Waveshare 7.5” ePaper display issue with GxEPD2 library

Other Hardware Displays
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I have a Waveshare 7.5” e-paper display V2 (800 x 480) and am using the GxEPD2 library (version 1.4.9) for evaluation purposes. I am experiencing a problem when using the example program “GxEPD2_HelloWorld". The program works (sort of) but after the display prints out the “Hello World” text it fades out almost completely and is very faint and no longer readable.

I have tried this using two different platforms: An Arduino Uno and an ESP8266 DevKitC_V1 with the exact same symptoms. Is this an issue with the display or something more basic?

PS. I also tried this exact setup (same sketch and same platforms) with a Waveshare 2.13" e-paper display and it works w/o a hitch.

Thanks in advance, George

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@jungle417, Hi,

Before trying to help you, I need to know exactly which e-paper panel you have, and which panel or constructor you selected in GxEPD2. And the connection module used.

Is it this one: 800×480, 7.5inch E-Ink raw display, SPI interface, without PCB | WF0583CZ09 (waveshare.com)? Check the inking on the flex cable.

Jean-Marc

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I’m using this panel: https://www.waveshare.com/product/displays/e-paper/epaper-1/7.5inch-e-paper-hat.htm (V2). The back of the display has a sticker reading 075BN-T7.

For the ESP8266 DevKitC_V1 I’m using following constructor (note the modified pin assignments):

GxEPD2_BW < GxEPD2_750_T7, GxEPD2_750_T7::HEIGHT / 2 > display(GxEPD2_750_T7(/CS=D8/ 5, /DC=D3/ 2, /RST=D4/ 12, /BUSY=D2/ 4)); // GDEW075T7 800x480, GD7965

As noted in the README.md section of your library, in order to get the sketch to run I

had to modify init(115200) to init(115200, true, 2, false) and tie RST to 3.3v via a 1k resistor.

UPDATE: I just fixed it! Th switch on the HAT was in the "A" position of the Display Config switch. I moved it to the "B" position and all is well.

Thanks for your response anyway though

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