Unable to get EPD working with flexible 2.9 and e-ink friend Moderators: adafruit_support_bill, adafruit

[jasonthenderson]

I have been trying without luck to get the EPD friend and 2.9 flexible working with the Huzzah32. I also got a 2.1 feather monochome and I was able to get that working with the same Huzzah32 just fine. When I connect the friend using the same pins that I see used for the feather I am not able to get any kind of a response from the screen. i.e. it still shows the "Ok" that came from the factory. I've tried hooking up reset, enable pins, setting srcs to -1, nothing helps. There is literally no response on the display. Using the exact same code that I run with the feather except that I changed the resolution to match the 2.9.

Any ideas? Did I get a bum e-ink friend?

[adafruit_support_carter]

Can you post a photo of your setup showing how you have everything connected together. Which library are you using and what example are you running?

[jasonthenderson]

Thank you for the response! I am exactly using the code from here: https://learn.adafruit.com/epaper-displ ... uino-setup with the libraries specified. It works fine if I swap out the friend for the featherwing and leave everything else the same, but the friend does nothing.

Attached picture of my setup.

[adafruit_support_carter]

It may be the differences in actual EPD. The FeatherWing and that guide you linked use the 2.13" EPD. The EPDs are all a little different. So that specific code may not work with the 2.9" EPD.

Try running the example from the EPD library:
https://github.com/adafruit/Adafruit_EP ... PDTest.ino
and comment/uncomment as needed for the 2.9" EPD. Also check the #defines for EPD_CS, EPD_DC , etc. to make sure they match the pins you are using.

[jasonthenderson]

That did the trick, thank you for the help. One suggestion I do have would be to include a mapping somewhere in the core documentation of each of the EPDs that Adafruit sells and the specific line that should be used, or perhaps in the description in the store call it out clearly, or link to it. I spent many hours trying different combinations because I didn't stumble across that one example that declared the line to use for 2.9. Many of the examples, including the quote example, didn't include a line for 2.9 so I tried using others that I thought were similar enough. Thank you again!

[adafruit_support_carter]

Cool. Glad that got it working.

Were the other examples from guides that were written for specific EPDs? It looks like all the examples in the library:
https://github.com/adafruit/Adafruit_EP ... r/examples
have those boiler plate lines at the top. That one guide you linked was specific to the FeatherWing. Where else were you looking at examples?

[jasonthenderson]

You got me :) I think all of the code I looked at was the Featherwing example, as well as the documentation here: https://learn.adafruit.com/adafruit-ein ... duino-code

I thought, incorrectly that this would define all the different possible supported EPDs that adafruit sells.

Obviously I was wrong. Now, I do know where to look.