• sales

    +86-0755-88291180

4.2inch e-Paper (B)

Introduction


Note:
 The raw panel require a driver board, If you are the first time use this e-Paper, we recommend you to buy the HAT version or buy more one driver hat for easy use, otherwise you need to make the driver board yourself. And this instruction is based on the version with PCB or driver board.

400x300, 4.2inch E-Ink display module, three-color, SPI interface


Interfaces


VCC3.3V
GNDGND
DINSPI MOSI
CLKSPI SCK
CSSPI chip select (Low active)
DCData/Command control pin (High for data, and low for command)
RSTExternal reset pin (Low for reset)
BUSYBusy state output pin (Low for busy)


Working principle


Introduction


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 suspending in the transparent oil and would move depending on the electronic charge. The E-paper screen display patterns by reflecting the ambient light, so it has no background light requirement. Under sunshine, the E-paper screen still has high visibility with a wide viewing angle of 180 degree. It is the ideal choice for E-reading.


Communication protocol





Note: Different from the traditional SPI protocol, the data line from the slave to the master is hidden since the device only has display requirement.

  • 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.

SPI communication has data transfer timing, which is combined by CPHA and CPOL.

  1. CPOL determines the level of the serial synchronous clock at idle state. When CPOL = 0, the level is Low. However, CPOL has little effect to the transmission.
  2. CPHA determines whether data is collected at the first clock edge or at the second clock edge of serial synchronous clock; when CPHL = 0, data is collected at the first clock edge.
  • There are 4 SPI communication modes. SPI0 is commonly used, in which CPHL = 0, CPOL = 0.

As you can see from the figure above, data transmission starts at the first falling edge of SCLK, and 8 bits of data are transferred in one clock cycle. In here, SPI0 is in used, and data is transferred by bits, MSB first.


  • e-Paper HAT Codes description

  • e-Paper HAT Hardware/software setup
  • TAG: Raspberry Pi Pico Raspberry Pi 24.5 inch Type C/HDMI 2K Display 24.5inch Screen 2560x1440 Computer PC Phone For Xbox/PS4/Switch Raspberry Pi 0.96inch LCD Milk V Duo Raspberry Pi 5 PCIe to M.2 NVMe SSD Adapter Board HAT Milk-V Duo S UART Serial Console​ Raspberry Pi RP2040 LoRa Jetson Orin Industrial-grade isolated 2-way RS485 hub repeater One RS485 TO Two RS485 Raspberry Pi 5 PCIe to M.2 5G/4G/3G HAT With RM520N-GL Industrial Isolated RS485 TO ETH (C) RJ45 Converter Wall/Rail-Mount For Modbus spotpear 2.15 inch e-Paper HAT+ B E-Ink Red/Black/White 296×160 Screen Display For Arduino /Raspberry Pi /Jetson Nano /STM32 Jetson Orin 4G/3G/2G expansion board GNSS GPS SIM7600G-H-M.2 ESP32 Google Dinosaur game ESP32-C3FN4 Bus Servo Adapter A FT232RNL USB TO TTL Industrial UART Can For Raspberry Pi 5 Terminal Debug Raspberry Pi 4B MPS2280 POE Raspberry Pi 5 PCIe to M.2 NVMe SSD Adapter Board HAT Pi5 2280/2242/2230