4.2inch e-Paper Module

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This is 4.2inch e-Paper module, 400x300 resolution, SPI interface, supports black and white colors.


  • Szie: 4.2inch
  • Diemnsion(Raw panel):90.1mm × 77.0mm × 1.18mm
  • Dimenstion(PCBA):103.0mm x 78.5mm
  • Display area:84.8mm x 63.6mm
  • Operating voltage:3.3V/5V
  • Interface:SPI
  • Pitch:0.212 x 0.212
  • Resolution:400 x 300
  • Color: Black, White
  • Grayscale:2
  • Fully update: 4s
  • Consumption (update): 26.4mW(typ.)
  • Consumption (standby):<=0.017mW

【Notices】:</ br> Update time: The data provided is for reference, the actual time may be different according to the MCU. The e-Paper will flicker when updating, it is normal
Consumption: The data provided is for reference, the actual consumption may be different according to the driver board.

SPI timing


The e-Paper only supports writing, therefore the MISO pin is hidden.
CS is slave chip select, when CS is low, the chip is enabled.
DC is data/command control pin, when DC = 0, write command, when DC = 1, write data.
SCLK is the SPI communication clock.
SDIN is the data line from the master to the slave in SPI communication.
Timing:CPHL=0, CPOL=0 (SPI0)
【Note】You can search more documents of SPI bus online.

Working protocol

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 first 8 pixels to black and the last 8 pixels to white, we show it by codes, they will be 16 bit as below:

E-paper hardware work 1.png
For computer, the data is saved in MSB format:
E-paper hardware work 2.png
So we can use two bytes for 16 pixels.

User Guides



Demo codes


1、Working requirements of e-Paper?|

  • 【Working】Temperature: 0~50°C; Humidity: 35%~65%RH
  • 【Storage】Temperature: ≤30°C; Humidity: ≤55%RH; Max storage time: 6 months
  • 【Transport】Temperature: -25~70°C; Max transport time: 10 days
  • 【Unpack】Temperature: 20°C±5°C; Humidity: 50%RH±5%RH; Max storage time: Should be assembled in 72h

2、 What do you need to note about e-Paper refreshing

  • Refresh mode
    • Full refresh: e-Paper flicker when full refreshing to remove ghost image for best display.
    • Partial refresh: It doesn't flicker if you use partial refresh (only some of the two-color e-paper support partial refresh). Note that you cannot use Partial refresh all the time, you should full refresh e-paper regularly, otherwise, ghost problem will get worse even damage
  • Refresh rate
    • When using, you should set the update interval at least 180s. (except Partial supportable types)
    • Please set the e-Paper to sleep mode or power off it directly, otherwise, the e-Paper is damaged because of working in high voltage for a long time.
    • You need to update the content of three-color e-Paper at least one time every 24h to avoid the burn-in problem.
  • Working place
    • We recommend you to use the e-Paper indoor. If you need to set the e-paper outdoor, Please place the e-paper in shadow and protect it from UV. When you designed you e-paper product, you should take care about the working situation like temperature, humidity, etc.

3、Why the e-Paper display a black frame?

  • You can configure Border Waveform Control register or VCOM AND DATA INTERVAL SETTING register to change the frame.

4、Could the e-Paper work again after sleeping?

  • You can use the initial function to wake it up and then update.