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e-Paper HAT Codes description

About the codes


We provide examples for four popular hardware platforms: Arduino UNO, Jetson UNO, Raspberry Pi, and STM32. (This is common Template for all e-Paper, some of the description/function may not be used by the e-Paper you have)
Every project is divided into hardware interface, EPD driver and the application function;
The programming languages are C\C++\python:

  • Arduino UNO:C++
  • Jetson Nano:C and python
  • Raspberry Pi:C and python
  • STM32:C

Note:
The EPD driver of C codes of Jetson Nano, Raspberry Pi, and STM32 are compatible. Except for the hardware interface, the codes are same;


C (Used for Jetson Nano、Raspberry Pi、STM32)

Hardware interface

Because of multiple hardware platforms, we package the bottom, for details of how it realizes, you go to related directory for certain codes

In file DEV_Config.c(.h):
For Raspberry Pi, the files are located in: RaspberryPi&JetsonNano\c\lib\Config

Here we use two libraries: bcm2835 and wiringPi
WiringPi library is used by default, if you want to use bcm2835 libraries, you just need to modify RaspberryPi&JetsonNano\c\Makefile file, change the lines 13 and 14 as below::

For Jetson Nano, the files are located in RaspberryPi&JetsonNano\c\lib\Config
For STM32, the files are located in STM32\STM32-F103ZET6\User\Config

  • Data type:
#define UBYTE   uint8_t
#define UWORD   uint16_t
#define UDOUBLE uint32_t
  • Module Init and Exit handle:
void DEV_Module_Init(void);
void DEV_Module_Exit(void);

Note:

1.The functions are used to set GPIP before and after driving e-Paper.

2.If the board you have is printed with Rev2.1, module enter low-ultra mode after DEV_Module_Exit(). (as we test, the current is about 0 in this mode);

  • GPIO Read/Write:
void DEV_Digital_Write(UWORD Pin, UBYTE Value);
UBYTE DEV_Digital_Read(UWORD Pin);
  • SPI Write data
void DEV_SPI_WriteByte(UBYTE Value);
EPD driver

For Raspberry Pi and Jetson Nano, epd driver are saved in:RaspberryPi&JetsonNano\c\lib\e-Paper
For STM32, the epd driver are saved in: STM32\STM32-F103ZET6\User\e-Paper



Open .h file, functions are declarated here

  • Initialization: It should be used to initialize e-Paper or wakeup e-Paper from sleep mode.
//1.54inch e-Paper、1.54inch e-Paper V2、2.13inch e-Paper、2.13inch e-Paper  V2、2.13inch e-Paper (D)、2.9inch e-Paper、2.9inch e-Paper (D)
void EPD_xxx_Init(UBYTE Mode); // Mode = 0 Initialize full refresh; Mode = 1 Initilize partial refresh 
//Other types
void EPD_xxx_Init(void);

xxx is the type of e-paper, for example, if the e-paper you have is 2inch e-Paper (D), then it should be EPD_2IN13D_Init(0) or EPD_2IN13D_Init(1); If it is 7.5inch e-Paper (B), the function should be EPD_7IN5BC_Init(). B type and C type of 7.5inch e-Paper use the same codes.

  • Clear display: This function is used to clear the e-paper to white
void EPD_xxx_Clear(void);

xxx is the type of e-Paper. For example, if the e-Paper you have is 4.2inch e-Paper, it should be EPD-4IN2_Clear()

  • Transmit a frame of image and display
//Black/White e-Paper
void EPD_xxx_Display(UBYTE *Image);
//Three colors e-Paper
void EPD_xxx_Display(const UBYTE *blackimage, const UBYTE *ryimage);


There are some exceptions:

//To partial refresh 2.13inch e-paper (D)、2.9inch e-paper (D), you should use
 void EPD_2IN13D_DisplayPart(UBYTE *Image);
 void EPD_2IN9D_DisplayPart(UBYTE *Image);


//Because controllers of 1.54inch e-Paper V2 and 2.13inch e-Paper V2 were updated, you need to use EPD_xxx_DisplayPartBaseImage to display static image and ten use EPD_xxx_displayPart() to dymatic display when partial refreshing.
void EPD_1IN54_V2_DisplayPartBaseImage(UBYTE *Image);
void EPD_1IN54_V2_DisplayPart(UBYTE *Image);
void EPD_2IN13_V2_DisplayPart(UBYTE *Image);
void EPD_2IN13_V2_DisplayPartBaseImage(UBYTE *Image);


//Because STM32103ZET5 has no enough RAM for image, therefore 7.5B、7.5C、5.83B、5.83C can only display half of the screen:'''
void EPD_7IN5BC_DisplayHalfScreen(const UBYTE *blackimage, const UBYTE *ryimage);
void EPD_5IN83BC_DisplayHalfScreen(const UBYTE *blackimage, const UBYTE *ryimage);

xxx is the type of e-Paper

  • Enter sleep mode
void EPD_xxx_Sleep(void);

Note, You should hardware reset or use initialize function to wake up e-Paper from sleep mode
xxx is the type of e-Paper

Application function

Basic drawing functions are provided here. You can find then in:
Raspbian Pi & Jetson Nano: RaspberryPi&JetsonNano\c\lib\GUI\GUI_Paint.c(.h)
STM32: STM32\STM32-F103ZET6\User\GUI\GUI_Paint.c(.h)



The fonts are saved in the directory:
Raspberry Pi & Jetson Nano: RaspberryPi&JetsonNano\c\lib\Fonts
STM32: STM32\STM32-F103ZET6\User\Fonts



  • Create a new image buffer: This function is used to create a new image with width, height, Rotate degree and its color.
void Paint_NewImage(UBYTE *image, UWORD Width, UWORD Height, UWORD Rotate, UWORD Color)
Paratemeters:
 	image : The buffer of image, this is an pointer of buffer address;
 	Width : width of the image;
 	Height: height of the image;
 	Rotate:Rotate degree;
 	Color :Initial color of the image;
  • Select image buffer: this function is used to select the image buffer. You can create multiple image buffer with last function, then select the buffer for every image.
void Paint_SelectImage(UBYTE *image)
Parameters:
 	image: The name of image buffer, it is a pointer of buffer address;
  • Set display orientation: This function is used to set the rotate degree, it is generally be used after Paint_SelectImage(). You can set the rotate degree to 0、90、180、270 degree.
void Paint_SetRotate(UWORD Rotate)
Parameters:
 	Rotate: Rotate degree, you can choose ROTATE_0、ROTATE_90、ROTATE_180、ROTATE_270 which stands for 090180270 degree repetitively.
【Note】Three figures below shows the display effect in differen degree. (0°, 90°, 180°, 270°)


  • Image mirroring: This function is used to mirror image.
void Paint_SetMirroring(UBYTE mirror)
Paramters:
 	mirror: You can set it to MIRROR_NONE、MIRROR_HORIZONTAL、MIRROR_VERTICAL、MIRROR_ORIGIN
  • Set pixel: this function is used to set the position and color of pixels in the buffer. This is the basic function of GUI.
void Paint_SetPixel(UWORD Xpoint, UWORD Ypoint, UWORD Color)
Parameters:
 	Xpoint: X-axes in buffer;
 	Ypoint: Y-axes in buffer;
 	Color : color
  • Clear: This function is used to clear the screen to certain color.
void Paint_Clear(UWORD Color)
Parameter:
 	Color:
  • Clear windows:this function is used to clear a window. It is generally used for time display.
void Paint_ClearWindows(UWORD Xstart, UWORD Ystart, UWORD Xend, UWORD Yend, UWORD Color)
Parameters:
 	Xstart: Start coordinate of X-axes of window;
 	Ystart: Start coordinate of Y-axes of window;
 	Xend: End coordinate of X-axes of window;
 	Yend: End coordinate of Y-axes of window;
 	Color:
  • Draw point: Draw a point on the position (Xpoint, Ypoint)in buffer
void Paint_DrawPoint(UWORD Xpoint, UWORD Ypoint, UWORD Color, DOT_PIXEL Dot_Pixel, DOT_STYLE Dot_Style)
Parameter:
 	Xpoint: X coordinate of point;
 	Ypoint: Y coordinate of point;
 	Color: color of point;
 	Dot_Pixel: the size of point, there are 8 sizes available;
 	 	 typedef enum {
 	 	 	 DOT_PIXEL_1X1  = 1,	// 1 x 1
 	 	 	 DOT_PIXEL_2X2  , 		// 2 X 2
 	 	 	 DOT_PIXEL_3X3  , 	 	// 3 X 3
 	 	 	 DOT_PIXEL_4X4  , 	 	// 4 X 4
 	 	 	 DOT_PIXEL_5X5  , 		// 5 X 5
 	 	 	 DOT_PIXEL_6X6  , 		// 6 X 6
 	 	 	 DOT_PIXEL_7X7  , 		// 7 X 7
 	 	 	 DOT_PIXEL_8X8  , 		// 8 X 8
 	 	} DOT_PIXEL;
 	Dot_Style: style of point. 
 	 	typedef enum {
 	 	   DOT_FILL_AROUND  = 1,		
 	 	   DOT_FILL_RIGHTUP,
 	 	} DOT_STYLE;
  • Draw line: draw a line for (Xstart, Ystart) to (Xend, Yend)
void Paint_DrawLine(UWORD Xstart, UWORD Ystart, UWORD Xend, UWORD Yend, UWORD Color, LINE_STYLE Line_Style , LINE_STYLE Line_Style)
Parameter:
 	Xstart: Start coordinate of X-axes of line;
 	Ystart: Start coordinate of Y-axes of line;
 	Xend: End coordinate of X-axes of line;
 	Yend: End coordinate of Y-axes of line;
 	Color:  color of line
 	Line_width: the width of line, 8 sizes are avalilable;
 	 	typedef enum {
 	 	 	 DOT_PIXEL_1X1  = 1,	// 1 x 1
 	 	 	 DOT_PIXEL_2X2  , 		// 2 X 2
 	 	 	 DOT_PIXEL_3X3  ,		// 3 X 3
 	 	 	 DOT_PIXEL_4X4  ,		// 4 X 4
 	 	 	 DOT_PIXEL_5X5  , 		// 5 X 5
 	 	 	 DOT_PIXEL_6X6  , 		// 6 X 6
 	 	 	 DOT_PIXEL_7X7  , 		// 7 X 7
 	 	 	 DOT_PIXEL_8X8  , 		// 8 X 8
 	 	} DOT_PIXEL;
 	 Line_Style: Style of the line;
 	 	typedef enum {
 	 	 	 LINE_STYLE_SOLID = 0,
 	 	 	 LINE_STYLE_DOTTED,
 	 	} LINE_STYLE;
  • Draw rectangle: Draw a rectangle from (Xstart, Ystart) to (Xend, Yend).
void Paint_DrawRectangle(UWORD Xstart, UWORD Ystart, UWORD Xend, UWORD Yend, UWORD Color, DOT_PIXEL Line_width, DRAW_FILL Draw_Fill)
Parameter:
 	Xstart: Start coordinate of X-axes of rectangle
 	Ystart: Start coordinate of Y-axes of rectangle
 	Xend: End coordinate of X-end of rectangle
 	Yend: End coordinate of Y-end of rectangle
 	Color: color of rectangle
 	Line_width: The width of edges, 8 sides are available;
 	 	typedef enum {
 	 	 	 DOT_PIXEL_1X1  = 1,	// 1 x 1
 	 	 	 DOT_PIXEL_2X2  , 		// 2 X 2
 	 	 	 DOT_PIXEL_3X3  ,		// 3 X 3
 	 	 	 DOT_PIXEL_4X4  ,		// 4 X 4
 	 	 	 DOT_PIXEL_5X5  , 		// 5 X 5
 	 	 	 DOT_PIXEL_6X6  , 		// 6 X 6
 	 	 	 DOT_PIXEL_7X7  , 		// 7 X 7
 	 	 	 DOT_PIXEL_8X8  , 		// 8 X 8
 	 	} DOT_PIXEL;
 	Draw_Fill: set the rectangle full or empty.
 	 	typedef enum {
 	 	 	 DRAW_FILL_EMPTY = 0,
 	 	 	 DRAW_FILL_FULL,
 	 	} DRAW_FILL;
  • Draw circle:Draw a circle, use (X_Center Y_Center) as center;
void Paint_DrawCircle(UWORD X_Center, UWORD Y_Center, UWORD Radius, UWORD Color, DOT_PIXEL Line_width, DRAW_FILL Draw_Fill)
Parameter:
 	X_Center: X coordinate of center
 	Y_Center: Y coordinate of center
 	Radius:Radius of circle
 	Color: color of circle
 	Line_width: width of circle, 8 sizes are avalilable
 	 	typedef enum {
 	 	 	 DOT_PIXEL_1X1  = 1,	// 1 x 1
 	 	 	 DOT_PIXEL_2X2  , 		// 2 X 2
 	 	 	 DOT_PIXEL_3X3  ,		// 3 X 3
 	 	 	 DOT_PIXEL_4X4  ,		// 4 X 4
 	 	 	 DOT_PIXEL_5X5  , 		// 5 X 5
 	 	 	 DOT_PIXEL_6X6  , 		// 6 X 6
 	 	 	 DOT_PIXEL_7X7  , 		// 7 X 7
 	 	 	 DOT_PIXEL_8X8  , 		// 8 X 8
 	 	} DOT_PIXEL;
 	Draw_Fill: style of circle
 	 	typedef enum {
 	 	 	 DRAW_FILL_EMPTY = 0,
 	 	 	 DRAW_FILL_FULL,
 	 	} DRAW_FILL;
  • Draw character (ASCII): Set(Xstart Ystart) as letf-top point, draw a ASCII character.
void Paint_DrawChar(UWORD Xstart, UWORD Ystart, const char Ascii_Char, sFONT* Font, UWORD Color_Foreground, UWORD Color_Background)
Parameter:
 	Xstart: X coordinate of left-top pixel of character;
 	Ystart: Y coordinate of left-top pixel of character;
 	Ascii_Char:Ascii character;
 	Font: 5 fonts are available;
 	 	font8:5*8
 	 	font12:7*12
 	 	font16:11*16
 	 	font20:14*20
 	 	font24:17*24
 	Color_Foreground: color of character;
 	Color_Background: color of background;
  • Draw String: Set point (Xstart Ystart) as the left-top pixel, draw a string.
void Paint_DrawString_EN(UWORD Xstart, UWORD Ystart, const char * pString, sFONT* Font, UWORD Color_Foreground, UWORD Color_Background)
Parameters:
 	Xstart: X coordinate of left-top pixel of characters;
 	Ystart: Y coordinate of left-top pixel of characters;
 	pString;Pointer of string
 	Font: 5 fonts are available:
 	 	font8:5*8
 	 	font12:7*12
 	 	font16:11*16
 	 	font20:14*20
 	 	font24:17*24
 	Color_Foreground: color of string
 	Color_Background: color of background
  • Draw Chinese charactgers: this function is used to draw Chinese fonts based ON GB2312 fonts.
void Paint_DrawString_CN(UWORD Xstart, UWORD Ystart, const char * pString, cFONT* font, UWORD Color_Foreground, UWORD Color_Background)
Parameter:
 	Xstart: Coordinate of left-top pixel of characters;
 	Ystart: Coordinate of left-top pixel of characters;
 	pString:Pointer of string;
 	Font: GB2312 fonts:
 	 	font12CN:11*21(ascii)16*21 (Chinese)
 	 	font24CN:24*41(ascii)32*41 (Chinese)
 	Color_Foreground: color of string
 	Color_Background: color of background
  • Draw number: Draw a string of numbers, (Xstart, Ystart) is the left-top pixel.
void Paint_DrawNum(UWORD Xpoint, UWORD Ypoint, int32_t Nummber, sFONT* Font, UWORD Color_Foreground, UWORD Color_Background)
Parameter:
 	Xstart: X coordinate of left-top pixel;
 	Ystart: Y coordicate of left-to pixel;
 	Nummber:the numbers displayed. the numbers are saved in int format, the maximum is 2147483647;
 	Font: 5 fonts are available:
 	 	font8:5*8
 	 	font12:7*12
 	 	font16:11*16
 	 	font20:14*20
 	 	font24:17*24
 	Color_Foreground: color of font;
 	Color_Background: volor of background;
  • Display time:Display time, (Xstart, Ystart) is the left-top pixel. This function is used for e-Paper which supports partial refresh
void Paint_DrawTime(UWORD Xstart, UWORD Ystart, PAINT_TIME *pTime, sFONT* Font, UWORD Color_Background, UWORD Color_Foreground)
Parameter:
 	Xstart: X coordinate of left-top pixel of character;
 	Ystart: Y coordinate of left-top pixel of character;
 	pTime:pointer of time displayed;
 	Font: 5 fonts are available;
 	 	font8:5*8
 	 	font12:7*12
 	 	font16:11*16
 	 	font20:14*20
 	 	font24:17*24
 	Color_Foreground: color of fonts
 	Color_Background: color of background
  • Draw image:send image data of bmp file to buffer
void Paint_DrawBitMap(const unsigned char* image_buffer)
Parameter:
 	image_buffer: adrress of image data in buffer
  • Read local bmp picture and write it to buffer

Linux platform like Jetson Nano and Raspberry Pi support to directly operate bmp pictures
Raspberry Pi & Jetson Nano:RaspberryPi&JetsonNano\c\lib\GUI\GUI_BMPfile.c(.h)

UBYTE GUI_ReadBmp(const char *path, UWORD Xstart, UWORD Ystart)
Parameter:
	path:The path of BMP pictures
 	Xstart: X coordination of left-top of picture, default 0;
 	Ystart: Y coordination of left-top of picture, default 0;
Testing code

In the above part, we describe about the tree structures of linux codes, here we talk about the testing code for user.
Raspberry Pi & Jetson Nano: RaspberryPi&JetsonNano\c\examples;
The codes in exampleas are testing code, you can modify the definition in main.c file for different types of e-Paper.



For example, if you want to test 7.5inch e-paper, you need to delete the "//" symbol on line 42.

// EPD_7in5_test();

change it to

EPD_7in5_test();

Then compile it again and run

make clean
make
sudo ./epd

STM32:STM32\STM32-F103ZET6\User\Examples;
testing codes are saved in this folder, open project, and then modify the definition stentences in main.c file;
Open project:STM32\STM32-F103ZET6\MDK-ARM\epd-demo.uvprojx



For example, if you want to test 7.5inch e-paper, you should delete the "//" symble of on line 96

// EPD_7in5_test();

Change it to

EPD_7in5_test();

Then re-compile project and donwload it

Python(Used for Jetson Nano\Raspberry Pi)

Supports python2.7 and python3
python is easy to use than c codes
Raspberry Pi & Jetson Nano: RaspberryPi&JetsonNano\python\lib\



epdconfig.py

  • Initialize module and exit handle:
def module_init()
def module_exit()
Note:

1.The functions are used to set GPIP before and after driving e-Paper.

2.If the board you have is printed with Rev2.1, module enter low-ultra mode after Module_Exit(). (as we test, the current is about 0 in this mode);

  • GPIO Read/Write:
def  digital_write(pin, value)
def  digital_read(pin)
  • SPI write data
def spi_writebyte(data)
epdxxx.py(xxx is the type of the e-Paper)

  • Initialize e-paper: this function should be used at the beginning. It can also be used to wake up e-Paper from Sleep mode.
For 1.54inch e-Paper、1.54inch e-Paper V2、2.13inch e-Paper、2.13inch e-Paper  V2、2.13inch e-Paper (D)、2.9inch e-Paper、2.9inch e-Paper (D)
def init(self, update) # update should be lut_full_update or lut_partial_update
Other types:
def init(self)
  • Clear e-paper: This function is used to clear e-Paper to white;
def Clear(self)
def Clear(self, color) # Some types of e-Paper should use this function to clear screen
  • Convert image to arrays
def getbuffer(self, image)
  • Transmit one frame of imgae data and display
#For two-color e-paper
def display(self, image)
#For three-color e-Paper
def display(self, blackimage, redimage)
 
There are several excepation:<br />
For flexible e-Paper 2.13inch e-paper (D)、2.9inch e-paper (D), the partial refresh should use
def DisplayPartial(self, image)
#Because that controllers of 1.54inch e-paper V2、2.13inch e-paper V2 are updated, when partial refresh, they should first use displayPartBaseImage() to display static background, then use displayPart() to dynamaticlly display.
def displayPartBaseImage(self, image)
def displayPart(self, image)
  • Enter sleep mode
def sleep(self)
epd_xxx_test.py(xxx is type of e-paper)

python examples are saved in directory:
Raspberry Pi & Jetson Nano:RaspberryPi&JetsonNano\python\examples\



If the python installed in your OS is python2, you should run examples like below:

sudo python epd_7in5_test.py

If it is python3, the commands should be:

sudo python3 epd_7in5_test.py

Note: You can change epd_7inch5_test.py to the certain type you use.

Orientation
To rotate the display, you can use transpose function
blackimage = blackimage.transpose(Image.ROTATE_270) 
redimage = redimage.transpose(Image.ROTATE_270)
#Supports OTATE_90, ROTATE_180, ROTATE_270
【Note】Three figures below shows the display effect in different degree. (0°, 90°, 180°, 270°)

Arduino

Because Arduino doesn't have full RAM for display dynamatic image, we don't provide other functions for it. If you want to use Arduino, we recommend you to use Waveshare e-paper Sheild.