Template: 6inch HD e-Paper user manual

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Introduction

  • 6inch e-Paper HAT uses IT8951 as a controller, it can be controlled by USB/SPI/I80/I2C interface with the resolution of 1448 × 1072, 6inch EPD (Electronic Paper Display) display.
  • It has the advantages of low power consumption, wide viewing angle, and clear display under direct sunlight, and is often used in display applications such as shelf labels and industrial instruments.

Features

  • No backlight, keeps displaying last content for a long time even when power down.
  • Low power consumption, basically power is only required for refreshing.
  • Its design is based on the Raspberry Pi 40PIN GPIO interface, suitable for the Raspberry Pi series.
  • Lead out USB/SPI/I80/I2C control interface, which can be connected to main control boards such as Raspberry/Nucleo.
  • Provide information manuals (example programs such as Raspberry/STM32).

Specification

  • Operating voltage: 5V
  • Interface: USB/SPI/I80/I2C
  • Outline dimension: 138.4mm X 101.8mm X 1.01mm
  • Display size: 122.356mm X 90.584mm
  • Dot pitch: 0.0845mm X 0.0845mm
  • Resolution: 1448 X 1072
  • Display color: black, white
  • Grayscale: 2-16 (1-4 bit)
  • Full refresh time: <1s
  • Refresh power: 0.6W (typ.)
  • Standby power: 0.3W (typ.)
  • Viewing angle: >170°

Working with Windows PC (USB)

Working Principle

The electronic paper in this product uses the "microcapsule electrophoresis display" technology. The principle is that the charged nanoparticles suspended in the liquid are migrated by the electric field. The e-paper screen displays patterns by reflecting ambient light and does not require a backlight. Under ambient light, the e-paper display screen is clearly visible, with a viewing angle of almost 180°. Therefore, the e-paper display is perfect for reading.

  • Connect the e-Paper to the driver board.
6inch-HD-e-Paper-HAT-1.jpg
  • Connect the driver board to the PC by USB cable.
  • Download and run the E-LINK-TCON-DEMO software, you can download the software from #Resources.
  • Click connect.
6inch-HD-e-Paper-HAT-Manual-02.jpg
  • Check the "AutoSet" option, click "Open File" to select the picture, and click "OK" to confirm.
6inch-HD-e-Paper-HAT-Manual-03.jpg
  • Click Display to update the e-Paper.
6inch-HD-e-Paper-HAT-Manual-04.jpg
  • Note: If you want to use the USB interface to develop e-Paper on Windows, which need to contact the Waveshare team and sign NDA before you can get the E-LINK-TCON-DEMO source code.

Working with Raspberry Pi (SPI)

  • Hardware connection
You should add the IT8951 Driver HAT on Raspberry Pi, communicating via SPI interface.
6inch-e-Paper-HAT-Manual-06.jpg
You can also connecting by wires
Connect to Raspberry Pi via SPI
IT8951 Driver HAT Raspberry Pi (BCM) Description'
5V 5V 5V power input
GND GND Ground
MISO P9 MISO Pin of SPI
MOSI P10 MOSI Pin of SPI
SCK P11 SCK Pin of SPI
CS P8 Chip selection of SPI (Low active)
RST P17 Reset pin (Low active)
HRDY P24 Busy stats pin (Low when busy)
  • Set the DIP switch to SPI mode.
6inch-HD-e-Paper-HAT-Manual-05.png
  • Open terminal of Raspberry Pi, and install bcm2835 libraries.
wget http://www.airspayce.com/mikem/bcm2835/bcm2835-1.60.tar.gz
tar zxvf bcm2835-1.60.tar.gz
cd bcm2835-1.60
./configure
make
sudo make check
sudo make install
  • Enable SPI interface
sudo raspi-config

Choose Interfacing Options ->SPI->Yes.

  • Download demo codes and compile them.
    • Method 1: Download from our website. (Recommended)
sudo apt-get install p7zip-full
sudo wget  https://www.waveshare.com/w/upload/8/80/IT8951_20200319_Release.7z
7z x IT8951_20200319_Release.7z -O./IT8951
cd IT8951/
sudo make clean
sudo make -j4
    • Method 2: Download from Github:
git clone https://github.com/waveshare/IT8951-ePaper.git
cd IT8951-ePaper/Raspberry
sudo make clean
sudo make -j4
  • Check the VCOM value on the FPC.
6inch-HD-e-Paper-HAT-Manual-06.png

Add the VCOM value as a parameter and test the e-Paper, and this model is mode 0.

sudo ./epd -1.78 0
  • Demo execution phenomenon:

1) First, the r-paper will refresh the 16 gray bars partially in sequence.

2) Then demonstrate the demo of drawing lines, circles, rectangles, characters, and numbers.

3) Then respectively demonstrate the demo of displaying BMP pictures in 1bp, 2bp, and 4bp modes.

4) Next, demonstrate the effect of fast refresh in A2 mode.

5) Then display a gif animation.

6) Then demonstrate a Demo that counts the frame rate.

7) Finally, the e-paper is whitened in Init mode for long-term storage.

Working with STM32 (SPI or I80)

  • Choose interface
    • We recommend you to use SPI interface as the pins of SPI interface are less and easy to use
    • If the speed of SPI interface is slow for you, you can choose I80 interface which is fast, however, too much pins
  • Choose MCU
Because IT8951 requires a big RAM for data, some of the STM32 boards don't have enought RAM without external SDRAM. Here we use Waveshare Open429I which has IS42S16499J (64-MBIT) SDAM on board.

SPI interface

IT8951 Driver HAT STM32 Description'
5V 5V 5V power input
GND GND Ground
MISO PE13 MISO Pin of SPI
MOSI PE14 MOSI Pin of SPI
SCK PE12 SCK Pin of SPI
CS PE11 Chip selection of SPI (Low active)
RST PC5 Reset pin (Low active)
HRDY PA7 Busy stats pin (Low when busy)
  • Set the switch to SPI mode
6inch-HD-e-Paper-HAT-Manual-05.png
Unzip the demo codes and open the project by Keil. The path o the code is Open429I-C-6-IT8951-Demo\Project\6-IT8951\MDK-ARM\Project.uvproj.
Compile project, modify IT8951.h file, enable SPI interface, then compile again and program it to STM32 board.
9.7inch-e-Paper-HAT-Manual-15.jpg
  • You can check the debug information via UART interface
6inch-HD-e-Paper-HAT-Manual-07.jpg

I80 interface

  • Connect e-Paper
IT8951 Driver HAT STM32 Description'
DBUS0~DBUS15 PB0~PB15 Data pins
HWE PC1 Write enable (Low active)
D/C PC7 Data/Command(Low for command)
CSEL PC6 Chip select enable (Low active)
HRD PC3 Read enable (Low active)
RST PC0 Reset pin (Low active)
PA7 Busy stats pin (Low when busy)
GND GND Ground
VCC 5V 5V power input
  • Set the switch to I80
9.7inch-e-Paper-HAT-Manual-17.jpg
Unzip the demo codes and open the project by Keil. The path o the code is Open429I-C-6-IT8951-Demo\Project\6-IT8951\MDK-ARM\Project.uvproj.
Compile the project, and modify the IT8951.h file. Make sure IT8951_Interface_I80 is defined, click Recompile, and download. After a few seconds, you can see that the e-paper starts to display pictures in a loop.
9.7inch-e-Paper-HAT-Manual-15.jpg
  • You can check the debug information via the UART interface:
6inch-HD-e-Paper-HAT-Manual-07.jpg

Make image arrays

For easily porting and using, we didn't use file system in the STM32 code. The image showed is saved as arrays. Here show you how to make the image arrays.

  • You should firstly make an BMP file, the resolution of the e-Paper is 1448*1072, you had better resize your picture accoridng to the resolution (less or equal to)
6inch-e-Paper-HAT-Manual-09.jpg6inch-e-Paper-HAT-Manual-10.jpg
  • Click File->Save As...-> Choose type "C" butmap file(*.c) -> input the file name and save
  • Select 8 bit per pixel and OK to get the .c file
9.7inch-e-Paper-HAT-Manual-21.jpg
  • Add the .c file to project and delect unuse information
/*********************************************************************
*                SEGGER Microcontroller GmbH & Co. KG                *
*        Solutions for real time microcontroller applications        *
*                           www.segger.com                           *
**********************************************************************
*                                                                    *
* C-file generated by                                                *
*                                                                    *
*        Bitmap Converter for emWin V5.22.                           *
*        Compiled Jul  4 2013, 12:18:24                              *
*        (c) 1998 - 2013 Segger Microcontroller GmbH && Co. KG       *
*                                                                    *
**********************************************************************
*                                                                    *
* Source file: zoo_800_600                                           *
* Dimensions:  800 * 600                                             *
* NumColors:   256                                                   *
*                                                                    *
**********************************************************************
*/
 
#include <stdlib.h>
 
#include "GUI.h"
 
#ifndef GUI_CONST_STORAGE
  #define GUI_CONST_STORAGE const
#endif
 
extern GUI_CONST_STORAGE GUI_BITMAP bmzoo_800_600;
 
/*********************************************************************
*
*       Palette
*
*  Description
*    The following are the entries of the palette table.
*    The entries are stored as a 32-bit values of which 24 bits are
*    actually used according to the following bit mask: 0xBBGGRR
*
*    The lower   8 bits represent the Red   component.
*    The middle  8 bits represent the Green component.
*    The highest 8 bits represent the Blue  component.
*/
static GUI_CONST_STORAGE GUI_COLOR _Colorszoo_800_600[] = {
  0x000000, 0x010101, 0x020202, 0x030303,
  0x040404, 0x050505, 0x060606, 0x070707,
  0x080808, 0x090909, 0x0A0A0A, 0x0B0B0B,
  0x0C0C0C, 0x0D0D0D, 0x0E0E0E, 0x0F0F0F,
  0x101010, 0x111111, 0x121212, 0x131313,
  0x141414, 0x151515, 0x161616, 0x171717,
  0x181818, 0x191919, 0x1A1A1A, 0x1B1B1B,
  0x1C1C1C, 0x1D1D1D, 0x1E1E1E, 0x1F1F1F,
  0x202020, 0x212121, 0x222222, 0x232323,
  0x242424, 0x252525, 0x262626, 0x272727,
  0x282828, 0x292929, 0x2A2A2A, 0x2B2B2B,
  0x2C2C2C, 0x2D2D2D, 0x2E2E2E, 0x2F2F2F,
  0x303030, 0x313131, 0x323232, 0x333333,
  0x343434, 0x353535, 0x363636, 0x373737,
  0x383838, 0x393939, 0x3A3A3A, 0x3B3B3B,
  0x3C3C3C, 0x3D3D3D, 0x3E3E3E, 0x3F3F3F,
  0x404040, 0x414141, 0x424242, 0x434343,
  0x444444, 0x454545, 0x464646, 0x474747,
  0x484848, 0x494949, 0x4A4A4A, 0x4B4B4B,
  0x4C4C4C, 0x4D4D4D, 0x4E4E4E, 0x4F4F4F,
  0x505050, 0x515151, 0x525252, 0x535353,
  0x545454, 0x555555, 0x565656, 0x575757,
  0x585858, 0x595959, 0x5A5A5A, 0x5B5B5B,
  0x5C5C5C, 0x5D5D5D, 0x5E5E5E, 0x5F5F5F,
  0x606060, 0x616161, 0x626262, 0x636363,
  0x646464, 0x656565, 0x666666, 0x676767,
  0x686868, 0x696969, 0x6A6A6A, 0x6B6B6B,
  0x6C6C6C, 0x6D6D6D, 0x6E6E6E, 0x6F6F6F,
  0x707070, 0x717171, 0x727272, 0x737373,
  0x747474, 0x757575, 0x767676, 0x777777,
  0x787878, 0x797979, 0x7A7A7A, 0x7B7B7B,
  0x7C7C7C, 0x7D7D7D, 0x7E7E7E, 0x7F7F7F,
  0x808080, 0x818181, 0x828282, 0x838383,
  0x848484, 0x858585, 0x868686, 0x878787,
  0x888888, 0x898989, 0x8A8A8A, 0x8B8B8B,
  0x8C8C8C, 0x8D8D8D, 0x8E8E8E, 0x8F8F8F,
  0x909090, 0x919191, 0x929292, 0x939393,
  0x949494, 0x959595, 0x969696, 0x979797,
  0x989898, 0x999999, 0x9A9A9A, 0x9B9B9B,
  0x9C9C9C, 0x9D9D9D, 0x9E9E9E, 0x9F9F9F,
  0xA0A0A0, 0xA1A1A1, 0xA2A2A2, 0xA3A3A3,
  0xA4A4A4, 0xA5A5A5, 0xA6A6A6, 0xA7A7A7,
  0xA8A8A8, 0xA9A9A9, 0xAAAAAA, 0xABABAB,
  0xACACAC, 0xADADAD, 0xAEAEAE, 0xAFAFAF,
  0xB0B0B0, 0xB1B1B1, 0xB2B2B2, 0xB3B3B3,
  0xB4B4B4, 0xB5B5B5, 0xB6B6B6, 0xB7B7B7,
  0xB8B8B8, 0xB9B9B9, 0xBABABA, 0xBBBBBB,
  0xBCBCBC, 0xBDBDBD, 0xBEBEBE, 0xBFBFBF,
  0xC0C0C0, 0xC1C1C1, 0xC2C2C2, 0xC3C3C3,
  0xC4C4C4, 0xC5C5C5, 0xC6C6C6, 0xC7C7C7,
  0xC8C8C8, 0xC9C9C9, 0xCACACA, 0xCBCBCB,
  0xCCCCCC, 0xCDCDCD, 0xCECECE, 0xCFCFCF,
  0xD0D0D0, 0xD1D1D1, 0xD2D2D2, 0xD3D3D3,
  0xD4D4D4, 0xD5D5D5, 0xD6D6D6, 0xD7D7D7,
  0xD8D8D8, 0xD9D9D9, 0xDADADA, 0xDBDBDB,
  0xDCDCDC, 0xDDDDDD, 0xDEDEDE, 0xDFDFDF,
  0xE0E0E0, 0xE1E1E1, 0xE2E2E2, 0xE3E3E3,
  0xE4E4E4, 0xE5E5E5, 0xE6E6E6, 0xE7E7E7,
  0xE8E8E8, 0xE9E9E9, 0xEAEAEA, 0xEBEBEB,
  0xECECEC, 0xEDEDED, 0xEEEEEE, 0xEFEFEF,
  0xF0F0F0, 0xF1F1F1, 0xF2F2F2, 0xF3F3F3,
  0xF4F4F4, 0xF5F5F5, 0xF6F6F6, 0xF7F7F7,
  0xF8F8F8, 0xF9F9F9, 0xFAFAFA, 0xFBFBFB,
  0xFCFCFC, 0xFDFDFD, 0xFEFEFE, 0xFFFFFF
};
 
static GUI_CONST_STORAGE GUI_LOGPALETTE _Palzoo_800_600 = {
  256,  // Number of entries
  0,    // No transparency
  &_Colorszoo_800_600[0]
};
 
GUI_CONST_STORAGE GUI_BITMAP bmzoo_800_600 = {
  800, // xSize
  600, // ySize
  800, // BytesPerLine
  8, // BitsPerPixel
  _aczoo_800_600,  // Pointer to picture data (indices)
  &_Palzoo_800_600   // Pointer to palette
};
  • Modify codes
static GUI_CONST_STORAGE unsigned char _aczoo_800_600[] = {
to (you can rename the array)
const unsigned char zoo_800_600[] = {
  • Modify IT8951.c file, for example:
extern const unsigned char zoo_800_600[];
void IT8951DisplayExample3()
{
	IT8951LdImgInfo stLdImgInfo;
	IT8951AreaImgInfo stAreaImgInfo;
	TWord width = gstI80DevInfo.usPanelW;
	TWord high = gstI80DevInfo.usPanelH;
	TDWord i;
 
	for (i = 0;i < width*high;i++)
	{
		gpFrameBuf[i] = zoo_800_600[i];
	}
 
	IT8951WaitForDisplayReady();
 
	//Setting Load image information
	stLdImgInfo.ulStartFBAddr    = (TDWord)gpFrameBuf;
	stLdImgInfo.usEndianType     = IT8951_LDIMG_L_ENDIAN;
	stLdImgInfo.usPixelFormat    = IT8951_8BPP; 
	stLdImgInfo.usRotate         = IT8951_ROTATE_0;
	stLdImgInfo.ulImgBufBaseAddr = gulImgBufAddr;
	//Set Load Area
	stAreaImgInfo.usX      = 0;
	stAreaImgInfo.usY      = 0;
	stAreaImgInfo.usWidth  = width;
	stAreaImgInfo.usHeight = high;
 
	IT8951HostAreaPackedPixelWrite(&stLdImgInfo, &stAreaImgInfo);//Display function 2
	IT8951DisplayArea(0,0, gstI80DevInfo.usPanelW, gstI80DevInfo.usPanelH, 2);
}

Precautions

Connection

Due to updating, the hardware connection of e-Paper may be different as the picture showed, please connect the e-Paper according to the screen silk printing.

  • Example 1
20191213143317.png
  • Example 2
20191213141630.png

DIP switch

  • We recommend you to use USB, I80 and SPI interfaces
  • Whether you use USB, SPI or I80 interface, you should turn the switch to ON as below
20191213160132.png
  • If E-LINK software didn't recognize the e-Paper when you use USB interface, please check if the pins marked in red are accessible.

Codes description

  • DisplayColorPaletteExample
    • This function is used to display 16 gray bars in order.
    • This function uses 4bp mode and GC16 mode, partial refresh.
  • DisplayCharacterPatternExample
    • This function is used to draw points, lines, circles, rectangles, and characters. Supports 1bpp, 2bpp, 4bpp, 8bpp, and 1bpp method is used with A2 mode.
  • DisplayBMPExample
    • This function is used to display BMP pictures.
  • DynamicRefreshExample
    • This function is used for the A2 mode.
    • This function show you how to update e-Paper in A2 mode. With this demo, the e-Paper is updated several times and cleared in INIT mode to clear ghosts.
  • DynamicGIFExample
    • This function is used to display GIF images.
    • The GIF image is divided into seven BMP images and saved to a buffer of IT8951. e-Paper will read the BMP files in order and update them. Because the images are saved to IT8951 directly, the updated rate, in this case, is the maximum one that the e-paper could reach.
  • CheckFrameRateExample
    • This function is used to test the update rate of different modes.

About the modes

Mode Features 6inch/6inch HD 7.8inch/9.7inch/10.3inch
INIT Used to clear screen. please use it to clear screen after A2 mode Mode0 Mode0
GC16 It is used it update screen for 16 grayscale display Mode2 Mode2
A2 Can only supports Black and White color Mode4 Mode6
//basic mode definition
UBYTE INIT_Mode = 0;
UBYTE GC16_Mode = 2;
//A2_Mode's value is not fixed, is decide by firmware's LUT 
UBYTE A2_Mode = 6;
if( strcmp(LUT_Version, "M641") == 0 ){
    //6inch e-Paper HAT(800,600), 6inch HD e-Paper HAT(1448,1072), 6inch HD touch e-Paper HAT(1448,1072)
    A2_Mode = 4;
    Four_Byte_Align = true;
}else if( strcmp(LUT_Version, "M841") == 0 ){
    //9.7inch e-Paper HAT(1200,825)
    A2_Mode = 6;
}else if( strcmp(LUT_Version, "M841_TFA2812") == 0 ){
    //7.8inch e-Paper HAT(1872,1404)
    A2_Mode = 6;
}else if( strcmp(LUT_Version, "M841_TFA5210") == 0 ){
    //10.3inch e-Paper HAT(1872,1404)
    A2_Mode = 6;
}else{
    //default set to 6 as A2 Mode
    A2_Mode = 6;
}

About bpp

bpp is Bits per pixel, it is the data that show the number of bits per pixel. Currently, all the gray e-Paper supports 1bpp, 2bpp, 4bpp and 8bpp.

  • 1bpp
    • Evey pixel use 1 bit
    • It supports 2 (2^1=2) gray, it is used for A2 mode
    • Evey byte contains 8 pixels
    • Save in RAM in big-endian format
    • IT8951 use little-endian format by default, you should convert it when using.
20191219164855.png
  • 2bpp
    • Every pixel use 2 bits
    • Support 4(2^2=4) grays
    • Every byte contains 4 pixels
    • Save in RAM in big-endian format
    • IT8951 use little-endian format by default, you should convert it when using.

20191219164916.png

  • 4bpp
    • Every pixel use 4 bits
    • Support 16(2^4=16) grays
    • Every byte contains 2 pixels
    • Save in RAM in big-endian format
    • IT8951 use little-endian format by default, you should convert it when using.

20191219164949.png

  • 8bpp
    • Every pixel use 8 bits
    • Support 256(2^8=256) grays, however, IT8951 only use the high four bits, only support 16 grays.
    • Every byte contains 1 pixels
    • Save in RAM in big-endian format
    • IT8951 use little-endian format by default, you should convert it when using.

20191219165020.png

Every pixel of the original image contains 8bits (1 byte). To convert it to BMP, you can only get the hight bits. For example, if you want to get pixels for 2bpp, you can just get the hight 2 bits from 8bpp(8bits) image.

UDOUBLE Addr = X * (Paint.BitsPerPixel) / 8 + Y * Paint.WidthByte;
switch( Paint.BitsPerPixel ){
    case 8:{
        Paint.Image[Addr] = Color & 0xF0;
        break;
    }
    case 4:{
        Paint.Image[Addr] &= ~( (0xF0) >> (7 - (X*4+3)%8 ) );
        Paint.Image[Addr] |= (Color & 0xF0) >> (7 - (X*4+3)%8 );
        break;
    }
    case 2:{
        Paint.Image[Addr] &= ~( (0xC0) >> (7 - (X*2+1)%8 ) );
        Paint.Image[Addr] |= (Color & 0xC0) >> (7 - (X*2+1)%8 );
        break;
    }
    case 1:{
        Paint.Image[Addr] &= ~( (0x80) >> (7 - X%8) );
        Paint.Image[Addr] |= (Color & 0x80) >> (7 - X%8);
        break;
    }
}

Align bytes

During test, we find that when we use 1bpp mode to update the 6inch e-Paper, 6inch HD e-Paper, we should align the X (begin point) and W (width) of udpate area to four bytes (32bits), otherwse, the image cannot be displayed.

if( strcmp(LUT_Version, "M641") == 0 ){
    //6inch e-Paper HAT(800,600), 6inch HD e-Paper HAT(1448,1072), 6inch HD touch e-Paper HAT(1448,1072)
    A2_Mode = 4;
    Four_Byte_Align = true;
}else if( strcmp(LUT_Version, "M841") == 0 ){
...
}
if(Four_Byte_Align == true){
    In_4bp_Refresh_Area_Width = Panel_Width - (Panel_Width % 32);
}else{
    In_4bp_Refresh_Area_Width = Panel_Width;
}
X_Start = Min_X < 32 ? 0 : Min_X - (Min_X % 32);
Debug("X_Start:%d\r\n",X_Start);
X_End = ( Max_X + (32 - (Max_X % 32)) ) > Touch_Pannel_Area_Width ? ( Max_X - (Max_X % 32) )  : ( Max_X + (32 - (Max_X % 32)) );
Debug("X_End:%d\r\n",X_End);
Y_Start = Min_Y;
Debug("Y_Start:%d\r\n",Y_Start);
Y_End = Max_Y;
Debug("Y_Start:%d\r\n",Y_End);
Width = X_End - X_Start;
if(Width<=0){
    Width = 32;
}
Debug("Width:%d\r\n",Width);
Height = Y_End-Y_Start;
if(Height<=0){
    Height = 32;
}
Debug("Height:%d\r\n",Height);

About the speed of SPI

The CPU of Raspberry Pi 3 is different with Raspberry Pi 4

  • For Raspberry Pi, it could use maximum 16 clock divider
  • For Raspberry Pi, it could use maximum 32 clock divider
  • You can refer to the description of BCM2835 libraries about the clock divider
20191219173204.png
  • You can modify the clock divider according to the board you use
bcm2835_spi_begin();//Start spi interface, set spi pin for the reuse function
bcm2835_spi_setBitOrder(BCM2835_SPI_BIT_ORDER_MSBFIRST);//High first transmission
bcm2835_spi_setDataMode(BCM2835_SPI_MODE0);//spi mode 0
 
//bcm2835_spi_setClockDivider(BCM2835_SPI_CLOCK_DIVIDER_16);//For RPi 3/3B/3B+
bcm2835_spi_setClockDivider(BCM2835_SPI_CLOCK_DIVIDER_32);//For RPi 4B
 
/* SPI clock reference link:*/
/*http://www.airspayce.com/mikem/bcm2835/group__constants.html#gaf2e0ca069b8caef24602a02e8a00884e*/

Enhance driving capability

Sometimes, the e-Paper display abnormally because of long FPC cable, in this case, you can try to enhance the driving capability

#if(Enhance)
    Debug("Attention! Enhanced driving ability, only used when the screen is blurred\r\n");
    Enhance_Driving_Capability();
#endif
/******************************************************************************
function :  Enhanced driving capability
parameter:  Enhanced driving capability for IT8951, in case the blurred display effect
******************************************************************************/
void Enhance_Driving_Capability(void)
{
    UWORD RegValue = EPD_IT8951_ReadReg(0x0038);
    Debug("The reg value before writing is %x\r\n", RegValue);
    EPD_IT8951_WriteReg(0x0038, 0x0602);
    RegValue = EPD_IT8951_ReadReg(0x0038);
    Debug("The reg value after writing is %x\r\n", RegValue);
}
  • If you are using the USB interface with a PC, you can try to configure:
  • Read the data of 0x18000038 register
6inch-e-Paper-HAT-Manual-11.png
  • Modify the data to 602
6inch-e-Paper-HAT-Manual-12.png
  • Check the data.
6inch-e-Paper-HAT-Manual-13.png

Check whether the data of the register address 0x18000038 has been modified successfully. If the data of the address is 0x602, it means that the driving capability has been enhanced. In this state, the screen can be refreshed to avoid some situations, such as the FPC line being too long, the production batch being different, etc., resulting in a blurry display.

About VCOM

The VCOM voltages of every e-Paper panel are different and they are printed on FPC cable. Please make sure that you use the correct VCOM.