Problem with GxEPD2 (E-Ink display) and ESP8266

Hello guys,

I’ve got some problem(s). I’m a web developer and I’ve got a project who need a Eink screen with API update, why I choosed de ESP8266 with built in Wifi module (ESP8266MOD).

My simple code is :

#define ENABLE_GxEPD2_GFX 0

#include <GxEPD2.h>
#include <GxEPD2_3C.h>
#include <GxEPD2_7C.h>
#include <GxEPD2_BW.h>
#include <GxEPD2_EPD.h>
#include <GxEPD2_GFX.h>

GxEPD2_3C<GxEPD2_420c, GxEPD2_420c::HEIGHT / 2> display(GxEPD2_420c(/*CS=15*/ SS, /*DC=4*/ 4, /*RST=2*/ 2, /*BUSY=5*/ 5));

#include "GxEPD2_boards_added.h"

void setup() {
  display.init(115200);
  display.fillScreen(GxEPD_BLACK);
}

void loop() {}

Pins are correctly connected (CS on GPIO15, DC on GPIO4, RST on GPIO2 and RST on GPIO5) and the project is successfully compiled and uploaded on the ESP8266 (I tried with some builtin led flash).
I put a 4.7K resistor between CS PIN and a GND free pin because without that, Arduino IDE can’t connect and upload project (but with resistor connection is OK, I saw this issue in a forum but I don’t know if is it the correct issue for the connecting Arduino IDE problem, but is seems to work).

I’ve got any error but screen don’t fill screen in black. Do I have some code error ? Or the problem is the resistor ?

ESP8266 is a 8266MOD from DOIT.AM. Screen in E-Ink display 4.2inch 3 colors from Waveshare.

I know that my electronic knowledge are very poor but if someone can help me, i would be great :grinning:

PS : Is there a way to test if display is rightly connected ?

Which board do you choose during compile?

Post a complete wiring diagram! Using the connections you mentioned the screen won't work as there is no SPI bus connection and no power/ground connectivity.

Post links to the used libraries!

Or the problem is the resistor ?

Haven't you tried to run the sketch without it?

PS : Is there a way to test if display is rightly connected ?

If it works, it's correctly connected.