Repaper 2.7" difficulties

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IhautaI
 
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Repaper 2.7" difficulties

Post by IhautaI »

I bought the 2.7" repaper EPD + driver (https://www.adafruit.com/products/1346)
I have it on a BBB rev C with debian, up to date.

I've run through the setup and tried the examples. I set the screen size in /dev/default/epd-fuse. /dev/epd/panel spits out "EPD 2.7 264x176 COG 1"

The GPIO_test runs fine. epd_test does not appear to do anything and I get an error the first time it runs: "write_file only wrote: -1 of 3" four times, then "write_file only wrote: -1 of 4" once. Subsequent runs have no error until BBB is reset.
The screen has slowly gotten darker with the exception of the border.

The image appeared to be a bar code when I recieved it, the barcode is now a dark rectangle with a slightly lighter background, to the left are uniformly spaced dark and light rows. The top edge (just before the border) appears to have the bottom of a black rectangle.

I've tried some of the other examples after doing "make bb" and "make bb-install", nothing.

SPI appears to be working, I hooked up SCLK and MOSI to drive an LED to make sure.
I've tried to clear the screen with "echo C > /dev/epd/command". No errors, no change.

Thoughts? Ideas?

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adafruit_support_rick
 
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Re: Repaper 2.7" difficulties

Post by adafruit_support_rick »

The RePaper engineer will be available later this week to answer your question.

IhautaI
 
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Re: Repaper 2.7" difficulties

Post by IhautaI »

Any updates here?

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hsw
 
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Re: Repaper 2.7" difficulties

Post by hsw »

Hello IhautaI,
I am currently using a BBB Rev B4 running Debian:

Code: Select all

% cat /etc/debian_version 
7.6
% uname -srvmo 
Linux 3.8.13-bone40 #1 SMP Fri Jan 31 07:31:37 UTC 2014 armv7l GNU/Linux
This is running OK with the current code.

I have a second one (I will check the version tomorrow) that has had problems if the display is connected during a power cycle.
This one will recover if I disconnect the display PCB before power up, Wait until it is fully booted and I have connected to it via ssh.
Then I can connect the display PCB and it works correctly. I will examine this one to see if it has similar problems to yours.

Also, did you install the P9 GPIO cape manager files into /lib/firmware ?

Possibly there is some I/O difference on Rev C.
Once the epd-fuse is loaded it should have initialised all output lines to zero, are you able to check this?
(disconnect display PCB and use an LED with cathode to ground and a resistor (1k) to output pin)

IhautaI
 
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Re: Repaper 2.7" difficulties

Post by IhautaI »

I tried waiting until I'd SSH'd in, still not responding.
I did install the P9 GPIO cape manager in that directory.

The LED stays dark except with the expected VCC connections (orange # 18 and red # 1) when testing after the service is started and before connecting the EPD.

/etc/debian_version was 7.4 here, and it was Linux 3.8.13-bone47

I hooked up 3 LEDs w/ resistors. One was Yellow # 7 (SCLK), second was Blue # 15 (MOSI), and third was Brown # 9 (PWM). Running " echo C > /dev/epd/command" had this result: PWM and SCLK start together, PWM dropped out. MOSI cut on and off a large number of times, then stopped, SCLK stopped at roughly the same time, then came back on for a short time.

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hsw
 
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Re: Repaper 2.7" difficulties

Post by hsw »

Would you record the code numbers from the back of the display panel.
This is to determine if it is a COG 1 or 2;
the code should look something like: .VEM027BS01345Q4465
The "B" after the 027 indicates COG 2 (an "A" would indicate COG 1)

(This is the code is on the back of the display glass, not the one on the PCB)

IhautaI
 
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Re: Repaper 2.7" difficulties

Post by IhautaI »

It's a B, so COG 2. /dev/epd/panel says:
EPD 2.7 264x176 COG 1 however. Where should this value be changed?

IhautaI
 
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Re: Repaper 2.7" difficulties

Post by IhautaI »

Should I simply do what's shown here: http://adafruit.com/forums/viewtopic.php?f=19&t=56535
in your last post but with bb in place of rpi?

IhautaI
 
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Re: Repaper 2.7" difficulties

Post by IhautaI »

NM, that did it. It cleared!

Thanks for the help.

It may be worthwhile for Adafruit's tutorial to be updated showing the difference in startup/installation for COG1 and COG2.

One more happy person playing with Repaper's display here!

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hsw
 
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Re: Repaper 2.7" difficulties

Post by hsw »

The command sequence for the Beaglebone when the using a "B" display panel is:

Code: Select all

make bb-clean
make COG_VERSION=V2 bb
make COG_VERSION=V2 bb-install
reboot
After you did this, is it the display working now?

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adafruit_support_rick
 
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Re: Repaper 2.7" difficulties

Post by adafruit_support_rick »

IhautaI wrote:It may be worthwhile for Adafruit's tutorial to be updated showing the difference in startup/installation for COG1 and COG2.
Done!

@hsw - please review
https://learn.adafruit.com/repaper-eink ... -black/faq

IhautaI
 
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Re: Repaper 2.7" difficulties

Post by IhautaI »

Good stuff!

Thanks again!

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hsw
 
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Re: Repaper 2.7" difficulties

Post by hsw »

adafruit_support_rick wrote:
IhautaI wrote:It may be worthwhile for Adafruit's tutorial to be updated showing the difference in startup/installation for COG1 and COG2.
Done!

@hsw - please review
https://learn.adafruit.com/repaper-eink ... -black/faq
Looks good - thanks.

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