• sales

    +86-0755-88291180

4.2inch e-Paper (C)

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 5 5V5A Raspberry Pi 5 PCIe to 2-CH PCIe FFC Dual PCIe HAT Board Pi5 Double Milk-V Duo 14 inch Dual LCD Computer PC Monitor Display Double Secondary Screen Type C Mini HDMI 1080P For Windows/MacOS SC09 Serial UART Bus Servo Motor Switchable 2.3kg 300Angle Raspberry Pi LCD Display Screen 1.3inch LCD with Game Button AND Audio Buzzer For Zero 2W / 3B / 4B / PI5 / RP2040-PiZero RS232 to Ethernet Modbus-Series-BootLoader-Description User Guide Milk-V Duo S Usage of USB Type A interface ESP32 S3 Development Board 2.8 inch Round LCD Display 480x480 QMI8658 Sensor / SD /MP3 Audio /Battery Port LVGL/HMI For Arduino Raspberry Pi MLX90641 Raspberry Pi Camera Arduino MEGA2560 R3 X1005 Raspberry Pi 5 PCIe to M.2 NVMe Dual SSD Adapter Board HAT Pi5 Double 2230/2242/2260/2280 ESP32 IR Thermal Imaging Camera Robotic Arm Control RV1106 SC3336 and Audio Speaker Pi5 ESP32 Mini TV