2.9 ePaper Module, EPS32 and GxEPD2

Other Hardware Displays
1

Hi there,

i need some help with the GxEPD2 Library and a 2.9'' ePaper Module.

the pins i need to use (and are wired) are these:

#define PIN_DISPLAY_SCL     22
#define PIN_DISPLAY_SDA      21
#define PIN_DISPLAY_CS        14
#define PIN_DISPLAY_DC        12
#define PIN_DISPLAY_RESET     13
#define PIN_DISPLAY_BUSY      25

this is the code i am using:


#include <GxEPD2_BW.h>

#define ENABLE_GxEPD2_GFX 0
GxEPD2_290_BS displayDriver(/*CS=*/PIN_DISPLAY_CS, /*DC=*/PIN_DISPLAY_DC, /*RST=*/PIN_DISPLAY_RESET, /*BUSY=*/PIN_DISPLAY_BUSY);
GxEPD2_BW<GxEPD2_290_BS, GxEPD2_290_BS::HEIGHT> display(displayDriver);

void initializeDisplay()
{
  display.init(115200, true, 2, false); // USE THIS for Waveshare boards with "clever" reset circuit, 2ms reset pulse
  helloWorld();
  display.hibernate();

}

void helloWorld()
{
  display.setRotation(1);
  display.setFont(&FreeMonoBold9pt7b);
  display.setTextColor(GxEPD_BLACK);
  int16_t tbx, tby; uint16_t tbw, tbh;
  display.getTextBounds("HelloWorld", 0, 0, &tbx, &tby, &tbw, &tbh);
  // center the bounding box by transposition of the origin:
  uint16_t x = ((display.width() - tbw) / 2) - tbx;
  uint16_t y = ((display.height() - tbh) / 2) - tby;
  display.setFullWindow();
  display.firstPage();
  do
  {
    display.fillScreen(GxEPD_WHITE);
    display.setCursor(x, y);
    display.print("HelloWorld");
  }
  while (display.nextPage());
}

the issue is, that nothing is happening. is there anything wrong with the pins? with the code?

any help would be just great!! Thanks a lot!

PS.: the board is a DevKITV1, this is the library: GitHub - ZinggJM/GxEPD2: Arduino Display Library for SPI E-Paper Displays

2

You use uncommon pins for SPI. Are these the HW SPI pins for the board you use?

Please provide this information in addition:

  • link to the processor
  • board selected to compile for
  • link to the display module
3

Hi there, i have managed to reqire the hardware to use the standard spi pins.
Now the display works... ...still lots of stuff to figure out, but i got a first glimps of a working display :wink:

cheers!