9.7inch e-Paper HAT

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9.7inch e-Paper raw Panel
9.7inch-ePaper.JPG

1200 × 825, 9.7inch EPD panel without the driver board
9.7inch e-paper HAT
9.7inch-e-Paper-HAT.JPG

1200 × 825, 9.7inch EPD HAT for Raspberry Pi, USB/SPI/I80/I2C interface
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Introduction

  • 9.7inch EPD (Electronic Paper Display) HAT for Raspberry Pi, 1200 × 825 resolution, 16 gray scale, USB/SPI/I80/I2C interface.
  • It has the advantages of low power consumption, wide viewing angle, and clear display under direct sunlight. It is often used in display applications such as shelf labels and industrial instruments.
More

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.
  • Compatible with Raspberry Pi Zero/Zero W/Zero WH/2B/3B/3B+.
  • USB/SPI/I80/I2C interface, for connecting with host boards like Raspberry Pi/Nucleo, etc.
  • Comes with development resources and manual (examples for Raspberry Pi/STM32).

Specifications

  • Operating voltage: 5V
  • Interface: USB/SPI/I80/I2C
  • Outline dimension: 218.8mm × 156.425mm × 1.15mm
  • Display size: 202.8mm × 139.425mm
  • Dot pitch: 0.169 × 0.169
  • Resolution: 1200 × 825
  • Display color: black, white
  • Grayscale: 2-16 (1-4 bit)
  • Full refresh time: <1s
  • Total refresh power: 0.6W (typ.)
  • Total standby power: 0.3W (typ.)
  • Viewing angle: >170°


16-grey-scale2.jpg

Working principle

This product is an E-paper device adopting the image display technology of Microencapsulated Electrophoretic Display, MED. The initial approach is to create tiny spheres, in which the charged color pigments are suspended in the transparent oil and would move depending on the electronic charge. The E-paper screen display patterns by reflecting the ambient light, so it has no background light requirement. Under ambient light, the E-paper screen still has high visibility with a wide viewing angle of 180 degrees. It is the ideal choice for E-reading. (Note that the e-Paper cannot support updating directly under sunlight).

How to use

Working with Windows PC

  • Connect 9.7inch e-paper to IT8951 driver board as below.
9.7inch-e-Paper-HAT-Manual-09.jpg
  • Connect driver board to PC by USB cable.
  • Download and open test software. E-LINK-TCON-DEMO
  • Click connect as below.
9.7inch-e-Paper-HAT-Manual-10.jpg
  • Check option "AutoSet", then click "Open File" to open one picture for display. The browse diagram will be opened, and you should click "OK".
9.7inch-e-Paper-HAT-Manual-11.jpg
  • Click "display" to refresh the picture.
9.7inch-e-Paper-HAT-Manual-12.jpg

Note: If you want to use the USB interface to develop the e-Paper on Windows, you need to contact the Waveshare team and sign the NDA before you can get the E-LINK-TCON-DEMO source code.
Note: Currently not available for individual users.

Working with Raspberry Pi

  • Hardware connection
9.7inch-e-Paper-HAT-Manual-13.jpg
You can also connect 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 status pin (Low when busy)
  • Make sure you have switched the sail switch to SPI mode.
9.7inch-e-Paper-HAT-Manual-14.jpg

Copy the library you download to Raspberry Pi and install it with the commands below. You can also follow the instruction on its website above.

tar zxvf bcm2835-1.xx.tar.gz
cd bcm2835-1.xx
./configure
make
sudo make check
sudo make install
  • Download Demo code and copy it to your Raspberry Pi. Extract and run it with the commands below in your Raspberry Pi.
git clone https://github.com/waveshare/IT8951-ePaper.git
cd IT8951-ePaper/Raspberry
sudo make clean
sudo make -j4

heck 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 -2.51 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

Because IT8951 will cost a big size of RAM, some STM32 cannot support without an external SDRAM device. So we here use Open429I as a test board, Open429I integrates IS42S16400J (64-MBIT) SDRAM, and has full memory to drive the 9.7inch e-paper.

Working with STM32, you can use SPI, I80 or I2C interface. SPI is simple and needs a few GPIO, its speed can also meet the requirement of most applications. I80 is also simple and fast, however, it needs to use lots of GPIO. I2C is very slow, which we don't recommend.

SPI

1) Hardware connection

IT8951 STM32 Description
5V 5V 5V Power input
GND GND Ground
MISO PE13 Data output
MOSI PE14 Data input
SCK PE12 Clock input
CS PE11 Chip select (Low active)
RST PC5 Reset (Low for reset)
HRDY PA7 BUSY state output (Low for busy)

2) Set the switch to SPI mode

9.7inch-e-Paper-HAT-Manual-14.jpg

3) Download the demo code to refresh the picture

You can download the demo code here

Open the project with Keil :Open429I-C-IT8951-Demo\Project\9.7-IT8951\MDK-ARM\Project.uvproj

Compile it, then open IT8951.h, and check if SPI mode is enabled. Compile it again and download it to your board. After downloading, the

9.7inch-e-Paper-HAT-Manual-15.jpg

The information will be printed as below (115200, 8N1)

9.7inch-e-Paper-HAT-Manual-16.jpg

I80

1) Hardware connection

IT8951 STM32 Description
Vcc 5V 5V Power input
GND GND Ground
DBUS0~DBUS15 PB0~PB15 Data pins
HWE PC1 Write enable (Low active)
D/C PC7 Data/Command (Low for command)
CSEL PC6 Chip select (Low active)
HRD PC3 Read eenable (Low for active)
RST PC0 Reset (Low for reset)
BUSY PA7 Busy state output (Low for busy)

2) Set the switch to I80 mode

9.7inch-e-Paper-HAT-Manual-17.jpg

3) Display with demo code

You can download the demo code here

Open the project and change set the interface to I80.

9.7inch-e-Paper-HAT-Manual-18.jpg

Display pictures

For easy porting our demo code, we display picture with data matrix instead of file system.

We should first convert BMP picture to data matrix (arrays), and use it in demo code.

1) Prepare a BMP image, resize the picture to 1200*825 (the resolution of this e-Paper)

2) Open BMP convert software, Click File->Open..-> to open the picture as below:

9.7inch-e-Paper-HAT-Manual-19.jpg

3) Click Image -> Convert to ->Gray256(8 BPP)

9.7inch-e-Paper-HAT-Manual-20.jpg

4) Click File ->Save As... ->Choose "C" bitmap file (*.c) -> input file name and click Save.

5) Choose 8 bit per pixel, click OK. A C file will be saved to your PC

9.7inch-e-Paper-HAT-Manual-21.jpg

6) Add the C file to keil project, detect unusable 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                                                   *
* Dimensions:  1200 * 825                                            *
* 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;
 
/*********************************************************************
*
*       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[] = {
  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 = {
  256,  // Number of entries
  0,    // No transparency
  &_Colorszoo[0]
};
 
GUI_CONST_STORAGE GUI_BITMAP bmzoo = {
  1200, // xSize
  825, // ySize
  1200, // BytesPerLine
  8, // BitsPerPixel
  _aczoo,  // Pointer to picture data (indices)
  &_Palzoo   // Pointer to palette
};

7) Modify the codes

static GUI_CONST_STORAGE unsigned char _aczoo[] = {

to this one. (You can change the name of the array to every one you like)


const unsigned char zoo_1200_825[] = {

8) Modify related codes in IT8951.C as below

extern const unsigned char zoo_1200_825[];
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_1200_825[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

New Features

  • 1. Using 4bpp to refresh the 16-level grayscale image, the amount of SPI transmission data is reduced to half of the original one, avoiding the waste of RAM and transmission time caused by the previous version using 8bpp to refresh the 16-level grayscale image.
  • 2. The SPI transmission speed is doubled, which is valid in the 3rd generation of Raspberry Pi, but ineffective in the 4th generation of Raspberry Pi due to the increase in CPU frequency.
  • 3. The time interval for refreshing the picture is reduced to 1/4 of the original. It is measured that the previous version of the program uses GC16 mode to refresh a BMP picture with 16-level grayscale in full screen to 10.3inch e-Paper (D). It takes about 10S. And this routine only needs about 3S.
  • 4. Avoid the memory leak caused by the previous version opening the BMP file after allocating the cache but not releasing it.
  • 5. Add 1bpp, 2bpp, 4bpp, 8bpp mode support.
  • 6. Add the A2 mode refresh demo, you can feel the A2 mode refresh speed.
  • 7. Add support for drawing dots, lines, circles, rectangles, writing characters, etc., supports grayscale selection of characters and patterns, supports 1bpp, 2bpp, 4bpp, 8bpp, if you choose 1bpp, it also supports A2 mode refresh.
  • 8. Add 1bpp, 2bpp, 4bpp, and 8bpp refresh support for bmp pictures, if you choose 1bpp, it also supports A2 mode refresh.
  • 9. Add a demo for displaying GIF pictures, which can write multiple pictures into the IT8951 cache, and directly swipe the data of different addresses in the cache into the ink screen for display, eliminating the data transmission process between RPi and IT8951, refresh frame rate up to 7fps.
  • 10. Add a frame rate test routine, which is convenient for testing and refreshing areas of different sizes, 1bpp, 2bpp, 4bpp, 8bpp, and A2 mode, GC16 mode, and refreshed frame rate.
  • 11. Support to enhance the driving ability to avoid partial blurring of the screen display in some cases.
  • 12. Support 4-byte alignment for 6inch ePaper HAT and 6inch HD ePaper HAT, to avoid abnormal display during 1bp refresh.
  • 13. You need to input VCOM when the demo is running, and it will be completely white when the routine is running to protect the screen and prolong its life of the screen.
  • 14. Optimize the program structure, reduce the coupling of the program, standardize some functions, and name variables.

Codes

Locally refresh 16 grayscale bars from light to dark grayscale in turn

  • Function name:DisplayColorPaletteExample
  • This demo demonstrates how to refresh 16 grayscale bars from light to dark grayscale in turn with 4bp and GC16.

Draw Dots, Lines, Circles, Rectangles and characters

  • Function name: DisplayCharacterPatternExample
  • This demo demonstrates how to draw dots, lines, circles and characters, supports 1bpp, 2bpp, 4bpp, and 8bpp. If you use 1bpp, it also supports A2 mode to refresh.

Display BMP Picture

  • Function name: DisplayBMPExample
  • This demo demonstrates how to refresh a BMP picture, supports 1bpp, 2bpp, 4bpp and 8bpp. If you use 1bpp, it also supports A2 to refresh.

A2 Mode Refresh Example

  • Function name: DynamicRefreshExample
  • This demo demonstrates how to use A2 mode to refresh. In this demo, the refresh area will be refreshed several times, and the area of the refresh area will gradually become larger. After refreshing several times, an afterimage will appear. The afterimage will be cleared using INIT mode. Through this demo, you can intuitively feel the refresh speed of A2 mode.

Display GIF Picture

  • Function name: DynamicGIFExample
  • This Demo demonstrates how to refresh a GIF image. In this demo, a GIF image is divided into 7 bmp images in advance, and the 7bmp images are written to the cache of a continuous address of IT8951 first. During display, the image data will be read from the cache of the corresponding address of IT8951 in turn and refreshed on the e-paper screen. Because there is no process of data transmission between RPi and IT8951, the refresh speed will be very fast. This Demo also demonstrates the limit speed of the IT8951 refreshing the ink screen is about 7.

Test frame rate

  • Function name: CheckFrameRateExample
  • This demo is for testing: when refreshing areas of different sizes, 1bpp, 2bpp, 4bpp, 8bpp, as well as A2 mode, GC16 mode, and refreshed frame rate, in this demo, the time to refresh 10 frames of images will be automatically counted, and Frame rate (fps) is automatically calculated.

Related Description

Mode Description

IT8951 has flashed different firmware for different resolution screens. Different firmware has different refresh modes. See the mode description for details. The modes used in the demo are: INIT mode, GC16 mode, and A2 mode.
Below is a brief description of the relevant modes:

Mode Features 6inch/6inch HD 7.8inch/9.7inch/10.3inch
INIT is used to erase the display content and clear the screen. It is recommended to use INIT mode to clear the screen after multiple A2 mode refreshes. Mode0 Mode0
GC16 Use 16-level grayscale to update the screen display content, and the display effect is the best. Mode2 Mode2
A2 Can only update black and white 2-level grayscale, but the refresh speed is the fastest. 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 interafce with 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

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.

Resources

Schematic

Demo code

Datasheet

Software

Other documents

Related Resources

Notice:
The projects listed are all made and shared by the project owners, Waveshare isn't responsible for project either the update.

This is a post in Arduino Form about our SPI e-Paper thanks to ZinggJM, maybe you want to refer to.
This is the Inkycal project for reference.

FAQ

Questions About Software & Hardware

 Answer:
The most likely reason for not being able to print the picture is that the wires are not connected correctly. Please check the wiring. Due to the different batches of products, the wiring method may not be exactly the same as the picture. Please refer to the cable and 1 and 40 on the silk screen. As shown in the red line in the figure below:

Faqe-link.png

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 Answer:
1. Replace the Micro USB cable with good quality. There are many USB cables on the market that have too much voltage drop, which will cause the USB interface to fail to enumerate normally.

2. Try changing the USB interface. It is recommended to use the USB interface on the back of the PC. Relatively speaking, the power supply current will be larger.
3. Turn the DIP switch to the end. During shipping, the DIP switches may be loosened, and the floating configuration pins cannot put the IT8951 into USB mode.

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 Answer:
Click connect. The following information will be displayed normally (different models will display different information):

Connect.png
If you fail to refresh, check whether the hard link is normal, use the USB port on the back of the PC (most of the USB ports on the front of the PC have weak power supply capability), and replace the e-paper test. Note: Do not plug and unplug the e-paper with power on, otherwise the driver board and e-paper may be damaged.

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Questions About Screen

 Answer:
  • 【Operating condition】Temperature range: 0~50°C; Humidity range: 35%~65%RH
  • 【Storage condition】Temperature range: below 30°C; Humidity range: below 55%RH; Maximum storage time: 6 months
  • 【Transportation condition】Temperature range:-25~70°C; Maximum shipping time: 10 days
  • 【After unpacking】Temperature range: 20°C±5°C; Humidity range: 50±5%RH; Maximum storage time: Assembled within 72 hours

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 Answer:
  • Refresh mode:
    • Full refresh: The e-ink screen will flicker several times during refreshing (the flicking times depends on the refresh time), and the flicker is to remove the ghosting to achieve the best display effect.
    • Partial refresh: The e-ink screen has no flickering effect during refreshing. Users who use partial flashing should pay attention to performing a full flashing operation to remove the ghosting after refreshing several times, otherwise, the ghosting problem will become more and more serious, or even damage the screen. (At present, only some black and white e-ink screens support local brushing, please refer to the product page for details).
  • Refresh frequency:
    • During use, it is recommended that customers set the refresh interval of the e-ink screen to at least 180 seconds. (Except for products that support the partial refreshing function)
    • During the standby process (that is, after the refresh operation), it is recommended that the customer set the e-ink screen to sleep mode, or power off (the power supply part of the ink screen can be disconnected with an analog switch) to reduce power consumption and prolong the life of the e-ink screen. (If some e-ink screens are powered on for a long time, the screen will be damaged beyond repair.)
    • During the use of the e-ink screen, it is recommended that customers update the display screen at least every 24 hours. (If the screen keeps the same picture for a long time, there will be a burn-in situation that is difficult to repair).
  • Application scenarios:
    • The e-ink screen is recommended for indoor use. If it is used outdoors, it is necessary to prevent the e-ink screen from being exposed to direct sunlight, and at the same time, it is necessary to take ultraviolet protection measures, because charged particles will dry out under strong light for a long time, resulting in loss of activity and failure to refresh. This situation is irreversible. When designing electronic ink screen products, customers should pay attention to determine whether the use environment meets the requirements of electronic ink screens.

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 Answer:
Ideally, with normal use, it can be refreshed 1,000,000 times (1 million times).

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 Answer:
Power on the development board for a long time, after each refresh operation, it is recommended to set the screen to sleep mode or directly power off the processing, otherwise, the screen may burn out when the screen is in a high voltage state for a long time.

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 Answer:
Yes, but you need to re-initialize the electronic paper with software.

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Support

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