4.2inch e-Paper Module

Introduction

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

Features

• 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:
  

For computer, the data is saved in MSB format:

So we can use two bytes for 16 pixels.

User Guides

• Raspberry Pi guide
• Jetson Nano guide
• STM32 guide
• Arduino guide

Resources

Documents

• Schematic
  
• 4.2inch e-Paper Datasheet

Demo codes

• Demo codes

FAQ

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.