• sales

    +86-0755-88291180

7.5inch HD 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.

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: development board Raspberry Pi Pico 2 RP2350 2.8 inch LCD Capacitive TouchScreen Development Board 240x320 Display QMI8658 6-Axis /PCM5101 Audio /SD /RTC /Battery Port X1012 Raspberry Pi 5 POE And PCIe to M.2 NVMe SSD Board Pi5 2280 Power over Ethernet voice module Rockchip Raspberry-Pi-Game-1.54inch-LCD-touchscreen-display-ST7789 Raspberry Pi Pico 2 RP2350 1.28 inch Round LCD TouchScreen Development Board 240x240 Display QMI8658 6-Axis $17.9 Raspberry Pi MLX90641 Raspberry Pi Raspberry Pi 11.6 inch LCD HDMI /Type C Display In-Cell Capacitive TouchScreen 1768x828 For Jetson Nano/mini Computer PC RV1106 SC3336 360° Pi5 Active Cooler STM32 0.96inch RGB OLED Raspberry Pi Real time clock Milk-V Duo Wiki ESP32-S3 Round LCD Raspberry Pi Screen CAM-GC2083 Raspberry Pi Pico 2 RP2350-One Mini Board Type-A RP2350A