Display 4 shades of grey on E-paper display

Other Hardware Displays
1

Hi, I am relatively new to programming Arduino.
A few weeks ago I bought a Waveshare 3.7inch E-paper Display. I was able to display black and withe pictures but I didn´t get the 4 greyscale to work. I already downloaded the Image to LCD application and copied it in the IMAGE_DATA array, but it didn´t work. Seems like the 4-greyscale application isn´t implemented in the programm or I wasn´t able to get access to it. Is there any specific code I have to implement in my programm to get it to work?
I used the example code shown on:

2

DroneBotWorkshop wrote about e-paper. One line that I saw looked like it had the ability to be any of 256 shades (this is for background, but same parameter for image)

    # clear display, 0 is black, 255 is white
    epd_disp.Clear(255)

This is the reference:

3

Thanks for your help. I don`t think this line has the ability to declare any of 256 shades because the display only has the ability to display 4 shades of black/withe. Tried out the code of the 2.7inch display on my 3.7inch one but it did´t work. The Problem is, I wasn´t able to find a libary for my 3.7inch display that supports displaying 4 shades of grey.

4

In the Arduino Code example from waveshare there is this part of the code, that seems to have something to do with displaying 4 shades of grey:
static const UBYTE lut_4Gray_GC[] =
{
0x2A,0x06,0x15,0x00,0x00,0x00,0x00,0x00,0x00,0x00,//1
0x28,0x06,0x14,0x00,0x00,0x00,0x00,0x00,0x00,0x00,//2
0x20,0x06,0x10,0x00,0x00,0x00,0x00,0x00,0x00,0x00,//3
0x14,0x06,0x28,0x00,0x00,0x00,0x00,0x00,0x00,0x00,//4
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,//5
0x00,0x02,0x02,0x0A,0x00,0x00,0x00,0x08,0x08,0x02,//6
0x00,0x02,0x02,0x0A,0x00,0x00,0x00,0x00,0x00,0x00,//7
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,//8
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,//9
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,//10
0x22,0x22,0x22,0x22,0x22
};

But still i don´t know how to get access to it.

5

What is "it?"

6

Access to displaying 4 shades of grey.

7

It looks like only the STM32 demo from Waveshare shows use of 4 grey levels:
https://github.com/waveshareteam/e-Paper/blob/master/STM32/STM32-F103ZET6/User/Examples/EPD_3in7_test.c

BITMAPS GRAYSCALE WITH Adafruit_GFX AND GxEPD2_EPD
8

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