A lib to handle a E-Paper display from Pervasive Displays. There is a interface board from Embedded Artists. The lib can handle graphic and text drawing and is using external fonts.

Dependents:   epaper_mbed_130411_KL25Z epaper_mbed_test epaper_KL25Z_2 test_he10 ... more

/media/uploads/dreschpe/epaper.jpg

The E-Paper display from Pervasive Displays with a interface board is available from Embedded Artists : http://www.embeddedartists.com/products/displays/lcd_27_epaper.php The 2.7 inch display have 264*176 pixel, monochrome.

Technology

You can look at the webside from Pervasive to see how the display works. http://www.pervasivedisplays.com/technology/home

This type of display have ultra low power consumption - due to its bi-stable nature. It requires only very little power to update the display and needs no power to maintain an image. You can disconnect the display - the image is still there. The viewing angle is like real paper - near 180°.

There are also some disadvantages of this technology. To change the image, we have to rewrite the full display in 4 steps. Invert, clear, invert new, new image. This process is visible and take a while -2s at room temperature. If it gets colder the display reacts slower and the interface timing has to be slow down. To compensate this, there is a LM75 temp sensor on the interface board. We also need ram to double buffer the display. 264 * 176 / 8 = 5808 Byte. To double buffer we need 11616 byte of ram. This is no problem for most mbed devices, but it will not run on the LPC11U24 or LPC800-MAX.

Interface

The graphic data is transferred to the display via spi. The maximum speed is 12Mhz. There are also some control signal and the I2C for the temperature sensor. Together we need 12 signals.

Displaymbed LPC1768mbed KL25Zsignal type
1 GNDGNDGNDGND
2 3V3VOUTP3V33.3 V power
3 SCKp7PTD1SCK
4 MOSIp5PTD2MOSI
5 MISOp6PTD3MISO
6 SSELp8PTC17GPIO
7 Busyp13PTA16GPIO
8 Borderp10PTD6GPIO
9 SCLp27PTE1SCL
10 SDAp28PTE0SDA
11 PWMp26PTD4PWM
12 Resetp12PTA17GPIO
13 Power controlp9PTD7GPIO
14 Dischargep11PTE31GPIO

Software

Fonts

How to get nice looking fonts ?

To print characters to a graphic screen we need a font. To code a font by paper is ok for a small lcd, but for a 264*176 pixel display we need bigger fonts. A 12*12 pixel font is readable, but it a lot of work to construct it by hand.

Fonts can be made with the GLCD Font Creator also from http://www.mikroe.com .

With this program you can load a window font and convert it into a c-array. To use this Font with my lib you have to add 4 parameter at the beginning of the font array. - the number of byte / char - the vertial size in pixel - the horizontal size in pixel - the number of byte per vertical line (it is vertical size / 8 ) You also have to change the type of array to char[]. After that you can switch between different fonts with set_font(unsigned char* font); The horizontal size of each character is also stored in the font. It look better if you use bigger fonts or italic. The letter M is wider than a l.

Here are some Fonts from me : http://mbed.org/users/dreschpe/code/TFT_fonts/

The small made for the mbed lab board can also be used : http://mbed.org/users/dreschpe/code/LCD_fonts/

And from Peter Holzleitner : http://mbed.org/users/pholzleitner/code/SourceCodePro31-SB/

Text commands :

You can use the claim() function to redirect the output to stdout or stderr to the display. After claim(stdout) you can simply use the printf function without the classname to print to the display. All other printf from other libs are also redirected to the display if you use this.

  • printf(...); print text and variables to the buffer with format options.
  • locate(x,y); function is used to setup the cursor position. x,y are the pixel position.

Graphics

Graphic commands :

  • cls(); Fill the screen with background color
  • pixel(x,y,color); set a single pixel at x,y with 1 : black or 0 : white
  • line(x0,y0,x1,y1,color); draw a line from x0,y0 to x1,y1 with color
  • rect(x0,y0,x1,y1,color); draw a rectangle x0,y0 to x1,y1 with color
  • fillrect(x0,y0,x1,y1,color); draw a filled rectangle
  • circle( x0,y0,radius ,color); draw a circle around x0,y0 with radius
  • fillcircle(x0,y0,radius ,color); draw a filled circle around x0,y0 with radius
  • setmode(mode); Set the drawing mode for all functions. mode can be NORMAL -> 0 is white and 1 is black or XOR -> the new pixel is a xor between the old display and the new. This mode will invert if a black pixel is draw over a black pixel.
  • print_bm(Bitmap ,x0,x0); Print a monochrome bitmap array. This graphic is defined by a Bitmap struct :

The pixel date array :

static char arm_logo[]={
0x00,0x00...
};

and a Bitmap struct:

Bitmap bitmARM = {
  48, // XSize
  48, // YSize 
  6,  // Bytes in Line
  arm_logo // Pointer to picture data 
};

To convert a graphic into a byte array we can use the tool Picture Converter 1bpp from http://www.embedded-tools.de.vu/ With this tool we load a image, press the convert button and save it as C-Header file. We have to save with horizontal orientation, so we have to press "No". Inside this file we find the data array which we can copy into a header file.

All this commands are writing to the frame buffer only ! To change the active display we have to call

  • write_disp(); This will refresh the display.

Sample code

test code for the LPC1768: http://mbed.org/users/dreschpe/code/epaper_mbed_test/

test code for KL25Z: http://mbed.org/users/dreschpe/code/epaper_mbed_130411_KL25Z/

#include "mbed.h"
#include "EaEpaper.h"
#include "Arial28x28.h"
#include "Arial12x12.h"
#include "font_big.h"
#include "graphics.h"

EaEpaper epaper(
                PTD7,            // PWR_CTRL
                PTD6,            // BORDER
                PTE31,           // DISCHARGE
                PTA17,           // RESET_DISP
                PTA16,           // BUSY
                PTC17,           // SSEL
                PTD4,            // PWM
                PTD2,PTD3,PTD1,  // MOSI,MISO,SCLK
                PTE0,PTE1);      // SDA,SDL 
 
int main() {

    epaper.cls();                                      // clear screen
    epaper.set_font((unsigned char*) Arial28x28);  // select the font
    epaper.locate(5,20);                           // set cursor
    epaper.printf("Hello Mbed");                  // print  text
    epaper.rect(3,15,150,50,1);                  // print a frame 
     
    epaper.set_font((unsigned char*) Arial12x12);  // change font
    epaper.locate(5,60);                               // set cursor
    epaper.printf("small Font");                    // print text
    epaper.set_font((unsigned char*) Neu42x35);  // change font
    epaper.locate(5,70);                               //set cursor
    epaper.printf("big Font");                        // change font
    
    epaper.write_disp(); // update screen       // update display
    
    wait(5);                                           // wait 5 s
    epaper.fillcircle(180,30,22,1);              // paint filled circle
    epaper.circle(160,150,20,1);               // paint circle
    epaper.write_disp(); // update screen      // update display
    
}
  
Committer:
dreschpe
Date:
Sat Nov 09 23:37:43 2013 +0000
Revision:
0:fedcef5319f5
Child:
1:90d18805a8a4
Lib for using a E-Paper display from Pervasive Displays.; There is a interface board from Embedded Artists.; It can handle graphic and text drawing and is using external fonts.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
dreschpe 0:fedcef5319f5 1 /* mbed library for 264*176 pixel 2.7 INCH E-PAPER DISPLAY from Pervasive Displays
dreschpe 0:fedcef5319f5 2 * Copyright (c) 2013 Peter Drescher - DC2PD
dreschpe 0:fedcef5319f5 3 *
dreschpe 0:fedcef5319f5 4 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
dreschpe 0:fedcef5319f5 5 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
dreschpe 0:fedcef5319f5 6 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
dreschpe 0:fedcef5319f5 7 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
dreschpe 0:fedcef5319f5 8 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
dreschpe 0:fedcef5319f5 9 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
dreschpe 0:fedcef5319f5 10 * THE SOFTWARE.
dreschpe 0:fedcef5319f5 11 */
dreschpe 0:fedcef5319f5 12
dreschpe 0:fedcef5319f5 13
dreschpe 0:fedcef5319f5 14 // 09.11.2013 initial Version
dreschpe 0:fedcef5319f5 15
dreschpe 0:fedcef5319f5 16 #ifndef EAEPAPER_H
dreschpe 0:fedcef5319f5 17 #define EAEPAPER_H
dreschpe 0:fedcef5319f5 18
dreschpe 0:fedcef5319f5 19 /**
dreschpe 0:fedcef5319f5 20 * Includes
dreschpe 0:fedcef5319f5 21 */
dreschpe 0:fedcef5319f5 22 #include "mbed.h"
dreschpe 0:fedcef5319f5 23 #include "EPD.h"
dreschpe 0:fedcef5319f5 24 #include "GraphicsDisplay.h"
dreschpe 0:fedcef5319f5 25
dreschpe 0:fedcef5319f5 26 // we have to double buffer the display
dreschpe 0:fedcef5319f5 27 #define EA_IMG_BUF_SZ (5808) // 264 x 176 / 8 = 5808
dreschpe 0:fedcef5319f5 28
dreschpe 0:fedcef5319f5 29 /** Draw mode
dreschpe 0:fedcef5319f5 30 * NORMAl
dreschpe 0:fedcef5319f5 31 * XOR set pixel by xor of the screen
dreschpe 0:fedcef5319f5 32 */
dreschpe 0:fedcef5319f5 33 enum {NORMAL,XOR};
dreschpe 0:fedcef5319f5 34
dreschpe 0:fedcef5319f5 35 /** Bitmap
dreschpe 0:fedcef5319f5 36 */
dreschpe 0:fedcef5319f5 37 struct Bitmap{
dreschpe 0:fedcef5319f5 38 int xSize;
dreschpe 0:fedcef5319f5 39 int ySize;
dreschpe 0:fedcef5319f5 40 int Byte_in_Line;
dreschpe 0:fedcef5319f5 41 char* data;
dreschpe 0:fedcef5319f5 42 };
dreschpe 0:fedcef5319f5 43
dreschpe 0:fedcef5319f5 44 /* color definitions */
dreschpe 0:fedcef5319f5 45 #define Black 0x0
dreschpe 0:fedcef5319f5 46 #define White 0x1
dreschpe 0:fedcef5319f5 47
dreschpe 0:fedcef5319f5 48 /** Display control class, based on GraphicsDisplay and TextDisplay
dreschpe 0:fedcef5319f5 49 *
dreschpe 0:fedcef5319f5 50 * Example:
dreschpe 0:fedcef5319f5 51 * @code
dreschpe 0:fedcef5319f5 52 * #include "mbed.h"
dreschpe 0:fedcef5319f5 53 * #include "EaEpaper.h"
dreschpe 0:fedcef5319f5 54 * #include "Arial28x28.h"
dreschpe 0:fedcef5319f5 55 * #include "Arial12x12.h"
dreschpe 0:fedcef5319f5 56 * #include "font_big.h"
dreschpe 0:fedcef5319f5 57 * #include "graphics.h"
dreschpe 0:fedcef5319f5 58
dreschpe 0:fedcef5319f5 59 * // the E-Paper board from embedded artists has a LM75 temp sensor to compensate the temperature effect. If it is cold the display reacts slower.
dreschpe 0:fedcef5319f5 60 * // The LM75 need a I2C -> 2 pins : sda and scl
dreschpe 0:fedcef5319f5 61 * // The display data is written via SPI -> 3 pins : mosi,miso,sck
dreschpe 0:fedcef5319f5 62 * // There are also some control signals
dreschpe 0:fedcef5319f5 63 * // The pwm pin has to be connected to a PWM enabled pin : pwm
dreschpe 0:fedcef5319f5 64 * // The other signals are connected to normal IO`s
dreschpe 0:fedcef5319f5 65 * //
dreschpe 0:fedcef5319f5 66 * EaEpaper epaper(PTD7, // PWR_CTRL
dreschpe 0:fedcef5319f5 67 * PTD6, // BORDER
dreschpe 0:fedcef5319f5 68 * PTE31, // DISCHARGE
dreschpe 0:fedcef5319f5 69 * PTA17, // RESET_DISP
dreschpe 0:fedcef5319f5 70 * PTA16, // BUSY
dreschpe 0:fedcef5319f5 71 * PTC17, // SSEL
dreschpe 0:fedcef5319f5 72 * PTD4, // PWM
dreschpe 0:fedcef5319f5 73 * PTD2,PTD3,PTD1, // MOSI,MISO,SCLK
dreschpe 0:fedcef5319f5 74 * PTE0,PTE1); // SDA,SDL
dreschpe 0:fedcef5319f5 75 *
dreschpe 0:fedcef5319f5 76 * int main() {
dreschpe 0:fedcef5319f5 77 *
dreschpe 0:fedcef5319f5 78 * epaper.cls(); // clear screen
dreschpe 0:fedcef5319f5 79 * epaper.set_font((unsigned char*) Arial28x28); // select the font
dreschpe 0:fedcef5319f5 80 * epaper.locate(5,20); // set cursor
dreschpe 0:fedcef5319f5 81 * epaper.printf("Hello Mbed"); // print text
dreschpe 0:fedcef5319f5 82 * epaper.rect(3,15,150,50,1); // draw frame
dreschpe 0:fedcef5319f5 83 * epaper.write_disp(); // update screen
dreschpe 0:fedcef5319f5 84 *
dreschpe 0:fedcef5319f5 85 * @endcode
dreschpe 0:fedcef5319f5 86 */
dreschpe 0:fedcef5319f5 87
dreschpe 0:fedcef5319f5 88
dreschpe 0:fedcef5319f5 89 class EaEpaper : public GraphicsDisplay {
dreschpe 0:fedcef5319f5 90
dreschpe 0:fedcef5319f5 91 public:
dreschpe 0:fedcef5319f5 92
dreschpe 0:fedcef5319f5 93 /**
dreschpe 0:fedcef5319f5 94 * Constructor.
dreschpe 0:fedcef5319f5 95 */
dreschpe 0:fedcef5319f5 96 EaEpaper(PinName p_on, PinName border, PinName discharge, PinName reset, PinName busy, PinName cs, // IO-Pins
dreschpe 0:fedcef5319f5 97 PinName pwm, // PWM Pin
dreschpe 0:fedcef5319f5 98 PinName mosi, PinName miso, PinName sck, // SPI
dreschpe 0:fedcef5319f5 99 PinName sda, PinName scl, // I2C
dreschpe 0:fedcef5319f5 100 const char* name ="E_Paper");
dreschpe 0:fedcef5319f5 101
dreschpe 0:fedcef5319f5 102 /** Get the width of the screen in pixel
dreschpe 0:fedcef5319f5 103 *
dreschpe 0:fedcef5319f5 104 * @param
dreschpe 0:fedcef5319f5 105 * @returns width of screen in pixel
dreschpe 0:fedcef5319f5 106 *
dreschpe 0:fedcef5319f5 107 */
dreschpe 0:fedcef5319f5 108 virtual int width();
dreschpe 0:fedcef5319f5 109
dreschpe 0:fedcef5319f5 110 /** Get the height of the screen in pixel
dreschpe 0:fedcef5319f5 111 *
dreschpe 0:fedcef5319f5 112 * @returns height of screen in pixel
dreschpe 0:fedcef5319f5 113 *
dreschpe 0:fedcef5319f5 114 */
dreschpe 0:fedcef5319f5 115 virtual int height();
dreschpe 0:fedcef5319f5 116
dreschpe 0:fedcef5319f5 117
dreschpe 0:fedcef5319f5 118 /**
dreschpe 0:fedcef5319f5 119 * Clear the display
dreschpe 0:fedcef5319f5 120 */
dreschpe 0:fedcef5319f5 121 void clear();
dreschpe 0:fedcef5319f5 122
dreschpe 0:fedcef5319f5 123 /**
dreschpe 0:fedcef5319f5 124 * Write image buffer to display
dreschpe 0:fedcef5319f5 125 */
dreschpe 0:fedcef5319f5 126 void write_disp(void);
dreschpe 0:fedcef5319f5 127
dreschpe 0:fedcef5319f5 128 /**
dreschpe 0:fedcef5319f5 129 * set or reset a single pixel
dreschpe 0:fedcef5319f5 130 *
dreschpe 0:fedcef5319f5 131 * @param x horizontal position
dreschpe 0:fedcef5319f5 132 * @param y vertical position
dreschpe 0:fedcef5319f5 133 * @param color : 0 white, 1 black
dreschpe 0:fedcef5319f5 134 */
dreschpe 0:fedcef5319f5 135 virtual void pixel(int x, int y, int color);
dreschpe 0:fedcef5319f5 136
dreschpe 0:fedcef5319f5 137 /** Fill the screen with white
dreschpe 0:fedcef5319f5 138 *
dreschpe 0:fedcef5319f5 139 */
dreschpe 0:fedcef5319f5 140 virtual void cls(void);
dreschpe 0:fedcef5319f5 141
dreschpe 0:fedcef5319f5 142 /** draw a 1 pixel line
dreschpe 0:fedcef5319f5 143 *
dreschpe 0:fedcef5319f5 144 * @param x0,y0 start point
dreschpe 0:fedcef5319f5 145 * @param x1,y1 stop point
dreschpe 0:fedcef5319f5 146 * @param color : 0 white, 1 black
dreschpe 0:fedcef5319f5 147 */
dreschpe 0:fedcef5319f5 148 void line(int x0, int y0, int x1, int y1, int color);
dreschpe 0:fedcef5319f5 149
dreschpe 0:fedcef5319f5 150 /** draw a rect
dreschpe 0:fedcef5319f5 151 *
dreschpe 0:fedcef5319f5 152 * @param x0,y0 top left corner
dreschpe 0:fedcef5319f5 153 * @param x1,y1 down right corner
dreschpe 0:fedcef5319f5 154 * @param color : 0 white, 1 black
dreschpe 0:fedcef5319f5 155 */
dreschpe 0:fedcef5319f5 156 void rect(int x0, int y0, int x1, int y1, int color);
dreschpe 0:fedcef5319f5 157
dreschpe 0:fedcef5319f5 158 /** draw a filled rect
dreschpe 0:fedcef5319f5 159 *
dreschpe 0:fedcef5319f5 160 * @param x0,y0 top left corner
dreschpe 0:fedcef5319f5 161 * @param x1,y1 down right corner
dreschpe 0:fedcef5319f5 162 * @param color : 0 white, 1 black
dreschpe 0:fedcef5319f5 163 */
dreschpe 0:fedcef5319f5 164 void fillrect(int x0, int y0, int x1, int y1, int color);
dreschpe 0:fedcef5319f5 165
dreschpe 0:fedcef5319f5 166 /** draw a circle
dreschpe 0:fedcef5319f5 167 *
dreschpe 0:fedcef5319f5 168 * @param x0,y0 center
dreschpe 0:fedcef5319f5 169 * @param r radius
dreschpe 0:fedcef5319f5 170 * @param color : 0 white, 1 black *
dreschpe 0:fedcef5319f5 171 */
dreschpe 0:fedcef5319f5 172 void circle(int x0, int y0, int r, int color);
dreschpe 0:fedcef5319f5 173
dreschpe 0:fedcef5319f5 174 /** draw a filled circle
dreschpe 0:fedcef5319f5 175 *
dreschpe 0:fedcef5319f5 176 * @param x0,y0 center
dreschpe 0:fedcef5319f5 177 * @param r radius
dreschpe 0:fedcef5319f5 178 * @param color : 0 white, 1 black *
dreschpe 0:fedcef5319f5 179 */
dreschpe 0:fedcef5319f5 180 void fillcircle(int x0, int y0, int r, int color);
dreschpe 0:fedcef5319f5 181
dreschpe 0:fedcef5319f5 182 /** set drawing mode
dreschpe 0:fedcef5319f5 183 * @param NORMAL : paint normal color, XOR : paint XOR of current pixels
dreschpe 0:fedcef5319f5 184 */
dreschpe 0:fedcef5319f5 185 void setmode(int mode);
dreschpe 0:fedcef5319f5 186
dreschpe 0:fedcef5319f5 187 /** setup cursor position
dreschpe 0:fedcef5319f5 188 *
dreschpe 0:fedcef5319f5 189 * @param x x-position (top left)
dreschpe 0:fedcef5319f5 190 * @param y y-position
dreschpe 0:fedcef5319f5 191 */
dreschpe 0:fedcef5319f5 192 virtual void locate(int x, int y);
dreschpe 0:fedcef5319f5 193
dreschpe 0:fedcef5319f5 194 /** calculate the max number of char in a line
dreschpe 0:fedcef5319f5 195 *
dreschpe 0:fedcef5319f5 196 * @returns max columns
dreschpe 0:fedcef5319f5 197 * depends on actual font size
dreschpe 0:fedcef5319f5 198 */
dreschpe 0:fedcef5319f5 199 virtual int columns();
dreschpe 0:fedcef5319f5 200
dreschpe 0:fedcef5319f5 201 /** calculate the max number of columns
dreschpe 0:fedcef5319f5 202 *
dreschpe 0:fedcef5319f5 203 * @returns max column
dreschpe 0:fedcef5319f5 204 * depends on actual font size
dreschpe 0:fedcef5319f5 205 */
dreschpe 0:fedcef5319f5 206 virtual int rows();
dreschpe 0:fedcef5319f5 207
dreschpe 0:fedcef5319f5 208 /** put a char on the screen
dreschpe 0:fedcef5319f5 209 *
dreschpe 0:fedcef5319f5 210 * @param value char to print
dreschpe 0:fedcef5319f5 211 * @returns printed char
dreschpe 0:fedcef5319f5 212 */
dreschpe 0:fedcef5319f5 213 virtual int _putc(int value);
dreschpe 0:fedcef5319f5 214
dreschpe 0:fedcef5319f5 215 /** paint a character on given position out of the active font to the screen buffer
dreschpe 0:fedcef5319f5 216 *
dreschpe 0:fedcef5319f5 217 * @param x x-position (top left)
dreschpe 0:fedcef5319f5 218 * @param y y-position
dreschpe 0:fedcef5319f5 219 * @param c char code
dreschpe 0:fedcef5319f5 220 */
dreschpe 0:fedcef5319f5 221 virtual void character(int x, int y, int c);
dreschpe 0:fedcef5319f5 222
dreschpe 0:fedcef5319f5 223 /** select the font to use
dreschpe 0:fedcef5319f5 224 *
dreschpe 0:fedcef5319f5 225 * @param f pointer to font array
dreschpe 0:fedcef5319f5 226 *
dreschpe 0:fedcef5319f5 227 * font array can created with GLCD Font Creator from http://www.mikroe.com
dreschpe 0:fedcef5319f5 228 * you have to add 4 parameter at the beginning of the font array to use:
dreschpe 0:fedcef5319f5 229 * - the number of byte / char
dreschpe 0:fedcef5319f5 230 * - the vertial size in pixel
dreschpe 0:fedcef5319f5 231 * - the horizontal size in pixel
dreschpe 0:fedcef5319f5 232 * - the number of byte per vertical line
dreschpe 0:fedcef5319f5 233 * you also have to change the array to char[]
dreschpe 0:fedcef5319f5 234 */
dreschpe 0:fedcef5319f5 235 void set_font(unsigned char* f);
dreschpe 0:fedcef5319f5 236
dreschpe 0:fedcef5319f5 237 /** print bitmap to buffer
dreschpe 0:fedcef5319f5 238 *
dreschpe 0:fedcef5319f5 239 * @param bm struct Bitmap in flash
dreschpe 0:fedcef5319f5 240 * @param x x start
dreschpe 0:fedcef5319f5 241 * @param y y start
dreschpe 0:fedcef5319f5 242 *
dreschpe 0:fedcef5319f5 243 */
dreschpe 0:fedcef5319f5 244 void print_bm(Bitmap bm, int x, int y);
dreschpe 0:fedcef5319f5 245
dreschpe 0:fedcef5319f5 246
dreschpe 0:fedcef5319f5 247 unsigned char* font;
dreschpe 0:fedcef5319f5 248 unsigned int draw_mode;
dreschpe 0:fedcef5319f5 249
dreschpe 0:fedcef5319f5 250 private:
dreschpe 0:fedcef5319f5 251
dreschpe 0:fedcef5319f5 252 EPD_Class epd_;
dreschpe 0:fedcef5319f5 253 I2C i2c_;
dreschpe 0:fedcef5319f5 254 unsigned int char_x;
dreschpe 0:fedcef5319f5 255 unsigned int char_y;
dreschpe 0:fedcef5319f5 256 int32_t readTemperature();
dreschpe 0:fedcef5319f5 257
dreschpe 0:fedcef5319f5 258 };
dreschpe 0:fedcef5319f5 259
dreschpe 0:fedcef5319f5 260 #endif /* EAEPAPER_H */