E-paper for Arduino Use

Working with Arduino

The demo code provide are bassed on Arduino UNO. If you want to use other Arduino board, you may need to change the connection even porting the codes yourself.

Hardware connection

Connect to Arduino UNO

e-Paper	Arduino
Vcc	5V
GND	GND
DIN	D11
CLK	D13
CS	D10
DC	D9
RST	D8
BUSY	D7

Install Arduino IDE

• Go to arduino IDE, and download the IDE
  
• Install it according to the guide of Arduino website.
  
• Open the IDE software after installing.
  

Run examples

• Download the deme codes and unzip it. Open the Arduino examples (~/Arduino/…)
  
• Open 2.13inch project
  
• Open the project and set the board to Arduino UNO
  
• Select the correct COM port
  
• Build and upload the codes to board
  

【Note】Because the flash of Arduino UNO is small, we recommend you use MEGA2560 if you use the big size e-Paper

Code Description

Files

Use 2.13inch e-Paper as example, open the folder of epd2in13 v2

epd2in13.ino：The project file
epd2in13.cpp(.h):EPD driver of e-Paper
epdif.cpp(.h): Hardware interface, functions for GPIO and SPI ;
font8.cpp、font12.cpp、font16.cpp、font20.cpp、font24.cpp、fonts.h：为不同大小字符的模；
imagedata.cpp(.h)：Image data, which is pre-coverted data for display directly.
The codes are include three parts: Bottom hardware interface, middle EPD driver and application functions.程；

Bottom hardware interface

hardware interfaces are defined in epdif.cpp(.h) file

Write GPIO

void DigitalWrite(int pin, int value)

The first parameter is GPIO, and second parameter is level

Read GPIO

int DigitalRead(int pin)

The parameter is GPIO, and return value is level

Delay

DelayMs(unsigned int delaytime)

Delay time, unit is ms

SPI transmit data

SpiTransfer(unsigned char data)

Type of parameter is char

Hardware initailze

int IfInit(void)

The initialize function of SPI, input/ouptu are packaged here。

Middle EPD driver

Instantiate e-Paper class

The Arduino codes is based on C++, should instantiate e-Paper class is necessary.

Epd epd;

Initialize e-Paper, it should be used to initialize e-Paper or wakeup e-Paper from sleep mode.

• 2.13inch e-Paper，2.9inch e-Paper

epd.Init(lut_full_update); //Fully update
epd.Init(lut_partial_update); //Partial update

• 4.2inch e-Paper

epd.Init();

Clear, clear the e-Paper to white

epd.clear();

In some of project, the operation is divided to two part, they work in the same way

epd.ClearFrameMemory(0xFF); 
epd.DisplayFrame();//Display it

Transmit one frame of image and display

void Display(const unsigned char* frame_buffer);
void DisplayFrame(const unsigned char* frame_buffer_black, const unsigned char* frame_buffer_red); //Three color e-Paper

Sleep

epd.Sleep();

Set the e-Paper enter sleep mode. The consumption of the e-Paper will be reduced. However, you still need to update the display periodically to avoid ghost problem.

Application functions

The drawing functions are defined in this part.
The coordination of the image buffer：

The functions are defined in epdpaint.h file

Initailze image buffer

Paint(unsigned char* image, int width, int height);

The first parameter is image buffer, the second one is the width of the picture, and the third one is the height.

Paint paint(image, 0, 0);    // width should be the multiple of 8

The second and third parameters are set to 0, you can re-configure them with functions below:

Set the width, height, rotate degree.

int  GetWidth(void); //Get the width
void SetWidth(int width);//Set the width
int  GetHeight(void);//Get the height
void SetHeight(int height);//Set the height
int  GetRotate(void);//Get the degree
void SetRotate(int rotate);//Set the rotate degree

Get the image data

unsigned char* GetImage(void);

Draw circle

void DrawPixel(int x, int y, int colored);

Coordination（x,y）

Draw characater

void DrawCharAt(int x, int y, char ascii_char, sFONT* font, int colored);

Set（x,y）as the start point, draw characters ascii_char, set the fonts as font, color is colored.

Draw string

void DrawStringAt(int x, int y, const char* text, sFONT* font, int colored);

Set（x,y）as the start point, draw the string text, font is font，color is colored

Draw line

void DrawLine(int x0, int y0, int x1, int y1, int colored);

Use （x0,y0）as start point, （x1,y1） as end point;

Draw cross line

void DrawHorizontalLine(int x, int y, int width, int colored);

Set（x0,y0）as start points，draw a line, the widht is width, and color is colored</ br>

Draw a vertical line

void DrawVerticalLine(int x, int y, int height, int colored);

Use（x0,y0） as start point, draw a vertical line, width is height and color is colored./ br>

Draw a empty rectangle

void DrawRectangle(int x0, int y0, int x1, int y1, int colored);

User（x0,y0） as start point,（x1,y1）is end point, draw a rectangel, color of edges are colored.

Draw a full rectangle

void DrawFilledRectangle(int x0, int y0, int x1, int y1, int colored);

Use（x0,y0）as start point, （x1,y1） is end point, draw a rectange, filled it with color: colored

Draw an empty circle

void DrawCircle(int x, int y, int radius, int colored);

Use （x,y）as center，draw a empty circle with radius, color is colored

Draw a full circle

void DrawFilledCircle(int x, int y, int radius, int colored);

Use （x,y）as center, draw a circle, radius is radius, filled with color: colored