eINK click

eINK click is an adapter for connecting eINK displays, with a 24pin ribbon cable. The eINK display sold with the click can retain the image even when the power is off. The click board™ is designed to run on a 3.3V power supply. It communicates over SPI interface.

eINK displays 

The display uses electronic ink, which makes the display “Bistable”. It means that the display consumes power only when something is changing on the screen. This reduces the power consumption of the target device considerably. So, the display retains the image even when the power is off.

eINK displays have good sunlight readability, it's like you are reading something on real paper. It is the same type of display used in you ebook reader, like the Kindle™.

How the click works

The display communicates with the eINK click over SPI interface. The onboard LM75 temperature sensor is used for temperature calibration from the look-up table.

The click can be used with different eINK displays we plan to release in the future.

Display features 

The eINK display (EA EPA20-A) is a high-contrast e-paper display. It has a wide viewing angle and the resolution of 172X72 dots. The color of the display has four scales: black, dark gray, light gray, and white.

The power consumption, while the display is on, is around 40mW.

Specifications

Pinout diagram

This table shows how the pinout on eINK click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes	Pin					Pin	Notes
	NC	1	AN	PWM	16	D/C#	Data/configuration
Reset	RES#	2	RST	INT	15	BUSY	Busy indicator from the screen
SPI enable	CS#	3	CS	TX	14	NC
SPI Clock	SCK	4	SCK	RX	13	NC
	NC	5	MISO	SCL	12	NC
SPI data input	SDI	6	MOSI	SDA	11	NC
Power supply	+3.3V	7	3.3V	5V	10	NC
Ground	GND	8	GND	GND	9	GND	Ground

Programming

Code examples for eINK click, written for MikroElektronika hardware and compilers are available on Libstock.

Code snippet

This code snippet initializes the MCU and eINK click and in an endless loop displays black letters, white letters and external image, respectively.

01 void main()
02 {
03     sysinit();
04     eink_init();
05     Delay_ms( 1000 );
06
07     while( 1 )
08     {
09         // Display black letters on white background
10         eink_fill_screen( EINK_COLOR_WHITE );
11         eink_set_font( guiFont_Exo_2_Condensed21x32_Regular, EINK_COLOR_BLACK, FO_HORIZONTAL );
12         eink_text( "EINK", 14, 50 );
13         delay_ms( 3000 );
14
15         // Display white letters on black background
16         eink_fill_screen( EINK_COLOR_BLACK );
17         eink_set_font( guiFont_Exo_2_Condensed21x32_Regular, EINK_COLOR_WHITE, FO_HORIZONTAL );
18         eink_text( "EINK", 14, 50 );
19         Delay_ms( 3000 );
20
21         // Display external image
22         eink_image_bmp( _mikroe_bmp );
23         Delay_ms( 3000 );
24     }
25 }