EInk Development board

[photonthunder]

Anyone had any luck getting the Eink display to work with the Raspberry pi. Just tried it with the latest debian image and I get no output to the display. I previously tried it with the Beaglebone black and got the same result. There is a code bug in epd_v1.c so you have to use version 2. Any input is appreciated.

[adafruit_support_mike]

Have you set it up as in the tutorial?

https://learn.adafruit.com/repaper-eink ... k/overview

[photonthunder]

Yes, I followed the tutorial and I got the same response as on the Beaglebone Black. I am thinking there is some little step that is was left out of the tutorial, since if you followed it as described you wouldn't even get it to compile because of the code error (which has been updated in the git repo). Anyone actually get this to work, going to try an Arduino board next to see what it gives me.

[adafruit_support_mike]

Let's check the basics: please post a photo of your hardware with enough detail to show the connections and the soldering. The forum limits file sizes to 1M, but 800x600 images usually work well.

[photonthunder]

Here is a photo showing the connection for the Beaglebone and Raspberry Pi.

photo.JPG (538.68 KiB) Viewed 618 times

[photonthunder]

Got this working on the arduino Mega and beaglebone black (have not retried on the raspberry pi). I had a pin connection error on the Beaglebone, and there was a slight code error for version 1 and version 2 will not work with the pervasive display extension board. Hope this helps someone.

[cyberchucktx]

I'm trying to use the 2.7 EPD with a BaegleBoneBlack. Although everything appears to work (compile,d etc) I get no display. SIUs there any debugging code I can add to the Python to see *something* ?

My next step will be to hook up the 7" and 10" displays, but if I can't get the
2.7" working what's the point?

[adafruit_support_mike]

The BBB has changed since may.. there's a new hardware version and a new OS.

What OS and version are you running?

[cyberchucktx]

I discovered that the default boot on my BBB (BeagleBoneBlack) is DEBIAN, not Angstrom; all the instructions I have say that the EPD requires Angstrom. I'm in the process of loading up Angstrom to the eMMC, will report back soon (I, too, have a 2.7 EPD as well as a 7" and 10").

[raminf]

I'm having trouble running the 2.7" eInk on a BeagleBone Black as well. This is under Angstrom v2012.12 with hardware circa 2013 (pretty sure it's an A6 version hardware).

There are a couple of issues:

1) The picture in the tutorial shows the cable and connector not being the same size (https://learn.adafruit.com/assets/12841). The one I received has the the same number and the connector on the board and looks more like the one in the BBB-specific section (https://learn.adafruit.com/assets/12496).

However, the wire colors in the BBB tutorial are different than the ones listed in the text. So I went with the pin numbering listed in the tutorial but my wiring doesn't come out looking like the picture for BBB (https://learn.adafruit.com/assets/12496).

Looks like the pin number and color values in the BBB tutorial need to be updated.

2) After having installed all the software and drivers (along with the as instructed I ran the DrawDemo.py example and get an error:

IOError: [Errno 107] Transport endpoint is not connected: '/dev/epd/version'

At this point, I'm guessing this is probably because the wires are in the wrong order...

Any suggestions?

[cyberchucktx]

I am pretty sure that you don't have the EPD server running.

I DID get the EPD working just fine under RaspberryPI; I'm abandoning the BBB (BeagleBoneBlack) from now on. Once I get things running I plan to:

1) Buy a BananaPI (it is almost 3 times faster CPU-wise)
2) Publish the specs (wiring diagrams) for the PI Cobbler board for the EPD ( https://www.adafruit.com/products/914 ).

Please post back to this if you have any questions.

[raminf]

Thanks @CyberchuckTX. I checked and the EPD server was, in fact, down. I had to manually restart it and then I could get the panel version:

# cat /dev/epd/panel
EPD 2.7 264x176 COG 2

But then trying to clear the panel like this broke things:

# echo C > /dev/epd/command
-bash: echo: write error: Software caused connection abort
# cat /dev/epd/version
cat: /dev/epd/version: Transport endpoint is not connected

So trying to write to the device crashed the server (which is probably why I was getting that error in the first place). I'm still not sure what wiring scheme to use for the BBB, the color values listed in the tutorial are not the same as the ones in the cable connector I have. Following the raw pin numbers didn't work either. I then tried to make the pinouts look like the ones in the BBB tutorial pictures but there are multiples of the same color. I'm not confident I got it right.

I'm hoping someone from Adafruit will update the e-Ink BBB tutorial with pinouts that match the current shipping cable (the version shown in the BBB tutorial photos).

[raminf]

OK, problem solved. Here's what worked:

1. First of all, the wiring description and coloring in the BBB tutorial is correct. What I missed was the pin numbering scheme on the connector cable. Pin 1, as noted is the docs is the one with the white dot in front of it (might want to reapply the dot with a silver Sharpie pen or a dab of nail polish. That white dot rubs off pretty easily.)

So apparently Pin 2, is NOT the pin vertically below Pin 1. It's the one across from it. The one vertically below it is Pin 3. So if you hold the cable connector end that goes to the eInk board vertically so Pin 1 is the one with the white dot and if you go vertically down the pin numbers are 1, 3, 5, 7, 9,... and the vertical row on the other side is 2, 4, 6, 8, ...

Like so:

p1 p2
p3 p4
p5 p6
...

(In my defense, I'd just come over from wiring up JTAG cables with 2 rows of 10 pins where the pin order is:

p1 p11
p2 p12
p3 p3
...

Once you get the numbers worked out the cable colors match and now you can wire up the BBB. If wondering what the BBB pinouts are this is a handy diagram: http://insigntech.files.BANNED.com/2 ... inouts.jpg

Basically, if you hold the BBB so the Ethernet and 5V barrel connector are facing up and toward you, the leftmost row of pins are:

P9-01 P9-02
P9-03 P9-04
P9-05 P9-05
...

Make sure you double-check the wiring because it's easy to get the pinouts wrong. This way the wire colors listed in the BBB tutorial do match and you should be good to go.

2. Once wiring is set up the software still didn't want to work. I found this blog post useful:

http://monkeyiq.blogspot.com/2013/11/re ... -from.html

One of the baby steps you can take is to not go through the FUSE driver but to run the basic C tests first. Download and build the gratis code first. One road bump in downloading the gratis and beaglebone files from git is that you may get SSL errors.

Go here: http://derekmolloy.ie/fixing-git-and-cu ... bone-blac/ and follow "Solution 2" to install ca-certificates and set up git properly.

Now go get the git repos. It's possible you'll have to build the make files with COG_VERSION=V2 on the make command lines, so watch out for that. Then go into gratis/PlatformWithOS/driver-common and try manually running ./epd_test. Give it your eInk board size. If you get the image tests working, you're good to go.

In my case, not so good. I got a 'missing /dev/spidev1.0' error. To get that working, you'll want to head over to http://elinux.org/BeagleBone_Black_Enable_SPIDEV and scroll down past the SPI1 sections and look for the section under SPI0. Follow the instructions to build and install. If that doesn't work, you can try http://www.linux.com/learn/tutorials/74 ... bone-black and see maybe that will let you get access to /dev/spidev1.0.

Once the system is rebooted and it's all set, now go back into the gratis/PlatformWithOS/driver-common folder and run ./epd_test {screen-size}.

If that doesn't work, then try patching the code as described in the bottom of the monkeyiq post (http://monkeyiq.blogspot.com/2013/11/re ... -from.html), then rebuild and retry.

After all of this, I finally got the test images on my screen.

However, to get the python demo files to work you have to install the EPD FUSE service and if that doesn't want to stay up, the Python demos won't work (this is where I came here and started this thread). However, the FUSE service will not stay up until you go through the above configuration to make sure you can access the /dev/spidev1.0 device. Once that was configured properly, the epd_fuse service stayed up after a reboot (to verify, run 'ps -ef | grep eps' and you should see something like:

root 317 1 0 22:53 ? 00:00:01 /usr/sbin/epd_fuse --panel=2.7 -o allow_other -o default_permissions /dev/epd

If that's up and running, now you can run the Python demos and everything should work.

OK, sorry for the long note, but let's hope this helps someone else trying to get this working with the BBB. It took way longer than I expected but at least it's working now and looks pretty solid.

BTW, if anyone's looking for more information on these display boards from the manufacturer: http://www.pervasivedisplays.com/products/panels

[adafruit_support_mike]

That's a great walkthough.. than you for posting it.