Template: Pico e-Paper 5.65 Spec

Overview

This 5.65inch colorful e-Paper display module is designed for Raspberry Pi Pico, 600 x 448 Pixels, and supports ACeP 7-Color.

Specifications

• Dimension: 5.65inch
• Outline dimensions(raw panel): 125.4 x 99.5mm x 0.91mm
• Outline dimensions(driver board): 128mm x 101.5mm
• Display Size: 114.9mm x 85.79mm
• Operating voltage: 3.3V/5V
• Interface: SPI
• Dot pitch: 0.1915 x 0.1915
• Display color: ACeP 7-Color
• Resolution: 600 x 448 pixels
• Display color: Black/White/Green/Blue/Red/Yellow/Orange
• Full refresh time: 33s
• Refresh power: 26.4mW (typ.)
• Standby current: <0.01uA (almost none)

【Note】: Refresh time: The refresh time is the experimental test data, the actual refresh time will have errors, and the actual effect shall prevail. There will be a flickering effect during the global refresh process, this is a normal phenomenon.
Power consumption: The power consumption data is the experimental test data. The actual power consumption will have a certain error due to the existence of the driver board and the actual use situation. The actual effect shall prevail.

SPI Communication Timing

Since the ink screen only needs to be displayed, the data cable (MISO) sent from the machine and received by the host is hidden here.

• CS: Slave chip select, when CS is low, the chip is enabled.
• DC: data/command control pin, write command when DC=0; write data when DC=1.
• SCLK: SPI communication clock
• SDIN: SPI communication master sends, the slave receives.
• Timing: CPHL=0, CPOL=0 (SPI0)

[Remarks] For specific information about SPI, you can search for information online.

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 displays 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.)

Pixel & Byte

We define the pixels in a monochrome picture, 0 is black and 1 is white.
White：□: Bit 1
Black：■: Bit 0

• The dot in the figure is called a pixel. As we know, 1 and 0 are used to define the color, therefore we can use one bit to define the color of one pixel, and 1 byte = 8pixels
  
• For example, If we set the first 8 pixels to black and the last 8 pixels to white, we show it by codes, they will be 16-bit as below:
  

For the computer, the data is saved in MSB format:

So we can use two bytes for 16 pixels.

Color of e-Paper

An image is made of pixels. The sizes of every pixel defined may color are supported by the e-Paper. Monochrome images use one bit for one pixel (0 and 1, black and white), in this case, if we want to display more colors, we should use more bits for every pixel.
You can refer to the Make BMP file for e-Paper" guide and make the image yourself for this module.
We need at least 3bits to display severe color. For easy programming, we and an 0 bit in front of it. In this case, we use 4 bits for every pixel.

Color	BIN	HEX	The color (reference)
Black	0b0000	0x0
White	0b0001	0x1
Green	0b0010	0x2
Blue	0b0011	0x3
Red	0b0100	0x4
Yellow	0b0101	0x5
Orange	0b0110	0x6

For example, if you want to display four colors, green, yellow, red and orange, it should be like as below:

Pixel	1				2				3				4
Bit	0	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15
Data	0	0	1	0	0	1	0	1	0	1	0	0	0	1	1	0
Color

Data is saved in MSB formate and 1byte is equal to 8 bits.

Pixel	1				2				3				4
Bit	7	6	5	4	3	3	1	0	7	6	5	4	3	2	1	0
Data	0	0	1	0	0	1	0	1	0	1	0	0	0	1	1	0
Color
Byte	0x25								0x46

Precautions

1. For E-paper displays that support partial refresh, please note that you cannot refresh them with the partial refresh mode all the time. After refreshing partially several times, you need to fully refresh EPD once. Otherwise, the display effect will be abnormal, which cannot be repaired!
   
2. It is a normal phenomenon that the three-color EPD will have a certain color difference in different batches. Hence, It is recommended to use the program to clear all the pictures on the EPD and store it facing up. Please clear the screen several times before powering on.
3. Note that the screen cannot be powered on for a long time. When the screen is not refreshed, please set the screen to sleep mode or power off it. Otherwise, the screen will remain in a high voltage state for a long time, which will damage the e-Paper and cannot be repaired!
   
4. When using the e-Paper display, it is recommended that the refresh interval be at least 180s, and refresh at least once every 24 hours. If the e-Paper is not used for a long time, you should use the program to clear the screen before storing it. (Refer to the datasheet for specific storage environment requirements.)
   
5. After the screen enters sleep mode, the sent image data will be ignored, and it can be refreshed normally only after initializing again.
   
6. Control the 0x3C or 0x50 (refer to the datasheet for details) register to adjust the border color. In the demo, you can adjust the Border Waveform Control register or VCOM AND DATA INTERVAL SETTING to set the border.
   
7. If you find that the created image data is displayed incorrectly on the screen, it is recommended to check whether the image size setting is correct, change the width and height settings of the image and try again.
   
8. The working voltage of the e-Paper display is 3.3V. If you buy the raw panel and you need to add a level convert circuit for compatibility with 5V voltage. The new version of the driver board (V2.1 and subsequent versions) has added a level processing circuit, which can support both 3.3V and 5V. The old version only supports a 3.3V working environment. You can confirm the version before using it. (The one with the 20-pin chip on the PCB is generally the new version.)
   
9. The FPC cable of the screen is relatively fragile, pay attention to bending the cable along the horizontal direction of the screen when using it, and do not bend the cable along the vertical direction of the screen.
   
10. The screen of e-Paper is relatively fragile, please try to avoid dropping, bumping, and pressing hard.
    
11. We recommend that customers use the sample program provided by us to test with the corresponding development board.