Sharing same SPI with LoRa/LMIC and Epaper

I am trying to configure my HeltecV2. Idea is to share the same SPI with LMIIC and Epaper (Waveshare 2,9" using GxEPD). Is it even possible?

My Pin mapping is below

//// Pin mapping
const lmic_pinmap lmic_pins = {
.nss = 18,
.rst = 14,
.dio = {26, 34, 35},

GxIO_Class io(SPI, /CS=/ 17, /DC=/ 23, /RST=/ 16);
GxEPD_Class display(io, /RST=/ 16, /BUSY=/ 2);

Epaper data in is connected to same MOSI pin 27 and CLK pin5

LoRa part works nicely but I havent got this Epaper working on this board. (It works nicely with Arduino UNO) Can someone help please!


If the ePaper display does not work on your HeltecV2 then you will need to solve that problem first, before you think of sharing the SPI with LoRa\LMIC.

Have you checked if your ePaper library is ESP32 compatible ?

Yes, I believe this is the main issue. Still unsuccefull.

GxEPD should be ESP32 compatible.

The Epaper displays do work on a shared SPI bus, but your question is not related to that, the question is really, why does my display not work an my ESP32 ?

This may not be the best place to solve a problems with your ESP32 hardware, the ESP32 itself (which is not an Arduino) is supported by Expressif or perhaps the Arduino\Displays forum.

GxEPD should be ESP32 compatible.

Should be, but is it ?

Extensive thread on the GxEPD library over in the Arduino\Display forums;

Almost 1,500 messages, might be some useful information in there.