Hi,
I can operate my Waveshare 7.5" 3-color 800x480 e-paper.
But I use my library GxEPD2 and usually DESPI-C02 for connection.
I have no experience with the Waveshare demo code epd7in5b_V2-demo.ino.
Your e-paper and connection module seem to be: 800×480, 7.5inch E-Ink display HAT for Raspberry Pi, three-color
The wiki page is: https://www.waveshare.com/wiki/7.5inch_e-Paper_HAT_(B)
Waveshare has a link on that page to this topic, that's why you ask here, most likely.
You see, it takes already some effort to collect this information, and it gets much easer for any reader or helper if clickable links are provided.
For a start you could read General Guidance and How to use the Forum
I can take a look at their code in the meantime, to see where they select the pins, and if they correspond to your wiring.
Jean-Marc
In https://github.com/waveshare/e-Paper/blob/master/Arduino/epd7in5bc_V2/epdif.h
// Pin definition
#define RST_PIN 8
#define DC_PIN 9
#define CS_PIN 10
#define BUSY_PIN 7
Did you adapt these values to your wiring?
BTW: the e-paper hat may supply insufficient voltage to the e-paper, when connected to 3.3V, because of the LDO. This may cause malfunction, especially for the big e-paper panels.
https://github.com/waveshare/e-Paper/blob/master/Arduino/epd7in5bc_V2/epdif.cpp
At least they now use HW SPI:
#include "epdif.h"
#include <SPI.h>
But claim exclusive use of SPI:
int EpdIf::IfInit(void) {
pinMode(CS_PIN, OUTPUT);
pinMode(RST_PIN, OUTPUT);
pinMode(DC_PIN, OUTPUT);
pinMode(BUSY_PIN, INPUT);
SPI.begin();
SPI.beginTransaction(SPISettings(2000000, MSBFIRST, SPI_MODE0));
return 0;
}
