond. The text also seems good on the home screen, but gets worse on a full page:
Wouldn´t that show more of a problem in the software/hardware and not so much with the eink waveform/screen?

[knc1]

Originally Posted by mikeana

I notice that when the screen saver is going on or off, the picture is good for a fraction of a seccond. The text also seems good on the home screen, but gets worse on a full page:
Wouldn´t that show more of a problem in the software/hardware and not so much with the eink waveform/screen?

Look for another loose screw shorting things out at random.

Also check the screen cables and their connectors as others have advised.

Your post that you found a loose screw in the K3 implies that you opened it, and also possibly handled the electronics.
Which means no one here can guess what else you should check.

[bshyrigh]

Originally Posted by tccsargent

This problem of the bad waveform almost exclusively lies with the 3G models of the Kindle Keyboard (and also with the 3g Kindle Touches). Here is a practical solution to your problem which, although not perfect, works most of the time: (1) Save the old, broken screen that you have removed from a 3G model of K3. (2) While the Kindle is still open, attach the new screen to it and navigate to "Reset to Factory Defaults" in the system submenu of the Kindle, and press Enter. (3) Press the arrow to navigate to "OK" of the Cancel-OK prompt which appears in the popup window for Reset to Factory Defaults, but do not press Enter yet. (4) Remove the new screen and re-connect the original broken screen; you will now be running blind, but you know that the Kindle is poised to reset with the pressing of the enter key. After the old screen is re-attached, go ahead and press Enter. (5) The Kindle will now reset to factory defaults, (hopefully) accessing the eprom chip on the ribbon cable of the old broken screen and loading the good waveform that resides there. Since you cannot watch the progress of this reset, give the Kindle at least FIVE minutes to complete the process before unplugging the old screen and re-plugging the new screen. Then slide the power bar and take a look: your 'wireframe' pictures should now be restored to solid rich grayscale!

I have repaired hundreds of Kindles and followed this procedure with around a 90% success rate. Unfortunately I have had some units (all 3G) which persistently reset to a bad, or missing, waveform, but the process has worked most of the time. Due to those failures, however, I have built up an inventory of around 50 broken 3G screens so that I can keep trying to find one to boot to which the subject Kindle will successfully read.

By the way, you should follow this procedure only after upgrading to 3.4 OS, since a later system upgrade (with a replacement screen installed) can again lead to a 'bad waveform' problem.


Good luck!

I'm halfway there.
I have 2 Kindles that I have recently replaced screens on due to broken/damaged. 1 is a 3G the other is WiFi only (both kindle3 running 3.4)
They both exhibited the washed out screen and google leads me here. The workaround described above went flawlessly with the 3G model but was ineffective with the WiFi model. So far I have tried restarting and resetting to factory default with all combinations of screen ribbons at my disposal. Is there a different workaround or other idea for the WiFi models?

[Ian.M]

Its pure luck if the waveform from the old screen matches the new one closely enough. Can you try swapping the screens (with the whole case front to minimise the risk of damage) over and see if the contrast problem follows the screen or the motherboard?