CSB (CS): Slave chip select signal, active at low level. When it is at low level, the chip is enabled.
SCL (SCK/SCLK): Serial clock signal.
D/C (DC): Data/command control signal, write command (Command) when the level is low; write data (Data/parameter) when the level is high.
SDA (DIN): Serial data signal.
Timing: CPHL=0, CPOL=0, i.e. SPI mode 0.
Note: For specific information about SPI communication, you can search for information online on your own.

The e-paper used in this product uses "microcapsule electrophoresis display" technology for image display. The basic principle is that charged nanoparticles suspended in a liquid migrate under the action of an electric field. The e-paper display screen displays patterns by reflecting ambient light and does not require a backlight. Under ambient light, the e-paper display screen is clearly visible, with a viewing angle of almost 180°. Therefore, e-paper displays are ideal for reading.

• For black and white images, we can define it as 0 if it is black and 1 if it is white, so there is a way to represent colors:
  
  • White: □ corresponds to 1
    
  • Black: ■ corresponds to 0
    
• A dot is generally called a pixel on the graph, and the color is either 1 or 0, that is, 1 bit can identify the color: 1Pixel = 1bit, then a byte contains 8 pixels.
  
• Take 16 pixels as an example. We assume that the first 8 pixels are black and the last 8 pixels are white. Then it can be thought that pixels 1-16 correspond to bits 0 to 15, and 0 means black. 1 means white:
  

For the computer, the way it stores data is that the high bits come first and the low bits come last, and each byte only has 8 bits, so there may be a slight change:

In this way, only 2 bytes are required to represent 16 pixels.

The 10.85inch e-Paper is a dual-IC controlled e-Paper screen, in addition to the above programming principle, please note the following

• As shown in the figure above, each IC controls half of the screen, and the two CS pins are used to control the corresponding M area (master area) and S area (slave area)
• Except for CS pins, other control pins are shared
• Except for common commands (initialization command and refresh command in the demo), only one CS pin is allowed to be pulled low at a time
• When transmitting images, it should be noted that the display direction of the screen is horizontal display (X-axis direction), and after reaching the end point of a region, it will be displayed in the next line. Therefore, it is necessary to cut the picture into two pictures and transmit them separately, otherwise it will be displayed misalignment

1. The screen supports partial refresh. Please note that when using it, you cannot always use partial refresh to refresh the screen. You need to perform a global refresh of the screen after several partial refreshes. Otherwise, the screen display effect will be abnormal.
2. Note that the screen cannot be powered on for a long time. When the screen does not refresh, the screen must be set to sleep mode or power off. Otherwise, the screen will remain in a high voltage state for a long time, which will damage the diaphragm and cannot be repaired.
3. When using the e-paper screen, it is recommended that the refresh interval is at least 180s, and refreshed at least every 24 hours. If the e-paper screen is not used for a long time, it should be whitened and stored. (Refer to the data sheet for specific storage environment requirements)
4. After the screen enters sleep mode, the image data sent will be ignored, and it can only be refreshed normally after re-initialization.
5. Control the 0x3C or 0x50 (refer to the data sheet for details) register to adjust the border color. In the example demo, you can adjust the Border Waveform Control register or VCOM AND DATA INERTVAL SETTING to set it.
6. If you find that the data of the created image is displayed incorrectly on the screen, it is recommended to check whether the image size is set correctly, and try again by changing the width and height settings.
7. The working voltage requirement for an ink screen is 3.3V. If you purchase a raw display and need to work in a 5V environment when designing the circuit, it is recommended to perform level conversion processing. The new version of the driver board (Rev2.1 and subsequent versions) has added a level processing circuit, which can support both 3.3V and 5V working environments simultaneously. The old version can only support 3.3V working environment. When using it, you can first confirm the version number (which is under the board name).
8. The FPC cable of the screen is relatively fragile. Please note: do not bend the cable in the vertical direction of the screen to avoid the cable being torn; do not repeatedly bend the cable excessively to avoid the cable breaking; do not bend the cable toward the front of the screen to prevent the cable from being disconnected from the panel. During debugging and R&D, it is recommended to fix the wiring before use.
9. The ink screen screen is relatively fragile, so be careful to avoid falling, colliding, or pressing hard.
10. We recommend that customers first use the sample demo we provide and use the corresponding development board to test after getting the screen.